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1.  Specificity of Clinical Breast Examination in Community Practice 
Background
Millions of women receive clinical breast examination (CBE) each year, as either a breast cancer screening test or a diagnostic test for breast symptoms. While screening CBE had moderately high specificity (∼94%) in clinical trials, community clinicians may be comparatively inexperienced and may conduct relatively brief examinations, resulting in even higher specificity but lower sensitivity.
Objective
To estimate the specificity of screening and diagnostic CBE in clinical practice and identify patient factors associated with specificity.
Design
Retrospective cohort study.
Subjects
Breast-cancer-free female health plan enrollees in 5 states (WA, OR, CA, MA, and MN) who received CBE (N = 1,484).
Measurements
Medical charts were abstracted to ascertain breast cancer risk factors, examination purpose (screening vs diagnostic), and results (true-negative vs false-positive). Women were considered “average-risk” if they had neither a family history of breast cancer nor a prior breast biopsy and “increased-risk” otherwise.
Results
Among average- and increased-risk women, respectively, the specificity (true-negative proportion) of screening CBE was 99.4% [95% confidence interval (CI): 98.8–99.7%] and 97.1% (95% CI: 95.7–98.0%), and the specificity of diagnostic CBE was 68.7% (95% CI: 59.7–76.5%) and 57.1% (95% CI: 51.1–63.0%). The odds of a true-negative screening CBE (specificity) were significantly lower among women at increased risk of breast cancer (adjusted odds ratio 0.21; 95% CI: 0.10–0.46).
Conclusions
Screening CBE likely has higher specificity among community clinicians compared to examiners in clinical trials of breast cancer screening, even among women at increased breast cancer risk. Highly specific examinations, however, may have relatively low sensitivity for breast cancer. Diagnostic CBE, meanwhile, is relatively nonspecific.
doi:10.1007/s11606-006-0062-7
PMCID: PMC1824753  PMID: 17356964
breast cancer; sensitivity and specificity; screening; physical examination
2.  Screening Mammography for Women Aged 40 to 49 Years at Average Risk for Breast Cancer 
Executive Summary
Objective
The aim of this review was to determine the effectiveness of screening mammography in women aged 40 to 49 years at average risk for breast cancer.
Clinical Need
The effectiveness of screening mammography in women aged over 50 years has been established, yet the issue of screening in women aged 40 to 49 years is still unsettled. The Canadian Task Force of Preventive Services, which sets guidelines for screening mammography for all provinces, supports neither the inclusion nor the exclusion of this screening procedure for 40- to 49-year-old women from the periodic health examination. In addition to this, 2 separate reviews, one conducted in Quebec in 2005 and the other in Alberta in 2000, each concluded that there is an absence of convincing evidence on the effectiveness of screening mammography for women in this age group who are at average risk for breast cancer.
In the United States, there is disagreement among organizations on whether population-based mammography should begin at the age of 40 or 50 years. The National Institutes of Health, the American Association for Cancer Research, and the American Academy of Family Physicians recommend against screening women in their 40s, whereas the United States Preventive Services Task Force, the National Cancer Institute, the American Cancer Society, the American College of Radiology, and the American College of Obstetricians and Gynecologists recommend screening mammograms for women aged 40 to 49 years. Furthermore, in comparing screening guidelines between Canada and the United States, it is also important to recognize that “standard care” within a socialized medical system such as Canada’s differs from that of the United States. The National Breast Screening Study (NBSS-1), a randomized screening trial conducted in multiple centres across Canada, has shown there is no benefit in mortality from breast cancer from annual mammograms in women randomized between the ages of 40 and 49, relative to standard care (i.e. physical exam and teaching of breast-self examination on entry to the study, with usual community care thereafter).
At present, organized screening programs in Canada systematically screen women starting at 50 years of age, although with a physician’s referral, a screening mammogram is an insured service in Ontario for women under 50 years of age.
International estimates of the epidemiology of breast cancer show that the incidence of breast cancer is increasing for all ages combined, whereas mortality is decreasing, though at a slower rate. These decreasing mortality rates may be attributed to screening and advances in breast cancer therapy over time. Decreases in mortality attributable to screening may be a result of the earlier detection and treatment of invasive cancers, in addition to the increased detection of ductal carcinoma in situ (DCIS), of which certain subpathologies are less lethal. Evidence from the SEER cancer registry in the United States indicates that the age-adjusted incidence of DCIS has increased almost 10-fold over a 20-year period (from 2.7 to 25 per 100,000).
The incidence of breast cancer is lower in women aged 40 to 49 years than in women aged 50 to 69 years (about 140 per 100,000 versus 500 per 100,000 women, respectively), as is the sensitivity (about 75% versus 85% for women aged under and over 50, respectively) and specificity of mammography (about 80% versus 90% for women aged under and over 50, respectively). The increased density of breast tissue in younger women is mainly responsible for the lower accuracy of this procedure in this age group. In addition, as the proportion of breast cancers that occur before the age of 50 are more likely to be associated with genetic predisposition as compared with those diagnosed in women after the age of 50, mammography may not be an optimal screening method for younger women.
Treatment options vary with the stage of disease (based on tumor size, involvement of surrounding tissue, and number of affected axillary lymph nodes) and its pathology, and may include a combination of surgery, chemotherapy, and/or radiotherapy.
Surgery is the first-line intervention for biopsy confirmed tumours. The subsequent use of radiation, chemotherapy, or hormonal treatments is dependent on the histopathologic characteristics of the tumor and the type of surgery. There is controversy regarding the optimal treatment of DCIS, which is noninvasive.
With such controversy as to the effectiveness of mammography and the potential risk associated with women being overtreated or actual cancers being missed, and the increased risk of breast cancer associated with exposure to annual mammograms over a 10-year period, the Ontario Health Technology Advisory Committee requested this review of screening mammography in women aged 40 to 49 years at average risk for breast cancer. This review is the first of 2 parts and concentrates on the effectiveness of screening mammography (i.e., film mammography, FM) for women at average risk aged 40 to 49 years. The second part will be an evaluation of screening by either magnetic resonance imaging or digital mammography, with the objective of determining the optimal screening modality in these younger women.
Review Strategy
The following questions were asked:
Does screening mammography for women aged 40 to 49 years who are at average risk for breast cancer reduce breast cancer mortality?
What is the sensitivity and specificity of mammography for this age group?
What are the risks associated with annual screening from ages 40 to 49?
What are the risks associated with false positive and false negative mammography results?
What are the economic considerations if evidence for effectiveness is established?
The Medical Advisory Secretariat followed its standard procedures and searched these electronic databases: Ovid MEDLINE, EMBASE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the International Network of Agencies for Health Technology Assessment.
Keywords used in the search were breast cancer, breast neoplasms, mass screening, and mammography.
In total, the search yielded 6,359 articles specific to breast cancer screening and mammography. This did not include reports on diagnostic mammograms. The search was further restricted to English-language randomized controlled trials (RCTs), systematic reviews, and meta-analyses published between 1995 and 2005. Excluded were case reports, comments, editorials, and letters, which narrowed the results to 516 articles and previous health technology policy assessments.
These were examined against the criteria outlined below. This resulted in the inclusion of 5 health technology assessments, the Canadian Preventive Services Task Force report, the United States Preventive Services Task Force report, 1 Cochrane review, and 8 RCTs.
Inclusion Criteria
English-language articles, and English and French-language health technology policy assessments, conducted by other organizations, from 1995 to 2005
Articles specific to RCTs of screening mammography of women at average risk for breast cancer that included results for women randomized to studies between the ages of 40 and 49 years
Studies in which women were randomized to screening with or without mammography, although women may have had clinical breast examinations and/or may have been conducting breast self-examination.
UK Age Trial results published in December 2006.
Exclusion Criteria
Observational studies, including those nested within RCTs
RCTs that do not include results on women between the ages of 40 and 49 at randomization
Studies in which mammography was compared with other radiologic screening modalities, for example, digital mammography, magnetic resonance imaging or ultrasound.
Studies in which women randomized had a personal history of breast cancer.
Intervention
Film mammography
Comparators
Within RCTs, the comparison group would have been women randomized to not undergo screening mammography, although they may have had clinical breast examinations and/or have been conducting breast self-examination.
Outcomes of Interest
Breast cancer mortality
Summary of Findings
There is Level 1 Canadian evidence that screening women between the ages of 40 and 49 years who are at average risk for breast cancer is not effective, and that the absence of a benefit is sustained over a maximum follow-up period of 16 years.
All remaining studies that reported on women aged under 50 years were based on subset analyses. They provide additional evidence that, when all these RCTs are taken into account, there is no significant reduction in breast cancer mortality associated with screening mammography in women aged 40 to 49 years.
Conclusions
There is Level 1 evidence that screening mammography in women aged 40 to 49 years at average risk for breast cancer is not effective in reducing mortality.
Moreover, risks associated with exposure to mammographic radiation, the increased risk of missed cancers due to lower mammographic sensitivity, and the psychological impact of false positives, are not inconsequential.
The UK Age Trial results published in December 2006 did not change these conclusions.
PMCID: PMC3377515  PMID: 23074501
3.  Cancer Screening with Digital Mammography for Women at Average Risk for Breast Cancer, Magnetic Resonance Imaging (MRI) for Women at High Risk 
Executive Summary
Objective
The purpose of this review is to determine the effectiveness of 2 separate modalities, digital mammography (DM) and magnetic resonance imaging (MRI), relative to film mammography (FM), in the screening of women asymptomatic for breast cancer. A third analysis assesses the effectiveness and safety of the combination of MRI plus mammography (MRI plus FM) in screening of women at high risk. An economic analysis was also conducted.
Research Questions
How does the sensitivity and specificity of DM compare to FM?
How does the sensitivity and specificity of MRI compare to FM?
How do the recall rates compare among these screening modalities, and what effect might this have on radiation exposure? What are the risks associated with radiation exposure?
How does the sensitivity and specificity of the combination of MRI plus FM compare to either MRI or FM alone?
What are the economic considerations?
Clinical Need
The effectiveness of FM with respect to breast cancer mortality in the screening of asymptomatic average- risk women over the age of 50 has been established. However, based on a Medical Advisory Secretariat review completed in March 2006, screening is not recommended for women between the ages of 40 and 49 years. Guidelines published by the Canadian Task Force on Preventive Care recommend mammography screening every 1 to 2 years for women aged 50 years and over, hence, the inclusion of such women in organized breast cancer screening programs. In addition to the uncertainty of the effectiveness of mammography screening from the age of 40 years, there is concern over the risks associated with mammographic screening for the 10 years between the ages of 40 and 49 years.
The lack of effectiveness of mammography screening starting at the age of 40 years (with respect to breast cancer mortality) is based on the assumption that the ability to detect cancer decreases with increased breast tissue density. As breast density is highest in the premenopausal years (approximately 23% of postmenopausal and 53% of premenopausal women having at least 50% of the breast occupied by high density), mammography screening is not promoted in Canada nor in many other countries for women under the age of 50 at average risk for breast cancer. It is important to note, however, that screening of premenopausal women (i.e., younger than 50 years of age) at high risk for breast cancer by virtue of a family history of cancer or a known genetic predisposition (e.g., having tested positive for the breast cancer genes BRCA1 and/or BRCA2) is appropriate. Thus, this review will assess the effectiveness of breast cancer screening with modalities other than film mammography, specifically DM and MRI, for both pre/perimenopausal and postmenopausal age groups.
International estimates of the epidemiology of breast cancer show that the incidence of breast cancer is increasing for all ages combined whereas mortality is decreasing, though at a slower rate. The observed decreases in mortality rates may be attributable to screening, in addition to advances in breast cancer therapy over time. Decreases in mortality attributable to screening may be a result of the earlier detection and treatment of invasive cancers, in addition to the increased detection of ductal carcinoma in situ (DCIS), of which certain subpathologies are less lethal. Evidence from the Surveillance, Epidemiology and End Results (better known as SEER) cancer registry in the United States, indicates that the age-adjusted incidence of DCIS has increased almost 10-fold over a 20 year period, from 2.7 to 25 per 100,000.
There is a 4-fold lower incidence of breast cancer in the 40 to 49 year age group than in the 50 to 69 year age group (approximately 140 per 100,000 versus 500 per 100,000 women, respectively). The sensitivity of FM is also lower among younger women (approximately 75%) than for women aged over 50 years (approximately 85%). Specificity is approximately 80% for younger women versus 90% for women over 50 years. The increased density of breast tissue in younger women is likely responsible for the decreased accuracy of FM.
Treatment options for breast cancer vary with the stage of disease (based on tumor size, involvement of surrounding tissue, and number of affected axillary lymph nodes) and its pathology, and may include a combination of surgery, chemotherapy and/or radiotherapy. Surgery is the first-line intervention for biopsy-confirmed tumors. The subsequent use of radiation, chemotherapy or hormonal treatments is dependent on the histopathologic characteristics of the tumor and the type of surgery. There is controversy regarding the optimal treatment of DCIS, which is considered a noninvasive tumour.
Women at high risk for breast cancer are defined as genetic carriers of the more commonly known breast cancer genes (BRCA1, BRCA2 TP53), first degree relatives of carriers, women with varying degrees of high risk family histories, and/or women with greater than 20% lifetime risk for breast cancer based on existing risk models. Genetic carriers for this disease, primarily women with BRCA1 or BRCA2 mutations, have a lifetime probability of approximately 85% of developing breast cancer. Preventive options for these women include surgical interventions such as prophylactic mastectomy and/or oophorectomy, i.e., removal of the breasts and/or ovaries. Therefore, it is important to evaluate the benefits and risks of different screening modalities, to identify additional options for these women.
This Medical Advisory Secretariat review is the second of 2 parts on breast cancer screening, and concentrates on the evaluation of both DM and MRI relative to FM, the standard of care. Part I of this review (March 2006) addressed the effectiveness of screening mammography in 40 to 49 year old average-risk women. The overall objective of the present review is to determine the optimal screening modality based on the evidence.
Evidence Review Strategy
The Medical Advisory Secretariat followed its standard procedures and searched the following electronic databases: Ovid MEDLINE, EMBASE, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and The International Network of Agencies for Health Technology Assessment database. The subject headings and keywords searched included breast cancer, breast neoplasms, mass screening, digital mammography, magnetic resonance imaging. The detailed search strategies can be viewed in Appendix 1.
Included in this review are articles specific to screening and do not include evidence on diagnostic mammography. The search was further restricted to English-language articles published between January 1996 and April 2006. Excluded were case reports, comments, editorials, nonsystematic reviews, and letters.
Digital Mammography: In total, 224 articles specific to DM screening were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 5 health technology assessments (HTAs) (plus 1 update) and 4 articles specific to screening with DM.
Magnetic Resonance Imaging: In total, 193 articles specific to MRI were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 2 HTAs and 7 articles specific to screening with MRI.
The evaluation of the addition of FM to MRI in the screening of women at high risk for breast cancer was also conducted within the context of standard search procedures of the Medical Advisory Secretariat. as outlined above. The subject headings and keywords searched included the concepts of breast cancer, magnetic resonance imaging, mass screening, and high risk/predisposition to breast cancer. The search was further restricted to English-language articles published between September 2007 and January 15, 2010. Case reports, comments, editorials, nonsystematic reviews, and letters were not excluded.
MRI plus mammography: In total, 243 articles specific to MRI plus FM screening were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 2 previous HTAs, and 1 systematic review of 11 paired design studies.
Inclusion Criteria
English-language articles, and English or French-language HTAs published from January 1996 to April 2006, inclusive.
Articles specific to screening of women with no personal history of breast cancer.
Studies in which DM or MRI were compared with FM, and where the specific outcomes of interest were reported.
Randomized controlled trials (RCTs) or paired studies only for assessment of DM.
Prospective, paired studies only for assessment of MRI.
Exclusion Criteria
Studies in which outcomes were not specific to those of interest in this report.
Studies in which women had been previously diagnosed with breast cancer.
Studies in which the intervention (DM or MRI) was not compared with FM.
Studies assessing DM with a sample size of less than 500.
Intervention
Digital mammography.
Magnetic resonance imaging.
Comparator
Screening with film mammography.
Outcomes of Interest
Breast cancer mortality (although no studies were found with such long follow-up).
Sensitivity.
Specificity.
Recall rates.
Summary of Findings
Digital Mammography
There is moderate quality evidence that DM is significantly more sensitive than FM in the screening of asymptomatic women aged less than 50 years, those who are premenopausal or perimenopausal, and those with heterogeneously or extremely dense breast tissue (regardless of age).
It is not known what effect these differences in sensitivity will have on the more important effectiveness outcome measure of breast cancer mortality, as there was no evidence of such an assessment.
Other factors have been set out to promote DM, for example, issues of recall rates and reading and examination times. Our analysis did not show that recall rates were necessarily improved in DM, though examination times were lower than for FM. Other factors including storage and retrieval of screens were not the subject of this analysis.
Magnetic Resonance Imaging
There is moderate quality evidence that the sensitivity of MRI is significantly higher than that of FM in the screening of women at high risk for breast cancer based on genetic or familial factors, regardless of age.
Radiation Risk Review
Cancer Care Ontario conducted a review of the evidence on radiation risk in screening with mammography women at high risk for breast cancer. From this review of recent literature and risk assessment that considered the potential impact of screening mammography in cohorts of women who start screening at an earlier age or who are at increased risk of developing breast cancer due to genetic susceptibility, the following conclusions can be drawn:
For women over 50 years of age, the benefits of mammography greatly outweigh the risk of radiation-induced breast cancer irrespective of the level of a woman’s inherent breast cancer risk.
Annual mammography for women aged 30 – 39 years who carry a breast cancer susceptibility gene or who have a strong family breast cancer history (defined as a first degree relative diagnosed in their thirties) has a favourable benefit:risk ratio. Mammography is estimated to detect 16 to 18 breast cancer cases for every one induced by radiation (Table 1). Initiation of screening at age 35 for this same group would increase the benefit:risk ratio to an even more favourable level of 34-50 cases detected for each one potentially induced.
Mammography for women under 30 years of age has an unfavourable benefit:risk ratio due to the challenges of detecting cancer in younger breasts, the aggressiveness of cancers at this age, the potential for radiation susceptibility at younger ages and a greater cumulative radiation exposure.
Mammography when used in combination with MRI for women who carry a strong breast cancer susceptibility (e.g., BRCA1/2 carriers), which if begun at age 35 and continued for 35 years, may confer greatly improved benefit:risk ratios which were estimated to be about 220 to one.
While there is considerable uncertainty in the risk of radiation-induced breast cancer, the risk expressed in published studies is almost certainly conservative as the radiation dose absorbed by women receiving mammography recently has been substantially reduced by newer technology.
A CCO update of the mammography radiation risk literature for 2008 and 2009 gave rise to one article by Barrington de Gonzales et al. published in 2009 (Barrington de Gonzales et al., 2009, JNCI, vol. 101: 205-209). This article focuses on estimating the risk of radiation-induced breast cancer for mammographic screening of young women at high risk for breast cancer (with BRCA gene mutations). Based on an assumption of a 15% to 25% or less reduction in mortality from mammography in these high risk women, the authors conclude that such a reduction is not substantially greater than the risk of radiation-induced breast cancer mortality when screening before the age of 34 years. That is, there would be no net benefit from annual mammographic screening of BRCA mutation carriers at ages 25-29 years; the net benefit would be zero or small if screening occurs in 30-34 year olds, and there would be some net benefit at age 35 years or older.
The Addition of Mammography to Magnetic Resonance Imaging
The effects of the addition of FM to MRI screening of high risk women was also assessed, with inclusion and exclusion criteria as follows:
Inclusion Criteria
English-language articles and English or French-language HTAs published from September 2007 to January 15, 2010.
Articles specific to screening of women at high risk for breast cancer, regardless of the definition of high risk.
Studies in which accuracy data for the combination of MRI plus FM are available to be compared to that of MRI and FM alone.
RCTs or prospective, paired studies only.
Studies in which women were previously diagnosed with breast cancer were also included.
Exclusion Criteria
Studies in which outcomes were not specific to those of interest in this report.
Studies in which there was insufficient data on the accuracy of MRI plus FM.
Intervention
Both MRI and FM.
Comparators
Screening with MRI alone and FM alone.
Outcomes of Interest
Sensitivity.
Specificity.
Summary of Findings
Magnetic Resonance Imaging Plus Mammography
Moderate GRADE Level Evidence that the sensitivity of MRI plus mammography is significantly higher than that of MRI or FM alone, although the specificity remains either unchanged or decreases in the screening of women at high risk for breast cancer based on genetic/familial factors, regardless of age.
These studies include women at high risk defined as BRCA1/2 or TP53 carriers, first degree relatives of carriers, women with varying degrees of high risk family histories, and/or >20% lifetime risk based on existing risk models. This definition of high risk accounts for approximately 2% of the female adult population in Ontario.
PMCID: PMC3377503  PMID: 23074406
4.  Association between Cutaneous Nevi and Breast Cancer in the Nurses' Health Study: A Prospective Cohort Study 
PLoS Medicine  2014;11(6):e1001659.
Using data from the Nurses' Health Study, Jiali Han and colleagues examine the association between number of cutaneous nevi and the risk for breast cancer.
Please see later in the article for the Editors' Summary
Background
Cutaneous nevi are suggested to be hormone-related. We hypothesized that the number of cutaneous nevi might be a phenotypic marker of plasma hormone levels and predict subsequent breast cancer risk.
Methods and Findings
We followed 74,523 female nurses for 24 y (1986–2010) in the Nurses' Health Study and estimate the relative risk of breast cancer according to the number of cutaneous nevi. We adjusted for the known breast cancer risk factors in the models. During follow-up, a total of 5,483 invasive breast cancer cases were diagnosed. Compared to women with no nevi, women with more cutaneous nevi had higher risks of breast cancer (multivariable-adjusted hazard ratio, 1.04, 95% confidence interval [CI], 0.98–1.10 for 1–5 nevi; 1.15, 95% CI, 1.00–1.31 for 6–14 nevi, and 1.35, 95% CI, 1.04–1.74 for 15 or more nevi; p for continuous trend = 0.003). Over 24 y of follow-up, the absolute risk of developing breast cancer increased from 8.48% for women without cutaneous nevi to 8.82% (95% CI, 8.31%–9.33%) for women with 1–5 nevi, 9.75% (95% CI, 8.48%–11.11%) for women with 6–14 nevi, and 11.4% (95% CI, 8.82%–14.76%) for women with 15 or more nevi. The number of cutaneous nevi was associated with increased risk of breast cancer only among estrogen receptor (ER)–positive tumors (multivariable-adjusted hazard ratio per five nevi, 1.09, 95% CI, 1.02–1.16 for ER+/progesterone receptor [PR]–positive tumors; 1.08, 95% CI, 0.94–1.24 for ER+/PR− tumors; and 0.99, 95% CI, 0.86–1.15 for ER−/PR− tumors). Additionally, we tested plasma hormone levels according to the number of cutaneous nevi among a subgroup of postmenopausal women without postmenopausal hormone use (n = 611). Postmenopausal women with six or more nevi had a 45.5% higher level of free estradiol and a 47.4% higher level of free testosterone compared to those with no nevi (p for trend = 0.001 for both). Among a subgroup of 362 breast cancer cases and 611 matched controls with plasma hormone measurements, the multivariable-adjusted odds ratio for every five nevi attenuated from 1.25 (95% CI, 0.89–1.74) to 1.16 (95% CI, 0.83–1.64) after adjusting for plasma hormone levels. Key limitations in this study are that cutaneous nevi were self-counted in our cohort and that the study was conducted in white individuals, and thus the findings do not necessarily apply to other populations.
Conclusions
Our results suggest that the number of cutaneous nevi may reflect plasma hormone levels and predict breast cancer risk independently of previously known factors.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
One woman in eight will develop breast cancer during her lifetime. Breast cancer begins when cells in the breast acquire genetic changes that allow them to divide uncontrollably (which leads to the formation of a lump in the breast) and to move around the body (metastasize). The treatment of breast cancer, which is diagnosed using mammography (a breast X-ray) or manual breast examination and biopsy, usually involves surgery to remove the lump, or the whole breast (mastectomy) if the cancer has started to metastasize. After surgery, women often receive chemotherapy or radiotherapy to kill any remaining cancer cells and may also be given drugs that block the action of estrogen and progesterone, female sex hormones that stimulate the growth of some breast cancer cells. Globally, half a million women die from breast cancer each year. However, in developed countries, nearly 90% of women affected by breast cancer are still alive five years after diagnosis.
Why Was This Study Done?
Several sex hormone–related factors affect breast cancer risk, including at what age a woman has her first child (pregnancy alters sex hormone levels) and her age at menopause, when estrogen levels normally drop. Moreover, postmenopausal women with high circulating levels of estrogen and testosterone (a male sex hormone) have an increased breast cancer risk. Interestingly, moles (nevi)—dark skin blemishes that are a risk factor for the development of melanoma, a type of skin cancer—often darken or enlarge during pregnancy. Might the number of nevi be a marker of hormone levels, and could nevi counts therefore be used to predict an individual's risk of breast cancer? In this prospective cohort study, the researchers look for an association between number of nevi and breast cancer risk among participants in the US Nurses' Health Study (NHS). A prospective cohort study enrolls a group of people, determines their baseline characteristics, and follows them over time to see which characteristics are associated with the development of certain diseases. The NHS, which enrolled 121,700 female nurses aged 30–55 years in 1976, is studying risk factors for cancer and other chronic diseases in women.
What Did the Researchers Do and Find?
In 1986, nearly 75,000 NHS participants (all of whom were white) reported how many nevi they had on their left arm. Over the next 24 years, 5,483 invasive breast cancers were diagnosed in these women. Compared to women with no nevi, women with increasing numbers of nevi had a higher risk of breast cancer after adjustment for known breast cancer risk factors. Specifically, among women with 1–5 nevi, the hazard ratio (HR) for breast cancer was 1.04, whereas among women with 15 or more nevi the HR was 1.35. An HR compares how often a particular event occurs in two groups with different characteristics; an HR greater than one indicates that a specific characteristic is associated with an increased risk of the event. Over 24 years of follow-up, the absolute risk of developing breast cancer was 8.48% in women with no nevi but 11.4% for women with 15 or more nevi. Notably, postmenopausal women with six or more nevi had higher blood levels of estrogen and testosterone than women with no nevi. Finally, in a subgroup analysis, the association between number of nevi and breast cancer risk disappeared after adjustment for hormone levels.
What Do These Findings Mean?
These findings support the hypothesis that the number of nevi reflects sex hormone levels in women and may predict breast cancer risk. Notably, they show that the association between breast cancer risk and nevus number was independent of known risk factors for breast cancer, and that the risk of breast cancer increased with the number of nevi in a dose-dependent manner. These findings also suggest that a hormonal mechanism underlies the association between nevus number and breast cancer risk. Because this study involved only white participants, these findings may not apply to non-white women. Moreover, the use of self-reported data on nevus numbers may affect the accuracy of these findings. Finally, because this study is observational, these findings are insufficient to support any changes in clinical recommendations for breast cancer screening or diagnosis. Nevertheless, these data and those in an independent PLOS Medicine Research Article by Kvaskoff et al. support the need for further investigation of the association between nevi and breast cancer risk and of the mechanisms underlying this relationship.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001659.
An independent PLOS Medicine Research Article by Kvaskoff et al. also investigates the relationship between nevi and breast cancer risk
The US National Cancer Institute provides comprehensive information about cancer (in English and Spanish), including detailed information for patients and professionals about breast cancer; it also has a fact sheet on moles
Cancer Research UK, a not-for profit organization, provides information about cancer, including detailed information on breast cancer
The UK National Health Service Choices website has information and personal stories about breast cancer; the not-for profit organization Healthtalkonline also provides personal stories about dealing with breast cancer
More information about the Nurses' Health Study is available
doi:10.1371/journal.pmed.1001659
PMCID: PMC4051600  PMID: 24915186
5.  Risk Prediction for Breast, Endometrial, and Ovarian Cancer in White Women Aged 50 y or Older: Derivation and Validation from Population-Based Cohort Studies 
PLoS Medicine  2013;10(7):e1001492.
Ruth Pfeiffer and colleagues describe models to calculate absolute risks for breast, endometrial, and ovarian cancers for white, non-Hispanic women over 50 years old using easily obtainable risk factors.
Please see later in the article for the Editors' Summary
Background
Breast, endometrial, and ovarian cancers share some hormonal and epidemiologic risk factors. While several models predict absolute risk of breast cancer, there are few models for ovarian cancer in the general population, and none for endometrial cancer.
Methods and Findings
Using data on white, non-Hispanic women aged 50+ y from two large population-based cohorts (the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [PLCO] and the National Institutes of Health–AARP Diet and Health Study [NIH-AARP]), we estimated relative and attributable risks and combined them with age-specific US-population incidence and competing mortality rates. All models included parity. The breast cancer model additionally included estrogen and progestin menopausal hormone therapy (MHT) use, other MHT use, age at first live birth, menopausal status, age at menopause, family history of breast or ovarian cancer, benign breast disease/biopsies, alcohol consumption, and body mass index (BMI); the endometrial model included menopausal status, age at menopause, BMI, smoking, oral contraceptive use, MHT use, and an interaction term between BMI and MHT use; the ovarian model included oral contraceptive use, MHT use, and family history or breast or ovarian cancer. In independent validation data (Nurses' Health Study cohort) the breast and ovarian cancer models were well calibrated; expected to observed cancer ratios were 1.00 (95% confidence interval [CI]: 0.96–1.04) for breast cancer and 1.08 (95% CI: 0.97–1.19) for ovarian cancer. The number of endometrial cancers was significantly overestimated, expected/observed = 1.20 (95% CI: 1.11–1.29). The areas under the receiver operating characteristic curves (AUCs; discriminatory power) were 0.58 (95% CI: 0.57–0.59), 0.59 (95% CI: 0.56–0.63), and 0.68 (95% CI: 0.66–0.70) for the breast, ovarian, and endometrial models, respectively.
Conclusions
These models predict absolute risks for breast, endometrial, and ovarian cancers from easily obtainable risk factors and may assist in clinical decision-making. Limitations are the modest discriminatory ability of the breast and ovarian models and that these models may not generalize to women of other races.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In 2008, just three types of cancer accounted for 10% of global cancer-related deaths. That year, about 460,000 women died from breast cancer (the most frequently diagnosed cancer among women and the fifth most common cause of cancer-related death). Another 140,000 women died from ovarian cancer, and 74,000 died from endometrial (womb) cancer (the 14th and 20th most common causes of cancer-related death, respectively). Although these three cancers originate in different tissues, they nevertheless share many risk factors. For example, current age, age at menarche (first period), and parity (the number of children a woman has had) are all strongly associated with breast, ovarian, and endometrial cancer risk. Because these cancers share many hormonal and epidemiological risk factors, a woman with a high breast cancer risk is also likely to have an above-average risk of developing ovarian or endometrial cancer.
Why Was This Study Done?
Several statistical models (for example, the Breast Cancer Risk Assessment Tool) have been developed that estimate a woman's absolute risk (probability) of developing breast cancer over the next few years or over her lifetime. Absolute risk prediction models are useful in the design of cancer prevention trials and can also help women make informed decisions about cancer prevention and treatment options. For example, a woman at high risk of breast cancer might decide to take tamoxifen for breast cancer prevention, but ideally she needs to know her absolute endometrial cancer risk before doing so because tamoxifen increases the risk of this cancer. Similarly, knowledge of her ovarian cancer risk might influence a woman's decision regarding prophylactic removal of her ovaries to reduce her breast cancer risk. There are few absolute risk prediction models for ovarian cancer, and none for endometrial cancer, so here the researchers develop models to predict the risk of these cancers and of breast cancer.
What Did the Researchers Do and Find?
Absolute risk prediction models are constructed by combining estimates for risk factors from cohorts with population-based incidence rates from cancer registries. Models are validated in an independent cohort by testing their ability to identify people with the disease in an independent cohort and their ability to predict the observed numbers of incident cases. The researchers used data on white, non-Hispanic women aged 50 years or older that were collected during two large prospective US cohort studies of cancer screening and of diet and health, and US cancer incidence and mortality rates provided by the Surveillance, Epidemiology, and End Results Program to build their models. The models all included parity as a risk factor, as well as other factors. The model for endometrial cancer, for example, also included menopausal status, age at menopause, body mass index (an indicator of the amount of body fat), oral contraceptive use, menopausal hormone therapy use, and an interaction term between menopausal hormone therapy use and body mass index. Individual women's risk for endometrial cancer calculated using this model ranged from 1.22% to 17.8% over the next 20 years depending on their exposure to various risk factors. Validation of the models using data from the US Nurses' Health Study indicated that the endometrial cancer model overestimated the risk of endometrial cancer but that the breast and ovarian cancer models were well calibrated—the predicted and observed risks for these cancers in the validation cohort agreed closely. Finally, the discriminatory power of the models (a measure of how well a model separates people who have a disease from people who do not have the disease) was modest for the breast and ovarian cancer models but somewhat better for the endometrial cancer model.
What Do These Findings Mean?
These findings show that breast, ovarian, and endometrial cancer can all be predicted using information on known risk factors for these cancers that is easily obtainable. Because these models were constructed and validated using data from white, non-Hispanic women aged 50 years or older, they may not accurately predict absolute risk for these cancers for women of other races or ethnicities. Moreover, the modest discriminatory power of the breast and ovarian cancer models means they cannot be used to decide which women should be routinely screened for these cancers. Importantly, however, these well-calibrated models should provide realistic information about an individual's risk of developing breast, ovarian, or endometrial cancer that can be used in clinical decision-making and that may assist in the identification of potential participants for research studies.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001492.
This study is further discussed in a PLOS Medicine Perspective by Lars Holmberg and Andrew Vickers
The US National Cancer Institute provides comprehensive information about cancer (in English and Spanish), including detailed information about breast cancer, ovarian cancer, and endometrial cancer;
Information on the Breast Cancer Risk Assessment Tool, the Surveillance, Epidemiology, and End Results Program, and on the prospective cohort study of screening and the diet and health study that provided the data used to build the models is also available on the NCI site
Cancer Research UK, a not-for-profit organization, provides information about cancer, including detailed information on breast cancer, ovarian cancer, and endometrial cancer
The UK National Health Service Choices website has information and personal stories about breast cancer, ovarian cancer, and endometrial cancer; the not-for-profit organization Healthtalkonline also provides personal stories about dealing with breast cancer and ovarian cancer
doi:10.1371/journal.pmed.1001492
PMCID: PMC3728034  PMID: 23935463
6.  IHC for Her2 with CBE356 antibody is a more accurate predictor of Her2 gene amplification by FISH than HercepTest™ in breast carcinoma 
Journal of Clinical Pathology  2005;58(10):1086-1090.
Background: Her2 (c-erbB-2/neu) overexpression in breast carcinoma predicts response to the anti-Her2 monoclonal antibody, trastuzumab, and is associated with a poor prognosis. When considering patients for trastuzumab treatment, Her2 protein expression is measured by imunohistochemistry (IHC) and, where staining is equivocal, by fluorescence in situ hybridisation (FISH) detection of Her2 gene amplification.
Aims: To compare IHC using CBE356 with IHC using the Food and Drug Administration approved HercepTest™.
Methods: CBE356 and HercepTest were analysed using 167 FISH characterised breast carcinomas. Immunohistochemical expression of Her2 was measured semiquantitatively. Sensitivity, specificity, predictive values, and overall accuracy were calculated for both IHC methods using gene amplification by FISH as the end point, and IHC and FISH assays were tested in Kaplan–Meier survival analysis.
Results: The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CBE356 positive (2+ and 3+) cases were 94%, 89%, 95%, 84%, and 97%, respectively, and of HercepTest positive (2+ and 3+) cases were 91%, 66%, 98%, 92%, and 91%, respectively. A positive result with CBE356, HercepTest, or FISH was associated with significantly decreased overall survival (log rank p = 0.005, p = 0.0017, and p = 0.0005, respectively).
Conclusions: Positive IHC staining for Her2 using CBE356 is 3% more accurate and 23% more sensitive at predicting Her2 gene amplification by FISH than positive staining with HercepTest. Negative IHC using CBE356 antibody is 6% more likely to represent a truly negative result than negative staining with HercepTest. Overall, CBE356 was a more accurate predictor of Her2 gene amplification by FISH than HercepTest.
doi:10.1136/jcp.2004.021576
PMCID: PMC1770743  PMID: 16189156
CBE356; immunohistochemistry; Her expression; breast carcinoma
7.  Practical Applications for Clinical Breast Examination (CBE) and Breast Self-Examination (BSE) in Screening and Early Detection of Breast Cancer* 
Breast Care  2008;3(1):17-20.
Summary
The background and preliminary results in terms of stage distribution are given for a trial of Clinical Breast Examination and the teaching of Breast Self-Examination in Cairo, Egypt. A stage shift towards early diagnosis appears to have been achieved. This has encouraged the development of similar projects in other middle income developing countries.
doi:10.1159/000113934
PMCID: PMC2931013  PMID: 20824015
Breast cancer; Screening; breast examination, clinical; Breast self-examination
8.  Association between Melanocytic Nevi and Risk of Breast Diseases: The French E3N Prospective Cohort 
PLoS Medicine  2014;11(6):e1001660.
Using data from the French E3N prospective cohort, Marina Kvaskoff and colleagues examine the association between number of cutaneous nevi and the risk for breast cancer.
Please see later in the article for the Editors' Summary
Background
While melanocytic nevi have been associated with genetic factors and childhood sun exposure, several observations also suggest a potential hormonal influence on nevi. To test the hypothesis that nevi are associated with breast tumor risk, we explored the relationships between number of nevi and benign and malignant breast disease risk.
Methods and Findings
We prospectively analyzed data from E3N, a cohort of French women aged 40–65 y at inclusion in 1990. Number of nevi was collected at inclusion. Hazard ratios (HRs) for breast cancer and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. Associations of number of nevi with personal history of benign breast disease (BBD) and family history of breast cancer were estimated using logistic regression. Over the period 15 June 1990–15 June 2008, 5,956 incident breast cancer cases (including 5,245 invasive tumors) were ascertained among 89,902 women. In models adjusted for age, education, and known breast cancer risk factors, women with “very many” nevi had a significantly higher breast cancer risk (HR = 1.13, 95% CI = 1.01–1.27 versus “none”; ptrend = 0.04), although significance was lost after adjustment for personal history of BBD or family history of breast cancer. The 10-y absolute risk of invasive breast cancer increased from 3,749 per 100,000 women without nevi to 4,124 (95% CI = 3,674–4,649) per 100,000 women with “very many” nevi. The association was restricted to premenopausal women (HR = 1.40, ptrend = 0.01), even after full adjustment (HR = 1.34, ptrend = 0.03; phomogeneity = 0.04), but did not differ according to breast cancer type or hormone receptor status. In addition, we observed significantly positive dose–response relationships between number of nevi and history of biopsy-confirmed BBD (n = 5,169; ptrend<0.0001) and family history of breast cancer in first-degree relatives (n = 7,472; ptrend = 0.0003). The main limitations of our study include self-report of number of nevi using a qualitative scale, and self-reported history of biopsied BBD.
Conclusions
Our findings suggest associations between number of nevi and the risk of premenopausal breast cancer, BBD, and family history of breast cancer. More research is warranted to elucidate these relationships and to understand their underlying mechanisms.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In 2012, nearly 1.7 million women worldwide discovered they had breast cancer, and about half a million women died from the disease. Breast cancer begins when cells in the breast acquire genetic changes that allow them to divide uncontrollably and to move around the body (metastasize). Uncontrolled cell division leads to the formation of a lump that can be detected by mammography (a breast X-ray) or by manual breast examination. Breast cancer is treated by surgical removal of the lump, or, if the cancer has started to spread, by removal of the whole breast (mastectomy). Surgery is usually followed by radiotherapy or chemotherapy to kill any remaining cancer cells. Because the female sex hormones estrogen and progesterone stimulate the growth of some tumors, drugs that block hormone receptors are also used to treat receptor-positive breast cancer. Nowadays, the prognosis (outlook) for women with breast cancer is good, and in developed countries, nearly 90% of affected women are still alive five years after diagnosis.
Why Was This Study Done?
Several hormone-related factors affect a woman's chances of developing breast cancer. For example, women who have no children or who have them late in life have a higher breast cancer risk than women who have several children when they are young because pregnancy alters sex hormone levels. Interestingly, the development of moles (nevi)—dark skin blemishes that are risk factors for the development of melanoma, a type of skin cancer—may also be affected by estrogen and progesterone. Thus, the number of nevi might be a marker of blood hormone levels and might predict breast cancer risk. In this prospective cohort study, the researchers test this hypothesis by investigating the association between how many moles a woman has and her breast cancer risk. A prospective cohort study enrolls a group (cohort) of people, determines their baseline characteristics, and follows them over time to see which characteristics are associated with the development of specific diseases.
What Did the Researchers Do and Find?
In 1990, the E3N prospective cohort study enrolled nearly 100,000 French women (mainly school teachers) aged 40–65 years to investigate cancer risk factors. The women completed a baseline questionnaire about their lifestyle and medical history, and regular follow-up questionnaires that asked about cancer occurrence. In the initial questionnaire, the women indicated whether they had no, a few, many, or very many moles. Between 1990 and 2008, nearly 6,000 women in the cohort developed breast cancer. Using statistical methods to calculate hazard ratios (an “HR” compares how often a particular event happens in two groups with different characteristics; an HR greater than one indicates that a specific characteristic is associated with an increased risk of the event), the researchers report that women with “very many” nevi had a significantly higher breast cancer risk (a higher risk that was unlikely to have occurred by chance) than women with no nevi. Specifically, the age-adjusted HR for breast cancer among women with “very many” nevi compared to women with no nevi was 1.17. After adjustment for a personal history of benign (noncancerous) breast disease and a family history of breast cancer (two established risk factors for breast cancer), the association between nevi and breast cancer risk among the whole cohort became nonsignificant. Notably, however, the association among only premenopausal women remained significant after full adjustment (HR = 1.34), which corresponded to an increase in ten-year absolute risk of invasive breast cancer from 2,515 per 100,000 women with no nevi to 3,370 per 100,000 women with “very many” nevi.
What Do These Findings Mean?
These findings suggest that among premenopausal women there is a modest association between nevi number and breast cancer risk. This noncausal relationship may indicate that nevi and breast diseases are affected in similar ways by hormones or share common genetic factors, but the accuracy of these findings may be limited by aspects of the study design. For example, self-report of nevi numbers using a qualitative scale may have introduced some inaccuracies into the estimates of the association between nevi number and breast cancer risk. Most importantly, these findings are insufficient to support the use of nevi counts in breast cancer screening or diagnosis. Rather, together with the findings reported by Zhang et al. in an independent PLOS Medicine Research Article, they suggest that further studies into the biological mechanisms underlying the relationship between nevi and breast cancer and the association itself should be undertaken.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001660.
This study is further discussed in a PLOS Medicine Perspective by Fuhrman and Cardenas
An independent PLOS Medicine Research Article by Zhang et al. also investigates the relationship between nevi number and breast cancer risk
The US National Cancer Institute provides comprehensive information about cancer (in English and Spanish), including detailed information for patients and professionals about breast cancer; it also has a fact sheet on moles
Cancer Research UK, a not-for profit organization, provides information about cancer, including detailed information on breast cancer
The UK National Health Service Choices website has information and personal stories about breast cancer; the not-for profit organization Healthtalkonline also provides personal stories about dealing with breast cancer
More information about the E3N prospective cohort study is available; detailed information is available in French
doi:10.1371/journal.pmed.1001660
PMCID: PMC4051602  PMID: 24915306
9.  The BARD1 Cys557Ser Variant and Breast Cancer Risk in Iceland 
PLoS Medicine  2006;3(7):e217.
Background
Most, if not all, of the cellular functions of the BRCA1 protein are mediated through heterodimeric complexes composed of BRCA1 and a related protein, BARD1. Some breast-cancer-associated BRCA1 missense mutations disrupt the function of the BRCA1/BARD1 complex. It is therefore pertinent to determine whether variants of BARD1 confer susceptibility to breast cancer. Recently, a missense BARD1 variant, Cys557Ser, was reported to be at increased frequencies in breast cancer families. We investigated the role of the BARD1 Cys557Ser variant in a population-based cohort of 1,090 Icelandic patients with invasive breast cancer and 703 controls. We then used a computerized genealogy of the Icelandic population to study the relationships between the Cys557Ser variant and familial clustering of breast cancer.
Methods and Findings
The Cys557Ser allele was present at a frequency of 0.028 in patients with invasive breast cancer and 0.016 in controls (odds ratio [OR] = 1.82, 95% confidence interval [CI] 1.11–3.01, p = 0.014). The alleleic frequency was 0.037 in a high-predisposition group of cases defined by having a family history of breast cancer, early onset of breast cancer, or multiple primary breast cancers (OR = 2.41, 95% CI 1.22–4.75, p = 0.015). Carriers of the common Icelandic BRCA2 999del5 mutation were found to have their risk of breast cancer further increased if they also carried the BARD1 variant: the frequency of the BARD1 variant allele was 0.047 (OR = 3.11, 95% CI 1.16–8.40, p = 0.046) in 999del5 carriers with breast cancer. This suggests that the lifetime probability of a BARD1 Cys557Ser/BRCA2 999del5 double carrier developing breast cancer could approach certainty. Cys557Ser carriers, with or without the BRCA2 mutation, had an increased risk of subsequent primary breast tumors after the first breast cancer diagnosis compared to non-carriers. Lobular and medullary breast carcinomas were overrepresented amongst Cys557Ser carriers. We found that an excess of ancestors of contemporary carriers lived in a single county in the southeast of Iceland and that all carriers shared a SNP haplotype, which is suggestive of a founder event. Cys557Ser was found on the same SNP haplotype background in the HapMap Project CEPH sample of Utah residents.
Conclusions
Our findings suggest that BARD1 Cys557Ser is an ancient variant that confers risk of single and multiple primary breast cancers, and this risk extends to carriers of the BRCA2 999del5 mutation.
Editors' Summary
Background.
About 13% of women (one in eight women) will develop breast cancer during their lifetime, but many factors affect the likelihood of any individual woman developing this disease, for example, whether she has had children and at what age, when she started and stopped her periods, and her exposure to certain chemicals or radiation. She may also have inherited a defective gene that affects her risk of developing breast cancer. Some 5%–10% of all breast cancers are familial, or inherited. In 20% of these cases, the gene that is defective is BRCA1 or BRCA2. Inheriting a defective copy of one of these genes greatly increases a woman's risk of developing breast cancer, while researchers think that the other inherited genes that predispose to breast cancer—most of which have not been identified yet—have a much weaker effect. These are described as low-penetrance genes. Inheriting one such gene only slightly increases breast cancer risk; a woman has to inherit several to increase her lifetime risk of cancer significantly.
Why Was This Study Done?
It is important to identify these additional predisposing gene variants because they might provide insights into why breast cancer develops, how to prevent it, and how to treat it. To find low-penetrance genes, researchers do case–control association studies. They find a large group of women with breast cancer (cases) and a similar group of women without cancer (controls), and examine how often a specific gene variant occurs in the two groups. If the variant is found more often in the cases than in the controls, it might be a variant that increases a woman's risk of developing breast cancer.
What Did the Researchers Do and Find?
The researchers involved in this study recruited Icelandic women who had had breast cancer and unaffected women, and looked for a specific variant—the Cys557Ser allele—of a gene called BARD1. They chose BARD1 because the protein it encodes interacts with the protein encoded by BRCA1. Because defects in BRCA1 increase the risk of breast cancer, defects in an interacting protein might have a similar effect. In addition, the Cys557Ser allele has been implicated in breast cancer in other studies. The researchers found that the Cys557Ser allele was nearly twice as common in women with breast cancer as in control women. It was also more common (but not by much) in women who had a family history of breast cancer or who had developed breast cancer more than once. And having the Cys557Ser allele seemed to increase the already high risk of breast cancer in women who had a BRCA2 variant (known as BRCA2 999del5) that accounts for 40% of inherited breast cancer risk in Iceland.
What Do These Findings Mean?
These results indicate that inheriting the BARD1 Cys557Ser allele increases a woman's breast cancer risk but that she is unlikely to have a family history of the disease. Because carrying the Cys557Ser allele only slightly increases a woman's risk of breast cancer, for most women there is no clinical reason to test for this variant. Eventually, when all the low-penetrance genes that contribute to breast cancer risk have been identified, it might be helpful to screen women for the full set to determine whether they are at high risk of developing breast cancer. This will not happen for many years, however, since there might be tens or hundreds of these genes. For women who carry BRCA2 999del5, the situation might be different. It might be worth testing these women for the BARD1 Cys557Ser allele, the researchers explain, because the lifetime probability of developing breast cancer in women carrying both variants might approach 100%. This finding has clinical implications in terms of counseling and monitoring, as does the observation that Cys557Ser carriers have an increased risk of a second, independent breast cancer compared to non-carriers. However, all these findings need to be confirmed in other groups of patients before anyone is routinely tested for the BARD1 Cys557Ser allele.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030217.
• MedlinePlus pages about breast cancer
• Information on breast cancer from the United States National Cancer Institute
• Information on inherited breast cancer from the United States National Human Genome Research Institute
• United States National Cancer Institute information on genetic testing for BRCA1 and BRCA2 variants
• GeneTests pages on the involvement of BRCA1 and BRCA2 in hereditary breast and ovarian cancer
• Cancer Research UK's page on breast cancer statistics
In a population-based cohort of 1090 Icelandic patients, a Cys557Ser missense variant of the BARD1 gene, which interacts with BRCA1, increased the risk of single and multiple primary breast cancers.
doi:10.1371/journal.pmed.0030217
PMCID: PMC1479388  PMID: 16768547
10.  Birth Size and Breast Cancer Risk: Re-analysis of Individual Participant Data from 32 Studies 
PLoS Medicine  2008;5(9):e193.
Background
Birth size, perhaps a proxy for prenatal environment, might be a correlate of subsequent breast cancer risk, but findings from epidemiological studies have been inconsistent. We re-analysed individual participant data from published and unpublished studies to obtain more precise estimates of the magnitude and shape of the birth size–breast cancer association.
Methods and Findings
Studies were identified through computer-assisted and manual searches, and personal communication with investigators. Individual participant data from 32 studies, comprising 22,058 breast cancer cases, were obtained. Random effect models were used, if appropriate, to combine study-specific estimates of effect. Birth weight was positively associated with breast cancer risk in studies based on birth records (pooled relative risk [RR] per one standard deviation [SD] [= 0.5 kg] increment in birth weight: 1.06; 95% confidence interval [CI] 1.02–1.09) and parental recall when the participants were children (1.02; 95% CI 0.99–1.05), but not in those based on adult self-reports, or maternal recall during the woman's adulthood (0.98; 95% CI 0.95–1.01) (p for heterogeneity between data sources = 0.003). Relative to women who weighed 3.000–3.499 kg, the risk was 0.96 (CI 0.80–1.16) in those who weighed < 2.500 kg, and 1.12 (95% CI 1.00–1.25) in those who weighed ≥ 4.000 kg (p for linear trend = 0.001) in birth record data. Birth length and head circumference from birth records were also positively associated with breast cancer risk (pooled RR per one SD increment: 1.06 [95% CI 1.03–1.10] and 1.09 [95% CI 1.03–1.15], respectively). Simultaneous adjustment for these three birth size variables showed that length was the strongest independent predictor of risk. The birth size effects did not appear to be confounded or mediated by established breast cancer risk factors and were not modified by age or menopausal status. The cumulative incidence of breast cancer per 100 women by age 80 y in the study populations was estimated to be 10.0, 10.0, 10.4, and 11.5 in those who were, respectively, in the bottom, second, third, and top fourths of the birth length distribution.
Conclusions
This pooled analysis of individual participant data is consistent with birth size, and in particular birth length, being an independent correlate of breast cancer risk in adulthood.
Editors' Summary
Background.
Last year, more than one million women discovered that they had breast cancer. In the US, nearly 200,000 women will face the same diagnosis this year and 40,000 will die because of breast cancer. Put another way, about one in eight US women will have breast cancer during her lifetime. Like all cancers, breast cancer begins when cells acquire genetic changes that allow them to divide uncontrollably and to move around the body (metastasize). This uncontrolled division leads to the formation of a lump that can be detected by mammography (a breast X-ray) or by manual examination of the breasts. Breast cancer is treated by surgical removal of the lump or, if the cancer has started to spread, by removal of the whole breast (mastectomy). Surgery is usually followed by radiotherapy, chemotherapy, and other treatments designed to kill any remaining cancer cells. Unlike some cancers, the outlook for women with breast cancer is good. In the US, for example, nearly 90% of affected women are still alive five years after their diagnosis.
Why Was This Study Done?
Scientists have identified several factors that increase a woman's risk of developing breast cancer by comparing the characteristics of populations of women with and without breast cancer. Well-established risk factors include increasing age, not having children, and having a late menopause, but another potential risk factor for breast cancer is birth size. A baby's weight, length, and head circumference at birth (three related measures of birth size) depend on the levels of hormones (including estrogen, a hormone that often affects breast cancer growth) and other biological factors to which the baby is exposed during pregnancy—its prenatal environment. The idea that prenatal environment might also affect breast cancer risk in later life was first proposed in 1990, but the findings of studies that have tried to investigate this possibility have been inconsistent. Here, the researchers re-analyze individual participant data from a large number of studies into women's health conducted in Europe, Northern America, and China to get more precise information about the association between birth size and breast cancer risk.
What Did the Researchers Do and Find?
The researchers identified 32 published and unpublished studies that had collected information on birth size and on the occurrence of breast cancer. They then obtained the individual participant data from these studies, which involved more than 22,000 women who had developed breast cancer and more than 600,000 women who had not. Their analyses of these data show that birth weight was positively associated with breast cancer risk in those studies where this measurement was recorded at birth or based on parental recall during the study participant's childhood (but not in those studies in which birth weight was self-reported or maternally recalled during the participant's adulthood). For example, women with recorded birth weights of more than 4 kg or more had a 12% higher chance of developing breast cancer than women who weighed 3–3.5 kg at birth. Birth length and head circumference were also positively associated with breast cancer risk, but birth length was the strongest single predictor of risk. Finally, the amount by which birth size affected breast cancer risk was not affected by allowing for other established risk factors.
What Do These Findings Mean?
These findings provide strong evidence that birth size—in particular, birth length—is a marker of a woman's breast cancer risk in adulthood although the mechanisms underlying this association are unclear. The researchers note that the observed effect of birth size on breast cancer risk is of a similar magnitude to that of other more established risk factors and estimate that 5% of all breast cancers in developed countries could be caused by a high birth size. Because practically all the studies included in this pooled analysis were done in developed countries, these findings may not hold for developing countries. Further investigations into how the prenatal environment may affect breast cancer risk might identify new ways to prevent this increasingly common cancer.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050193.
This study is further discussed in a PLoS Medicine Perspective by Trichopoulos and Lagiou
The US National Cancer Institute provides detailed information for patients and health professionals on all aspects of breast cancer, including information on risk factors for breast cancer (in English and Spanish)
The MedlinePlus Encyclopedia provides information for patients about breast cancer; Medline Plus also provides links to many other breast cancer resources (in English and Spanish)
The UK charity Cancerbackup also provides detailed information about breast cancer
Cancer Research UK is the UK's leading charity dedicated to cancer research
doi:10.1371/journal.pmed.0050193
PMCID: PMC2553821  PMID: 18828667
11.  BRCA1 and BRCA2 mutations in central and southern Italian patients 
Breast Cancer Research : BCR  2000;2(4):307-310.
Protein truncation test (PTT) and single-strand conformation polymorphism (SSCP) assay were used to scan the BRCA1 and BRCA2 genes in 136 unrelated Italian breast/ovarian cancer patients. In the sample tested, BRCA1 and BRCA2 equally contributed to site-specific breast cancer patients who reported one to two breast cancer-affected first-/ second-degree relative(s) or who were diagnosed before age 40 years in the absence of a family history of breast/ovarian cancer. BRCA1 and BRCA2 mutations were mostly found in patients with disease diagnosis before and after age 50 years, respectively. Moreover, in cases with familial clustering of site-specific breast cancer, BRCA1 mostly accounted for tumours diagnosed before age 40 years and BRCA2 for tumours diagnosed after age 50 years. The BRCA1 and BRCA2 mutation spectrum was consistent with a lack of significant founder effects in the sample of patients studied.
Introduction:
Germline BRCA1 and BRCA2 mutations account for most hereditary breast/ovarian cancers and are associated with male breast cancer. Furthermore, constitutional mutations in these genes may occur in breast/ovarian cancer patients that do not meet stringent criteria of autosomal-dominant predisposition. The relevance of BRCA1 and BRCA2 mutations in such patients is still debated.
Objectives:
We sought to determine the impact of BRCA1 and BRCA2 mutations in a population of patients from central and southern Italy. We analyzed the BRCA1 and BRCA2 coding regions in 136 unrelated probands: 117 females with breast/ovarian cancer and 19 males with breast cancer. This population of patients was mostly representative of cases who are at risk for hereditary susceptibility, but who do not meet stringent criteria of autosomal-dominant predisposition.
Methods:
Probands, subclassified as follows, were consecutively recruited depending on informed consent from patients attending breast cancer clinics in Rome and Naples. Selection criteria for females were as follows: breast cancer with breast cancer family history [one to two first-/second-degree relative(s), n = 55]; breast cancer diagnosed before age 40 years (no breast/ovarian cancer family history, n = 28); bilateral breast cancer (regardless of age and family history, n =10); breast cancer associated with gastrointestinal, pancreatic or uterine cancers [synchronous/metachronous or in first-degree relative(s), n = 9]; breast or ovarian cancer with family history of breast-ovarian/ovarian cancer (at least 1 first-/ second-degree relative, n = 10); and ovarian cancer with no breast/ovarian cancer family history (n = 5). Males with breast cancer were recruited regardless of age and family history. BRCA1 exon 11 and BRCA2 exons 10 and 11 were screened by PTT. Coding BRCA1 exons 2, 3, 5-10 and 12-24 and BRCA2 exons 2-9 and 12-27 were screened by SSCP. Primers are listed in Table 1. In 27 cases, analyzed by PTT along the entire BRCA1 coding sequence, BRCA1 SSCP analysis was limited to exons 2, 5, 20 and 24. Mutations were verified by sequence analysis on two independent blood samples.
Results:
Deleterious germline BRCA1/BRCA2 mutations were detected in 11 out of 136 cases (8%). Only three BRCA2 mutations were novel. One BRCA2 mutation recurred in two unrelated probands. Table 2 shows the mutations and data concerning carriers and their families. Table 3 shows correlations between BRCA1/BRCA2 mutations and sex, age at disease diagnosis and familial clustering of breast/ovarian cancer in the total patient population. Table 4 shows the proportions of BRCA1 and BRCA2 mutations in females with site-specific breast and breast-ovarian/ovarian cancer. Table 5 shows the frequency of BRCA1/BRCA2 mutations in males. BRCA1 and BRCA2 mutations, respectively, accounted for four out of 68 (6%) and one out of 68 (1%) cases diagnosed before age 50 years, and for one out of 68 (1%) and five out of 68 (7%) cases diagnosed after age 50 years. BRCA1 mutations were found in five out of 117 females (4%) and in none of 19 males (0%), and BRCA2 mutations were found in four out of 117 females (3%) and in two out of 19 males (10%). The proportions of BRCA1 and BRCA2 mutations coincided in site-specific female breast cancers (four out of 102; ie 4% each). BRCA1 and BRCA2 equally contributed to female breast cancers, with no familial clustering in those diagnosed before age 40 years (one out of 28; 4% each), and to female breast cancers, all ages, with familial clustering in one to two relatives (three out of 55; ie 5% each). In the latter subset of cases, BRCA1 mostly accounted for tumours diagnosed before age 40 years (two out of eight; 25%), and BRCA2 for tumours diagnosed after age 50 years (three out of 34; 9%). Regardless of family history, the respective contributions of BRCA1 and BRCA2 to site-specific female breast cancers diagnosed before age 40 years were 8% (three out of 36) and 3% (one out of 36). One BRCA1 mutation was detected among the 15 female probands from breast-ovarian/ovarian cancer families (7%). Among male breast cancers, BRCA2 mutations were identified in one out of five (20%) cases with family history and in one out of 14 (7%) apparently sporadic cases. No BRCA1 or BRCA2 mutations were found in female probands with nonfamilial bilateral breast cancer (10 cases) or in those with breast cancer associated with gastrointestinal, pancreatic or uterine cancers, synchronous/metachronous or in first-degree relative(s) (nine cases). These cases were all diagnosed after age 40 years.
Discussion:
Our results indicate a lack of relevant founder effects for BRCA1- and BRCA2-related disease in the sample of patients studied, which is consistent with other Italian studies and with ethnical and historical data. Overall, the contribution of BRCA1 and BRCA2 to breast/ovarian cancer in Italian patients appears to be less significant than in patients from communities with founder mutations. The present study is in agreement with direct estimates on other outbred populations, indicating that 7-10% of all female breast cancers that occur in patients aged under 40 years are due to BRCA1/BRCA2.
We found that BRCA1 and BRCA2 equally contributed to site-specific breast cancers who had one/two breast cancer-affected first-/second-degree relative(s) or who were diagnosed within age 40 years in the absence of family history. This is consistent with recent data that indicated that the respective frequencies of BRCA1 and BRCA2 mutations are comparable in early onset breast cancer. Considering the total population of patients analyzed here, however, BRCA1 and BRCA2 mutations were mostly found in cases with disease diagnosis before and after age 50 years, respectively. Moreover, in cases with familial clustering of site-specific breast cancer, BRCA1 mostly accounted for tumours diagnosed before age 40 years, and BRCA2 for tumours diagnosed after age 50 years. This is in agreement with a trend, which has been observed in other populations, for the proportion of cases with BRCA2 mutations to increase, and the proportion with mutations in BRCA1 to decrease, as the age at cancer onset increases.
As in other studies, the frequency of BRCA1/BRCA2 mutations taken together was lower than the estimated frequencies at comparable ages for all susceptibility alleles derived from the Contraceptive and Steroid Hormones (CASH) study. The discrepancy between direct data deriving from BRCA1/BRCA2 mutational analysis and CASH estimates could be due to several factors, including contribution of gene(s) other than BRCA1/BRCA2, differences between populations and relative insensitivity of mutational screening. Only BRCA1 mutations were found in breast/ovarian and site-specific ovarian cancer families. BRCA2, but not BRCA1 mutations were found in the male breast cancers. The overall proportion of males with BRCA2 mutations was high when compared with data from other studies on outbred populations, but was low compared with data from populations with founder effects.
The present results should be regarded as an approximation, because the following types of mutation are predicted to escape detection by the screening strategy used: mutations in noncoding regions; missense mutations within BRCA1 exon 11 and BRCA2 exons 10 and 11; large gene deletions; and mutations within the first and last 180 nucleotides of the amplicons analyzed by PTT.
PMCID: PMC13918  PMID: 11056688
BRCA1; BRCA2; breast; carcinoma; germline mutations; Italy
12.  Smoking and high-risk mammographic parenchymal patterns: a case-control study 
Breast Cancer Research  1999;2(1):59-63.
Current smoking was strongly and inversely associated with high-risk patterns, after adjustment for concomitant risk factors. Relative to never smokers, current smokers were significantly less likely to have a high-risk pattern. Similar results were obtained when the analysis was confined to postmenopausal women. Past smoking was not related to the mammographic parenchymal patterns. The overall effect in postmenopausal women lost its significance when adjusted for other risk factors for P2/DY patterns that were found to be significant in the present study, although the results are still strongly suggestive. The present data indicate that adjustment for current smoking status is important when evaluating the relationship between mammographic parenchymal pattern and breast cancer risk. They also indicate that smoking is a prominent potential confounder when analyzing effects of other risk factors such as obesity-related variables. It appears that parenchymal patterns may act as an informative biomarker of the effect of cigarette smoking on breast cancer risk.
Introduction:
Overall, epidemiological studies [1,2,3,4] have reported no substantial association between cigarette smoking and the risk of breast cancer. Some studies [5,6,7] reported a significant increase of breast cancer risk among smokers. In recent studies that addressed the association between breast cancer and cigarette smoking, however, there was some suggestion of a decreased risk [8,9,10], especially among current smokers, ranging from approximately 10 to 30% [9,10]. Brunet et al [11] reported that smoking might reduce the risk of breast cancer by 44% in carriers of BRCA1 or BRCA2 gene mutations. Wolfe [12] described four different mammographic patterns created by variations in the relative amounts of fat, epithelial and connective tissue in the breast, designated N1, P1, P2 and DY. Women with either P2 or DY pattern are considered at greater risk for breast cancer than those with N1 or P1 pattern [12,13,14,15]. There are no published studies that assessed the relationship between smoking and mammographic parenchymal patterns.
Aims:
To evaluate whether mammographic parenchymal patterns as classified by Wolfe, which have been positively associated with breast cancer risk, are affected by smoking. In this case-control study, nested within the European Prospective Investigation on Cancer in Norfolk (EPIC-Norfolk) cohort [16], the association between smoking habits and mammographic parenchymal patterns are examined. The full results will be published elsewhere.
Methods:
Study subjects were members of the EPIC cohort in Norwich who also attended the prevalence screening round at the Norwich Breast Screening Centre between November 1989 and December 1997, and were free of breast cancer at that screening. Cases were defined as women with a P2/DY Wolfe's mammographic parenchymal pattern on the prevalence screen mammograms. A total of 203 women with P2/DY patterns were identified as cases and were individually matched by date of birth (within 1 year) and date of prevalence screening (within 3 months) with 203 women with N1/P1 patterns who served as control individuals.
Two views, the mediolateral and craniocaudal mammograms, of both breasts were independently reviewed by two of the authors (ES and RW) to determine the Wolfe mammographic parenchymal pattern.
Considerable information on health and lifestyle factors was available from the EPIC Health and Lifestyle Questionnaire [16]. In the present study we examined the subjects' personal history of benign breast diseases, menstrual and reproductive factors, oral contraception and hormone replacement therapy, smoking, and anthropometric information such as body mass index and waist:hip ratio.
Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated by conditional logistic regression [17], and were adjusted for possible confounding factors.
Results:
The characteristics of the cases and controls are presented in Table 1. Cases were leaner than controls. A larger percentage of cases were nulliparous, premenopausal, current hormone replacement therapy users, had a personal history of benign breast diseases, and had had a hysterectomy. A larger proportion of controls had more than three births and were current smokers.
Table 2 shows the unadjusted and adjusted OR estimates for Wolfe's high-risk mammographic parenchymal patterns and smoking in the total study population and in postmenopausal women separately. Current smoking was strongly and inversely associated with high-risk patterns, after adjustment for concomitant risk factors. Relative to never smokers, current smokers were significantly less likely to have a high-risk pattern (OR 0.37, 95% CI 0.14-0.94). Similar results were obtained when the analysis was confined to postmenopausal women. Past smoking was not related to mammographic parenchymal patterns. The overall effect in postmenopausal women lost its significance when adjusted for other risk factors for P2/DY patterns that were found to be significant in the present study, although the results were still strongly suggestive. There was no interaction between cigarette smoking and body mass index.
Discussion:
In the present study we found a strong inverse relationship between current smoking and high-risk mammographic parenchymal patterns of breast tissue as classified by Wolfe [12]. These findings are not completely unprecedented; Greendale et al [18] found a reduced risk of breast density in association with smoking, although the magnitude of the reduction was unclear. The present findings suggest that this reduction is large.
Recent studies [9,10] have suggested that breast cancer risk may be reduced among current smokers. In a multicentre Italian case-control study, Braga et al [10] found that, relative to nonsmokers, current smokers had a reduced risk of breast cancer (OR 0.84, 95% CI 0.7-1.0). These findings were recently supported by Gammon et al [9], who reported that breast cancer risk in younger women (younger than 45 years) may be reduced among current smokers who began smoking at an early age (OR 0.59, 95% CI 0.41-0.85 for age 15 years or younger) and among long-term smokers (OR 0.70, 95% CI 0.52-0.94 for those who had smoked for 21 years or more).
The possible protective effect of smoking might be due to its anti-oestrogenic effect [1,2,19]. Recently there has been renewed interest in the potential effect of smoking on breast cancer risk, and whether individuals may respond differently on the basis of differences in metabolism of bioproducts of smoking [20,21]. Different relationships between smoking and breast cancer risk have been suggested that are dependent on the rapid or slow status of acetylators of aromatic amines [20,21]. More recent studies [22,23], however, do not support these findings.
The present study design minimized the opportunity for bias to influence the findings. Because subjects were unaware of their own case-control status, the possibility of recall bias in reporting smoking status was minimized. Systematic error in the assessment of mammograms was avoided because reading was done without knowledge of the risk factor data. Furthermore, the associations observed are unlikely to be explained by the confounding effect of other known breast cancer risk factors, because we adjusted for these in the analysis. We did not have information on passive smoking status, however, which has recently been reported to be a possible confounder [5,6,21,24].
The present data indicate that adjustment for current smoking status is important when evaluating the relationship between mammographic parenchymal pattern and breast cancer risk. They also indicate smoking as a prominent potential confounder when analyzing effects of other risk factors such as obesity-related variables. It seems that parenchymal patterns may act as an informative biomarker of the effect of cigarette smoking on breast cancer risk.
PMCID: PMC13911  PMID: 11056684
mammography; screening; smoking; Wolfe's parenchymal patterns
13.  Screening for Breast Cancer 
Context
Breast cancer screening in community practices may be different from that in randomized controlled trials. New screening modalities are becoming available.
Objectives
To review breast cancer screening, especially in the community and to examine evidence about new screening modalities.
Data Sources and Study Selection
English-language articles of randomized controlled trials assessing effectiveness of breast cancer screening were reviewed, as well as meta-analyses, systematic reviews, studies of breast cancer screening in the community, and guidelines. Also, studies of newer screening modalities were assessed.
Data Synthesis
All major US medical organizations recommend screening mammography for women aged 40 years and older. Screening mammography reduces breast cancer mortality by about 20% to 35% in women aged 50 to 69 years and slightly less in women aged 40 to 49 years at 14 years of follow-up. Approximately 95% of women with abnormalities on screening mammograms do not have breast cancer with variability based on such factors as age of the woman and assessment category assigned by the radiologist. Studies comparing full-field digital mammography to screen film have not shown statistically significant differences in cancer detection while the impact on recall rates (percentage of screening mammograms considered to have positive results) was unclear. One study suggested that computer-aided detection increases cancer detection rates and recall rates while a second larger study did not find any significant differences. Screening clinical breast examination detects some cancers missed by mammography, but the sensitivity reported in the community is lower (28% to 36%) than in randomized trials (about 54%). Breast self-examination has not been shown to be effective in reducing breast cancer mortality, but it does increase the number of breast biopsies performed because of false-positives. Magnetic resonance imaging and ultrasound are being studied for screening women at high risk for breast cancer but are not recommended for screening the general population. Sensitivity of magnetic resonance imaging in high-risk women has been found to be much higher than that of mammography but specificity is generally lower. Effect of the magnetic resonance imaging on breast cancer mortality is not known. A balanced discussion of possible benefits and harms of screening should be undertaken with each woman.
Conclusions
In the community, mammography remains the main screening tool while the effectiveness of clinical breast examination and self-examination are less. New screening modalities are unlikely to replace mammography in the near future for screening the general population.
doi:10.1001/jama.293.10.1245
PMCID: PMC3149836  PMID: 15755947
14.  Using a state cancer registry to recruit young breast cancer survivors and high-risk relatives: protocol of a randomized trial testing the efficacy of a targeted versus a tailored intervention to increase breast cancer screening 
BMC Cancer  2013;13:97.
Background
The Michigan Prevention Research Center, the University of Michigan Schools of Nursing, Public Health, and Medicine, and the Michigan Department of Community Health propose a multidisciplinary academic-clinical practice three-year project to increase breast cancer screening among young breast cancer survivors and their cancer-free female relatives at greatest risk for breast cancer.
Methods/design
The study has three specific aims: 1) Identify and survey 3,000 young breast cancer survivors (diagnosed at 20–45 years old) regarding their breast cancer screening utilization. 2) Identify and survey survivors’ high-risk relatives regarding their breast cancer screening utilization. 3) Test two versions (Targeted vs. Enhanced Tailored) of an intervention to increase breast cancer screening among survivors and relatives. Following approval by human subjects review boards, 3,000 young breast cancer survivors will be identified through the Michigan Cancer Registry and mailed an invitation letter and a baseline survey. The baseline survey will obtain information on the survivors’: a) current breast cancer screening status and use of genetic counseling; b) perceived barriers and facilitators to screening; c) family health history. Based on the family history information provided by survivors, we will identify up to two high-risk relatives per survivor. Young breast cancer survivors will be mailed consent forms and baseline surveys to distribute to their selected high-risk relatives. Relatives’ baseline survey will obtain information on their: a) current breast cancer screening status and use of genetic counseling; and b) perceived barriers and facilitators to screening. Young breast cancer survivors and high-risk relatives will be randomized as a family unit to receive two versions of an intervention aiming to increase breast cancer screening and use of cancer genetic services. A follow-up survey will be mailed 9 months after the intervention to survivors and high-risk relatives to evaluate the efficacy of each intervention version on: a) use of breast cancer screening and genetic counseling; b) perceived barriers and facilitators to screening; c) self-efficacy in utilizing cancer genetic and screening services; d) family support related to screening; e) knowledge of breast cancer genetics; and f) satisfaction with the intervention.
Discussion
The study will enhance efforts of the state of Michigan surrounding cancer prevention, control, and public health genomics.
Trial registration
NCT01612338
doi:10.1186/1471-2407-13-97
PMCID: PMC3599993  PMID: 23448100
Breast cancer screening; Familial breast cancer; Young breast cancer survivors; High-risk relatives; Randomized trial; Targeted and enhanced tailored intervention; Screening mammography; Genetic testing; Cancer registry; State-wide community-based sample
15.  Effectiveness of Computer-Aided Detection in Community Mammography Practice 
Background
Computer-aided detection (CAD) is applied during screening mammography for millions of US women annually, although it is uncertain whether CAD improves breast cancer detection when used by community radiologists.
Methods
We investigated the association between CAD use during film-screen screening mammography and specificity, sensitivity, positive predictive value, cancer detection rates, and prognostic characteristics of breast cancers (stage, size, and node involvement). Records from 684 956 women who received more than 1.6 million film-screen mammograms at Breast Cancer Surveillance Consortium facilities in seven states in the United States from 1998 to 2006 were analyzed. We used random-effects logistic regression to estimate associations between CAD and specificity (true-negative examinations among women without breast cancer), sensitivity (true-positive examinations among women with breast cancer diagnosed within 1 year of mammography), and positive predictive value (breast cancer diagnosed after positive mammograms) while adjusting for mammography registry, patient age, time since previous mammography, breast density, use of hormone replacement therapy, and year of examination (1998–2002 vs 2003–2006). All statistical tests were two-sided.
Results
Of 90 total facilities, 25 (27.8%) adopted CAD and used it for an average of 27.5 study months. In adjusted analyses, CAD use was associated with statistically significantly lower specificity (OR = 0.87, 95% confidence interval [CI] = 0.85 to 0.89, P < .001) and positive predictive value (OR = 0.89, 95% CI = 0.80 to 0.99, P = .03). A non-statistically significant increase in overall sensitivity with CAD (OR = 1.06, 95% CI = 0.84 to 1.33, P = .62) was attributed to increased sensitivity for ductal carcinoma in situ (OR = 1.55, 95% CI = 0.83 to 2.91; P = .17), although sensitivity for invasive cancer was similar with or without CAD (OR = 0.96, 95% CI = 0.75 to 1.24; P = .77). CAD was not associated with higher breast cancer detection rates or more favorable stage, size, or lymph node status of invasive breast cancer.
Conclusion
CAD use during film-screen screening mammography in the United States is associated with decreased specificity but not with improvement in the detection rate or prognostic characteristics of invasive breast cancer.
doi:10.1093/jnci/djr206
PMCID: PMC3149041  PMID: 21795668
16.  Tumor phenotype and breast density in distinct categories of interval cancer: results of population-based mammography screening in Spain 
Introduction
Interval cancers are tumors arising after a negative screening episode and before the next screening invitation. They can be classified into true interval cancers, false-negatives, minimal-sign cancers, and occult tumors based on mammographic findings in screening and diagnostic mammograms. This study aimed to describe tumor-related characteristics and the association of breast density and tumor phenotype within four interval cancer categories.
Methods
We included 2,245 invasive tumors (1,297 screening-detected and 948 interval cancers) diagnosed from 2000 to 2009 among 645,764 women aged 45 to 69 who underwent biennial screening in Spain. Interval cancers were classified by a semi-informed retrospective review into true interval cancers (n = 455), false-negatives (n = 224), minimal-sign (n = 166), and occult tumors (n = 103). Breast density was evaluated using Boyd’s scale and was conflated into: <25%; 25 to 50%; 50 to 75%; >75%. Tumor-related information was obtained from cancer registries and clinical records. Tumor phenotype was defined as follows: luminal A: ER+/HER2- or PR+/HER2-; luminal B: ER+/HER2+ or PR+/HER2+; HER2: ER-/PR-/HER2+; triple-negative: ER-/PR-/HER2-. The association of tumor phenotype and breast density was assessed using a multinomial logistic regression model. Adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. All statistical tests were two-sided.
Results
Forty-eight percent of interval cancers were true interval cancers and 23.6% false-negatives. True interval cancers were associated with HER2 and triple-negative phenotypes (OR = 1.91 (95% CI:1.22-2.96), OR = 2.07 (95% CI:1.42-3.01), respectively) and extremely dense breasts (>75%) (OR = 1.67 (95% CI:1.08-2.56)). However, among true interval cancers a higher proportion of triple-negative tumors was observed in predominantly fatty breasts (<25%) than in denser breasts (28.7%, 21.4%, 11.3% and 14.3%, respectively; <0.001). False-negatives and occult tumors had similar phenotypic characteristics to screening-detected cancers, extreme breast density being strongly associated with occult tumors (OR = 6.23 (95% CI:2.65-14.66)). Minimal-sign cancers were biologically close to true interval cancers but showed no association with breast density.
Conclusions
Our findings revealed that both the distribution of tumor phenotype and breast density play specific and independent roles in each category of interval cancer. Further research is needed to understand the biological basis of the overrepresentation of triple-negative phenotype among predominantly fatty breasts in true interval cancers.
doi:10.1186/bcr3595
PMCID: PMC3979164  PMID: 24410848
17.  Birth Outcome in Women with Previously Treated Breast Cancer—A Population-Based Cohort Study from Sweden 
PLoS Medicine  2006;3(9):e336.
Background
Data on birth outcome and offspring health after the appearance of breast cancer are limited. The aim of this study was to assess the risk of adverse birth outcomes in women previously treated for invasive breast cancer compared with the general population of mothers.
Methods and Findings
Of all 2,870,932 singleton births registered in the Swedish Medical Birth Registry during 1973–2002, 331 first births following breast cancer surgery—with a mean time to pregnancy of 37 mo (range 7–163)—were identified using linkage with the Swedish Cancer Registry.
Logistic regression analysis was used. The estimates were adjusted for maternal age, parity, and year of delivery. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate infant health and mortality, delivery complications, the risk of preterm birth, and the rates of instrumental delivery and cesarean section.
The large majority of births from women previously treated for breast cancer had no adverse events. However, births by women exposed to breast cancer were associated with an increased risk of delivery complications (OR 1.5, 95% CI 1.2–1.9), cesarean section (OR 1.3, 95% CI 1.0–1.7), very preterm birth (<32 wk) (OR 3.2, 95% CI 1.7–6.0), and low birth weight (<1500 g) (OR 2.9, 95% CI 1.4–5.8). A tendency towards an increased risk of malformations among the infants was seen especially in the later time period (1988–2002) (OR 2.1, 95% CI 1.2–3.7).
Conclusions
It is reassuring that births overall were without adverse events, but our findings indicate that pregnancies in previously treated breast cancer patients should possibly be regarded as higher risk pregnancies, with consequences for their surveillance and management.
The large majority of births from women previously treated for breast cancer had no adverse events, but such pregnancies might benefit from increased surveillance and management.
Editors' Summary
Background.
More women of all ages are developing breast cancer than ever before. In the US, one woman in eight will now develop this disease during her lifetime. For most of these women, their breast cancer diagnosis will come late in life, but a fifth of breast cancers are diagnosed before the age of 50. These days, the long-term outlook for women with breast cancer is quite good; 80% of women who receive a diagnosis of breast cancer survive more than five years. These figures, together with a trend towards starting families later in life—since the late 1970s birth rates for women in their late 30s and 40s have more than doubled in the US, and in Sweden the average age for having a first baby is now 29 years—mean that many women who have had breast cancer want to have children. One estimate is that up to 7% of women who are fertile after treatment for breast cancer will later have children.
Why Was This Study Done?
Pregnancy seems to have no adverse affects on women who have had breast cancer—there is no evidence that pregnancy can trigger a relapse. However, little is known about whether the chemotherapy and radiotherapy used to treat breast cancer have any long-lasting effects that might result in a poor birth outcome such as stillbirth, low birth weight, premature delivery, or abnormalities in the baby (congenital abnormalities). In this study, the researchers assessed the risk of adverse birth outcomes in women previously treated for breast cancer in Sweden.
What Did the Researchers Do and Find?
Nearly three million singleton births that occurred between 1973 and 2002 are recorded in the Swedish Medical Birth Registry. The researchers linked this information with that in the Swedish Cancer Registry to identify 331 first births after treatment for invasive breast cancer (cancer that has spread from where it started to grow in the breast). The birth registry includes details on maternal age and health, child's birth weight, whether the delivery was preterm, and whether the child had any congenital abnormalities, so the researchers were able to compare birth outcomes in these 331 births with those in the general population. They discovered that most births after breast cancer treatment went smoothly. There was no increase in stillbirths, but there were slightly more delivery complications in the women who had had breast cancer than in the general population, and a slight increase in babies born prematurely or with low birth weight. Finally, a few more babies with congenital abnormalities were born to women after breast cancer treatment than to women in the general population.
What Do These Findings Mean?
Overall, these results should reassure women who are thinking about having children after breast cancer about the health of their future offspring. However, they do suggest that these women may need careful monitoring during late pregnancy and delivery. This result was not predicted by the researchers who performed the study. Before starting the study, they thought that there would be no difference in birth outcomes between patients previously treated for breast cancer and the general population. Furthermore, a recently published similar study in Denmark found no increased risk of preterm birth, low birth weight, or congenital abnormalities after breast cancer. Differences between the two countries in the accuracy of their registries or in the use of chemotherapy and radiotherapy treatments may account for this difference in results. Additional studies are now needed in other populations to resolve this discrepancy and to provide more information about how breast cancer treatment might affect birth outcomes. For example, the current study did not provide any information about whether specific chemotherapy regimens or different types of breast cancer might put women at a higher risk of adverse birth outcomes, or whether the time between the cancer diagnosis and treatment and the pregnancy made a difference.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030336.
MedlinePlus encyclopedia entry on breast cancer
National Cancer Institute information for patients and physicians on breast cancer, including links to pages on breast cancer and pregnancy
Cancer Research UK's information on breast cancer for patients, and statistics on breast cancer in the UK
• Wikipedia page on breast cancer (note: Wikipedia is a free online encyclopedia that anyone can edit)
Royal College of Obstetricians and Gynaecologists guidelines for physicians on pregnancy and breast cancer
doi:10.1371/journal.pmed.0030336
PMCID: PMC1564170  PMID: 16968117
18.  DEAR1 Is a Dominant Regulator of Acinar Morphogenesis and an Independent Predictor of Local Recurrence-Free Survival in Early-Onset Breast Cancer 
PLoS Medicine  2009;6(5):e1000068.
Ann Killary and colleagues describe a new gene that is genetically altered in breast tumors, and that may provide a new breast cancer prognostic marker.
Background
Breast cancer in young women tends to have a natural history of aggressive disease for which rates of recurrence are higher than in breast cancers detected later in life. Little is known about the genetic pathways that underlie early-onset breast cancer. Here we report the discovery of DEAR1 (ductal epithelium–associated RING Chromosome 1), a novel gene encoding a member of the TRIM (tripartite motif) subfamily of RING finger proteins, and provide evidence for its role as a dominant regulator of acinar morphogenesis in the mammary gland and as an independent predictor of local recurrence-free survival in early-onset breast cancer.
Methods and Findings
Suppression subtractive hybridization identified DEAR1 as a novel gene mapping to a region of high-frequency loss of heterozygosity (LOH) in a number of histologically diverse human cancers within Chromosome 1p35.1. In the breast epithelium, DEAR1 expression is limited to the ductal and glandular epithelium and is down-regulated in transition to ductal carcinoma in situ (DCIS), an early histologic stage in breast tumorigenesis. DEAR1 missense mutations and homozygous deletion (HD) were discovered in breast cancer cell lines and tumor samples. Introduction of the DEAR1 wild type and not the missense mutant alleles to complement a mutation in a breast cancer cell line, derived from a 36-year-old female with invasive breast cancer, initiated acinar morphogenesis in three-dimensional (3D) basement membrane culture and restored tissue architecture reminiscent of normal acinar structures in the mammary gland in vivo. Stable knockdown of DEAR1 in immortalized human mammary epithelial cells (HMECs) recapitulated the growth in 3D culture of breast cancer cell lines containing mutated DEAR1, in that shDEAR1 clones demonstrated disruption of tissue architecture, loss of apical basal polarity, diffuse apoptosis, and failure of lumen formation. Furthermore, immunohistochemical staining of a tissue microarray from a cohort of 123 young female breast cancer patients with a 20-year follow-up indicated that in early-onset breast cancer, DEAR1 expression serves as an independent predictor of local recurrence-free survival and correlates significantly with strong family history of breast cancer and the triple-negative phenotype (ER−, PR−, HER-2−) of breast cancers with poor prognosis.
Conclusions
Our data provide compelling evidence for the genetic alteration and loss of expression of DEAR1 in breast cancer, for the functional role of DEAR1 in the dominant regulation of acinar morphogenesis in 3D culture, and for the potential utility of an immunohistochemical assay for DEAR1 expression as an independent prognostic marker for stratification of early-onset disease.
Editors' Summary
Background
Each year, more than one million women discover that they have breast cancer. This type of cancer begins when cells in the breast that line the milk-producing glands or the tubes that take the milk to the nipples (glandular and ductal epithelial cells, respectively) acquire genetic changes that allow them to grow uncontrollably and to move around the body (metastasize). The uncontrolled division leads to the formation of a lump that can be detected by mammography (a breast X-ray) or by manual breast examination. Breast cancer is treated by surgical removal of the lump or, if the cancer has started to spread, by removal of the whole breast (mastectomy). Surgery is usually followed by radiotherapy or chemotherapy. These “adjuvant” therapies are designed to kill any remaining cancer cells but can make patients very ill. Generally speaking, the outlook for women with breast cancer is good. In the US, for example, nearly 90% of affected women are still alive five years after their diagnosis.
Why Was This Study Done?
Although breast cancer is usually diagnosed in women in their 50s or 60s, some women develop breast cancer much earlier. In these women, the disease is often very aggressive. Compared to older women, young women with breast cancer have a lower overall survival rate and their cancer is more likely to recur locally or to metastasize. It would be useful to be able to recognize those younger women at the greatest risk of cancer recurrence so that they could be offered intensive surveillance and adjuvant therapy; those women at a lower risk could have gentler treatments. To achieve this type of “stratification,” the genetic changes that underlie breast cancer in young women need to be identified. In this study, the researchers discover a gene that is genetically altered (by mutations or deletion) in early-onset breast cancer and then investigate whether its expression can predict outcomes in women with this disease.
What Did the Researchers Do and Find?
The researchers used “suppression subtractive hybridization” to identify a new gene in a region of human Chromosome 1 where loss of heterozygosity (LOH; a genetic alteration associated with cancer development) frequently occurs. They called the gene DEAR1 (ductal epithelium-associated RING Chromosome 1) to indicate that it is expressed in ductal and glandular epithelial cells and encodes a “RING finger” protein (specifically, a subtype called a TRIM protein; RING finger proteins such as BRCA1 and BRCA2 have been implicated in early cancer development and in a large fraction of inherited breast cancers). DEAR1 expression was reduced or lost in several ductal carcinomas in situ (a local abnormality that can develop into breast cancer) and advanced breast cancers, the researchers report. Furthermore, many breast tumors carried DEAR1 missense mutations (genetic changes that interfere with the normal function of the DEAR1 protein) or had lost both copies of DEAR1 (the human genome contains two copies of most genes). To determine the function of DEAR1, the researchers replaced a normal copy of DEAR1 into a breast cancer cell that had a mutation in DEAR1. They then examined the growth of these genetically manipulated cells in special three-dimensional cultures. The breast cancer cells without DEAR1 grew rapidly without an organized structure while the breast cancer cells containing the introduced copy of DEAR1 formed structures that resembled normal breast acini (sac-like structures that secrete milk). In normal human mammary epithelial cells, the researchers silenced DEAR1 expression and also showed that without DEAR1, the normal mammary cells lost their ability to form proper acini. Finally, the researchers report that DEAR1 expression (detected “immunohistochemically”) was frequently lost in women who had had early-onset breast cancer and that the loss of DEAR1 expression correlated with reduced local recurrence-free survival, a strong family history of breast cancer and with a breast cancer subtype that has a poor outcome.
What Do These Findings Mean?
These findings indicate that genetic alteration and loss of expression of DEAR1 are common in breast cancer. Although laboratory experiments may not necessarily reflect what happens in people, the results from the three-dimensional culture of breast epithelial cells suggest that DEAR1 may regulate the normal acinar structure of the breast. Consequently, loss of DEAR1 expression could be an early event in breast cancer development. Most importantly, the correlation between DEAR1 expression and both local recurrence in early-onset breast cancer and a breast cancer subtype with a poor outcome suggests that it might be possible to use DEAR1 expression to identify women with early-onset breast cancer who have an increased risk of local recurrence so that they get the most appropriate treatment for their cancer.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000068.
This study is further discussed in a PLoS Medicine Perspective by Senthil Muthuswamy
The US National Cancer Institute provides detailed information for patients and health professionals on all aspects of breast cancer, including information on genetic alterations in breast cancer (in English and Spanish)
The MedlinePlus Encyclopedia provides information for patients about breast cancer; MedlinePlus also provides links to many other breast cancer resources (in English and Spanish)
The UK charities Cancerbackup (now merged with MacMillan Cancer Support) and Cancer Research UK also provide detailed information about breast cancer
doi:10.1371/journal.pmed.1000068
PMCID: PMC2673042  PMID: 19536326
19.  Engaging diverse underserved communities to bridge the mammography divide 
BMC Public Health  2011;11:47.
Background
Breast cancer screening continues to be underutilized by the population in general, but is particularly underutilized by traditionally underserved minority populations. Two of the most at risk female minority groups are American Indians/Alaska Natives (AI/AN) and Latinas. American Indian women have the poorest recorded 5-year cancer survival rates of any ethnic group while breast cancer is the number one cause of cancer mortality among Latina women. Breast cancer screening rates for both minority groups are near or at the lowest among all racial/ethnic groups. As with other health screening behaviors, women may intend to get a mammogram but their intentions may not result in initiation or follow through of the examination process. An accumulating body of research, however, demonstrates the efficacy of developing 'implementation intentions' that define when, where, and how a specific behavior will be performed. The formulation of intended steps in addition to addressing potential barriers to test completion can increase a person's self-efficacy, operationalize and strengthen their intention to act, and close gaps between behavioral intention and completion. To date, an evaluation of the formulation of implementation intentions for breast cancer screening has not been conducted with minority populations.
Methods/Design
In the proposed program, community health workers will meet with rural-dwelling Latina and American Indian women one-on-one to educate them about breast cancer and screening and guide them through a computerized and culturally tailored "implementation intentions" program, called Healthy Living Kansas - Breast Health, to promote breast cancer screening utilization. We will target Latina and AI/AN women from two distinct rural Kansas communities. Women attending community events will be invited by CHWs to participate and be randomized to either a mammography "implementation intentions" (MI2) intervention or a comparison general breast cancer prevention informational intervention (C). CHWs will be armed with notebook computers loaded with our Healthy Living Kansas - Breast Health program and guide their peers through the program. Women in the MI2 condition will receive assistance with operationalizing their screening intentions and identifying and addressing their stated screening barriers with the goal of guiding them toward accessing screening services near their community. Outcomes will be evaluated at 120-days post randomization via self-report and will include mammography utilization status, barriers, and movement along a behavioral stages of readiness to screen model.
Discussion
This highly innovative project will be guided and initiated by AI/AN and Latina community members and will test the practical application of emerging behavioral theory among minority persons living in rural communities.
Trial Registration
ClinicalTrials (NCT): NCT01267110
doi:10.1186/1471-2458-11-47
PMCID: PMC3036625  PMID: 21255424
20.  Polymorphic repeat in AIB1 does not alter breast cancer risk 
Breast Cancer Research : BCR  2000;2(5):378-385.
We assessed the association between a glutamine repeat polymorphism in AIB1 and breast cancer risk in a case-control study (464 cases, 624 controls) nested within the Nurses' Health Study cohort. We observed no association between AIB1 genotype and breast cancer incidence, or specific tumor characteristics. These findings suggest that AIB1 repeat genotype does not influence postmenopausal breast cancer risk among Caucasian women in the general population.
Introduction:
A causal association between endogenous and exogenous estrogens and breast cancer has been established. Steroid hormones regulate the expression of proteins that are involved in breast cell proliferation and development after binding to their respective steroid hormone receptors. Coactivator and corepressor proteins have recently been identified that interact with steroid hormone receptors and modulate transcriptional activation [1]. AIB1 (amplified in breast 1) is a member of the steroid receptor coactivator (SRC) family that interacts with estrogen receptor (ER)α in a ligand-dependent manner, and increases estrogen-dependent transcription [2]. Amplification and overexpression of AIB1 has been observed in breast and ovarian cancer cell lines and in breast tumors [2,3]. A polymorphic stretch of glutamine amino acids, with unknown biologic function, has recently been described in the carboxyl-terminal region of AIB1 [4]. Among women with germline BRCA1 mutations, significant positive associations were observed between AIB1 alleles with 26 or fewer glutamine repeats and breast cancer risk [5]
Aim:
To establish whether AIB1 repeat alleles are associated with breast cancer risk and specific tumor characteristics among Caucasian women.
Patients and methods:
We evaluated associations prospectively between AIB1 alleles and breast cancer risk in the Nurses' Health Study using a nested case-control design. The Nurses' Health Study was initiated in 1976, when 121 700 US-registered nurses between the ages of 30 and 55 years returned an initial questionnaire reporting medical histories and baseline health-related exposures. Between 1989 and 1990 blood samples were collected from 32 826 women. Eligible cases in this study consisted of women with pathologically confirmed incident breast cancer from the subcohort who gave a blood specimen. Cases with a diagnosis anytime after blood collection up to June 1, 1994, with no previously diagnosed cancer except for nonmelanoma skin cancer were included. Controls were randomly selected participants who gave a blood sample and were free of diagnosed cancer (except nonmelanoma skin cancer) up to and including the interval in which the cases were diagnosed, and were matched to cases on year of birth, menopausal status, postmenopausal hormone use, and time of day, month and fasting status at blood sampling. The nested case-control study consisted of 464 incident breast cancer cases and 624 matched controls. The protocol was approved by the Committee on Human Subjects, Brigham and Womens' Hospital, Boston, Massachusetts USA. Information regarding breast cancer risk factors was obtained from the 1976 baseline questionnaire, subsequent biennial questionnaires, and a questionnaire that was completed at the time of blood sampling. Histopathologic characteristics, such as stage, tumor size and ER and progesterone receptor (PR) status, were ascertained from medical records when available and used in case subgroup analyses.
AIB1 repeat alleles were determined by automated fluorescence-based fragment detection from polymerase chain reaction (PCR)-amplified DNA extracted from peripheral blood lymphocytes. Fluorescent 5' -labeled primers were utilized for PCR amplification, and glutamine repeat number discrimination was performed using the ABI Prism 377 DNA Sequencer (Perkin-Elmer, Foster City, CA, USA). Genotyping was performed by laboratory personnel who were blinded to case-control status, and blinded quality control samples were inserted to validate genotyping identification procedures (n = 110); concordance for the blinded samples was 100%. Methods regarding plasma hormone assays have previously been reported [6]. Conditional and unconditional logistic regression models, including terms for the matching variables and other potential confounders, were used to assess the association of AIB1 alleles and breast cancer characterized by histologic subtype, stage of disease, and ER and PR status. We also evaluated whether breast cancer risk associated with AIB1 genotype differed within strata of established breast cancer risk factors, and whether repeat length in AIB1 indirectly influenced plasma hormone levels.
Results:
The case-control comparisons of established breast cancer risk factors among these women have previously been reported [7], and are generally consistent with expectation. The mean age of the women was 58.3 (standard deviation [SD] 7.1) years, ranging from 43 to 69 years at blood sampling. There were 188 premenopausal and 810 postmenopausal women, with mean ages of 48.1 (SD 2.8) years and 61.4 (SD 5.0) years, respectively, at blood sampling. Women in this study were primarily white; Asians, African-Americans and Hispanics comprised less than 1% of cases or controls.
The distribution of AIB1 glutamine repeat alleles and AIB1 genotypes for cases and controls are presented in Table 1. Women with AIB1 alleles of 26 glutamine repeats or fewer were not at increased risk for breast cancer (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.75-1.36; Table 2). Results were also similar by menopausal status and in analyses additionally adjusting for established breast cancer risk factors. Among premenopausal women, the OR for women with at least one allele with 26 glutamine repeats or fewer was 0.82 (95% Cl 0.37-1.81), and among postmenopausal women the OR was 1.09 (95% Cl 0.78-1.52; Table 2). We did not observe evidence of a positive association between shorter repeat length and advanced breast cancer, defined as women with breast cancer having one or more involved nodes (OR 1.07, 95% Cl 0.64-1.78), or with cancers with a hormone-dependent phenotype (ER-positive: OR 1.16, 95% Cl 0.81-1.65; Table 3). No associations were observed among women who had one or more alleles with 26 glutamine repeats or fewer, with or without a family history of breast cancer (family history: OR 1.09; 95% Cl 0.46-2.58; no family history: OR 0.94; 95% Cl 0.68-1.31; test for interaction P = 0.65). We also did not observe associations with breast cancer risk to be modified by other established breast cancer risk factors. Among postmenopausal controls not using postmenopausal hormones, geometric least-squared mean plasma levels of estrone sulfate and estrone were similar among carriers and noncarriers of AIB1 alleles with 26 glutamine repeats or fewer (both differences: ≤ +3.5%; P >0.50). Mean levels of estradiol were slightly, but nonsignificantly elevated among carriers of alleles with 26 glutamine repeats or fewer (+11.6%; P = 0.08).
Discussion:
In this population-based nested case-control study, women with at most 26 repeating glutamine codons (CAG/CAA) within the carboxyl terminus of AIB1 were not at increased risk for breast cancer. We did not observe shorter repeat alleles to be positively associated with breast cancer grouped by histologic subtype, stage of disease, or by ER and PR status. These data suggest that AIB1 repeat length is not a strong independent risk factor for postmenopausal breast cancer, and does not modify the clinical presentation of the tumor among Caucasian women in the general population.
PMCID: PMC13920  PMID: 11056690
AIB1 polymorphism; breast cancer; genetic susceptibility; molecular epidemiology
21.  Distribution of Breast Density in Iranian Women and its Association with Breast Cancer Risk Factors 
Background:
Breast cancer is one of the most common cancers and the first-leading cause of cancer deaths among women in the world. Indeed, breast cancer is ranked as the first malignancy among Iranian women. Breast density, defined as the percentage of fibro glandular breast tissue in mammographic images, is one of the known risk factors for breast cancer. According to American college of radiology-Breast Imaging Reporting and Data System (ACR-BIRADS), mammographic density is divided into four categories. Studies have shown that increased breast density is associated with significant increase in breast cancer risk. Therefore, it is assumed that breast density should be associated with other breast cancer risk factors.
Objectives:
The aim of this study was to assess the epidemiologic distribution of breast density of the patients in a referral center in Iran, and to evaluate the association of high breast density and breast cancer risk factors and other factors that may possibly affect the mammographic density according to previous studies.
Patients and Methods:
In an analytical cross-sectional study, 728 of those who had referred to Imam Khomeini Imaging Center either for diagnostic or screening purposes, participated in the study, after filling out the informed consent form, the survey questionnaire based survey assessing breast cancer risk factors affecting the breast density and related demographic features, was conducted. SPSS 11.5 software and chi-square, t-test and logistic regression tests were used to analyze the data.
Results:
Most of patients (75%) in categories 2 and 3 of mammographic density had a breast density of 51.9%, however, this amount was less (49.2%) in screening mammograms, while in diagnosing group it was more (51.6%). The Findings showed an increase in age, body mass index (BMI), duration of breast feeding, and also to be menopause e, unemployed and married, younger than 29 years old at first delivery, having children up to 8 and smoking are associated with less breast density. Diagnostic mammograms and symptomatic patients showed denser breasts. But density had no association with oral contraceptives pill (OCP) consumption or hormone replacement therapy or calcium and/or vitamin D consumption, age at menarche and menopause, menstruation cycle phase and family history of breast cancer. Age at the first delivery, menopausal status and parity were independently associated with breast density.
Conclusions:
Density distribution and risk factors prevalence is different among symptomatic patients and the diagnostic mammograms of the screened persons, hence such information should be considered in the patient managements. In order to consider the effect of marriage and parity on decreasing the breast density, basic consultations should be performed. Smokers and obese women may falsely show low breast density while they may be in high-risk group. In this study no specific phase of menstrual cycle is suggested for mammographic examinations.
doi:10.5812/ircmj.16615
PMCID: PMC3955513  PMID: 24693398
Breast Neoplasms; Mammography; Mass Screening
22.  Short-Term Outcomes of Screening Mammography Using Computer-Aided Detection 
Annals of internal medicine  2013;158(8):580-587.
Background
Computer-aided detection (CAD) has rapidly diffused into screening mammography practice despite limited and conflicting data on its clinical effect.
Objective
To determine associations between CAD use during screening mammography and the incidence of ductal carcinoma in situ (DCIS) and invasive breast cancer, invasive cancer stage, and diagnostic testing.
Design
Retrospective cohort study.
Setting
Medicare program.
Participants
Women aged 67 to 89 years having screening mammography between 2001 and 2006 in U.S. SEER (Surveillance, Epidemiology and End Results) regions (409 459 mammograms from 163 099 women).
Measurements
Incident DCIS and invasive breast cancer within 1 year after mammography, invasive cancer stage, and diagnostic testing within 90 days after screening among women without breast cancer.
Results
From 2001 to 2006, CAD prevalence increased from 3.6% to 60.5%. Use of CAD was associated with greater DCIS incidence (adjusted odds ratio [OR], 1.17 [95% CI, 1.11 to 1.23]) but no difference in invasive breast cancer incidence (adjusted OR, 1.00 [CI, 0.97 to 1.03]). Among women with invasive cancer, CAD was associated with greater likelihood of stage I to II versus III to IV cancer (adjusted OR, 1.27 [CI, 1.14 to 1.41]). In women without breast cancer, CAD was associated with increased odds of diagnostic mammography (adjusted OR, 1.28 [CI, 1.27 to 1.29]), breast ultrasonography (adjusted OR, 1.07 [CI, 1.06 to 1.09]), and breast biopsy (adjusted OR, 1.10 [CI, 1.08 to 1.12]).
Limitation
Short follow-up for cancer stage, potential unmeasured confounding, and uncertain generalizability to younger women.
Conclusion
Use of CAD during screening mammography among Medicare enrollees is associated with increased DCIS incidence, the diagnosis of invasive breast cancer at earlier stages, and increased diagnostic testing among women without breast cancer.
Primary Funding Source
Center for Healthcare Policy and Research, University of California, Davis.
doi:10.7326/0003-4819-158-8-201304160-00002
PMCID: PMC3772716  PMID: 23588746
23.  Subtyping of Breast Cancer by Immunohistochemistry to Investigate a Relationship between Subtype and Short and Long Term Survival: A Collaborative Analysis of Data for 10,159 Cases from 12 Studies 
PLoS Medicine  2010;7(5):e1000279.
Paul Pharoah and colleagues evaluate the prognostic significance of immunohistochemical subtype classification in more than 10,000 breast cancer cases with early disease, and examine the influence of a patient's survival time on the prediction of future survival.
Background
Immunohistochemical markers are often used to classify breast cancer into subtypes that are biologically distinct and behave differently. The aim of this study was to estimate mortality for patients with the major subtypes of breast cancer as classified using five immunohistochemical markers, to investigate patterns of mortality over time, and to test for heterogeneity by subtype.
Methods and Findings
We pooled data from more than 10,000 cases of invasive breast cancer from 12 studies that had collected information on hormone receptor status, human epidermal growth factor receptor-2 (HER2) status, and at least one basal marker (cytokeratin [CK]5/6 or epidermal growth factor receptor [EGFR]) together with survival time data. Tumours were classified as luminal and nonluminal tumours according to hormone receptor expression. These two groups were further subdivided according to expression of HER2, and finally, the luminal and nonluminal HER2-negative tumours were categorised according to expression of basal markers. Changes in mortality rates over time differed by subtype. In women with luminal HER2-negative subtypes, mortality rates were constant over time, whereas mortality rates associated with the luminal HER2-positive and nonluminal subtypes tended to peak within 5 y of diagnosis and then decline over time. In the first 5 y after diagnosis the nonluminal tumours were associated with a poorer prognosis, but over longer follow-up times the prognosis was poorer in the luminal subtypes, with the worst prognosis at 15 y being in the luminal HER2-positive tumours. Basal marker expression distinguished the HER2-negative luminal and nonluminal tumours into different subtypes. These patterns were independent of any systemic adjuvant therapy.
Conclusions
The six subtypes of breast cancer defined by expression of five markers show distinct behaviours with important differences in short term and long term prognosis. Application of these markers in the clinical setting could have the potential to improve the targeting of adjuvant chemotherapy to those most likely to benefit. The different patterns of mortality over time also suggest important biological differences between the subtypes that may result in differences in response to specific therapies, and that stratification of breast cancers by clinically relevant subtypes in clinical trials is urgently required.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Each year, more than one million women discover they have breast cancer. Breast cancer begins when cells in the breast's milk-producing glands or in the tubes (ducts) that take milk to the nipples acquire genetic changes that allow them to divide uncontrollably and to move around the body (metastasize). The uncontrolled cell division leads to the formation of a lump that can be detected by mammography (a breast X-ray) or by manual breast examination. Breast cancer is treated by surgical removal of the lump or, if the cancer has started to spread, by removal of the whole breast (mastectomy). Surgery is usually followed by radiotherapy or chemotherapy. These “adjuvant” therapies are designed to kill any remaining cancer cells but can make women very ill. Generally speaking, the outlook (prognosis) for women with breast cancer is good. In the United States, for example, nearly 90% of affected women are still alive five years after their diagnosis.
Why Was This Study Done?
Because there are several types of cells in the milk ducts and glands, there are several subtypes of breast cancer. Luminal tumors, for example, begin in the cells that line the ducts and glands and usually grow slowly; basal-type tumors arise in deeper layers of the ducts and glands and tend to grow quickly. Clinicians need to distinguish between different breast cancer subtypes so that they can give women a realistic prognosis and can give adjuvant treatments to those women who are most likely to benefit. One way to distinguish between different subtypes is to stain breast cancer samples using antibodies (immune system proteins) that recognize particular proteins (antigens). This “immunohistochemical” approach can identify several breast cancer subtypes but its prognostic value and the best way to classify breast tumors remains unclear. In this study, the researchers investigate the survival over time of women with six major subtypes of breast cancer classified using five immunohistochemical markers: the estrogen receptor and the progesterone receptor (two hormone receptors expressed by luminal cells), the human epidermal growth factors receptor-2 (HER2, a protein marker used to select specific adjuvant therapies), and CK5/6 and EGFR (proteins expressed by basal cells).
What Did the Researchers Do and Find?
The researchers pooled data on survival time and on the expression of the five immunohistochemical markers from more than 10,000 cases of breast cancer from 12 studies. They then divided the tumors into six subtypes on the basis of their marker expression: luminal (hormone receptor-positive), HER2-positive tumors; luminal, HER2-negative, basal marker-positive tumors; luminal, HER2-negative, basal marker-negative tumors; nonluminal (hormone receptor-negative), HER2-positive tumors; nonluminal, HER2-negative, basal marker-positive tumors; and nonluminal, HER2-negative, basal marker-negative tumors. In the first five years after diagnosis, women with nonluminal tumor subtypes had the worst prognosis but at 15 years after diagnosis, women with luminal HER2-positive tumors had the worst prognosis. Furthermore, death rates (the percentage of affected women dying each year) differed by subtype over time. Thus, women with the two luminal HER2-negative subtypes were as likely to die soon after diagnosis as at later times whereas the death rates associated with nonluminal subtypes peaked within five years of diagnosis and then declined.
What Do These Findings Mean?
These and other findings indicate that the six subtypes of breast cancer defined by the expression of five immunohistochemical markers have distinct biological characteristics that are associated with important differences in short-term and long-term outcomes. Because different laboratories measured the immunohistochemical markers using different methods, it is possible that some of the tumors included in this study were misclassified. However, the finding of clear differences in the behavior of the immunochemically classified subtypes suggests that the use of the five markers for tumor classification might be robust enough for routine clinical practice. The application of these markers in the clinical setting, suggest the researchers, could improve the targeting of adjuvant therapies to those women most likely to benefit. Furthermore, note the researchers, these findings strongly suggest that subtype-specific responses should be evaluated in future clinical trials of treatments for breast cancer.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000279.
This study is further discussed in a PLoS Medicine Perspective by Stefan Ambs
The US National Cancer Institute provides detailed information for patients and health professionals on all aspects of breast cancer (in English and Spanish)
The American Cancer Society has a detailed guide to breast cancer, which includes information on the immunochemical classification of breast cancer subtypes
The UK charities MacMillan Cancer Support and Cancer Research UK also provide detailed information about breast cancer
The MedlinePlus Encyclopedia provides information for patients about breast cancer; Medline Plus provides links to many other breast cancer resources (in English and Spanish)
doi:10.1371/journal.pmed.1000279
PMCID: PMC2876119  PMID: 20520800
24.  A nurse-delivered intervention to reduce barriers to breast and cervical cancer screening in Chicago inner city clinics. 
Public Health Reports  1994;109(1):104-111.
An 18-month intervention was implemented to increase breast and cervical cancer screening among poor African-American women in Chicago. Breast and cervical cancer screening programs were set up in two public clinics, one community-based and the other hospital-based. Nurse clinicians and public health workers were used in these programs to recruit women in the clinics and in targeted community institutions to receive free breast and cervical cancer screening. The following barriers were specifically addressed by the intervention: accessibility of screening, knowledge about breast and cervical cancers, access to followup screening examinations, and access to treatment. A computerized followup system was specifically designed to track patients. During the 18 months of the intervention, 10,829 visits were made by 7,654 low-income women. A total of 84 cases of breast cancer and 9 cases of cervical cancer were detected. Awareness of the program, as measured by a survey after the completion of the intervention, increased in both clinics compared with baseline results. Knowledge about breast and cervical cancers also increased, as measured by scores on tests given before and after a class on breast and cervical cancers. Followup rates were 86 percent for women attending the programs. More than 90 percent of the women referred for evaluation of breast abnormalities kept an appointment. In summary, the intervention was successful in reducing barriers to breast and cervical cancer detection and in attracting a high-risk group of women.
PMCID: PMC1402249  PMID: 8303003
25.  Hip Fracture Incidence in Relation to Age, Menopausal Status, and Age at Menopause: Prospective Analysis 
PLoS Medicine  2009;6(11):e1000181.
Using data from the UK Million Women Study, Emily Banks and colleagues investigate the relationships between the incidence of hip fracture and a woman's age, menopausal status, and age at menopause.
Background
Bone mineral density is known to decrease rapidly after the menopause. There is limited evidence about the separate contributions of a woman's age, menopausal status and age at menopause to the incidence of hip fracture.
Methods and Findings
Over one million middle-aged women joined the UK Million Women Study in 1996–2001 providing information on their menopausal status, age at menopause, and other factors, which was updated, where possible, 3 y later. All women were registered with the UK National Health Service (NHS) and were routinely linked to information on cause-specific admissions to NHS hospitals. 561,609 women who had never used hormone replacement therapy and who provided complete information on menopausal variables (at baseline 25% were pre/perimenopausal and 75% postmenopausal) were followed up for a total of 3.4 million woman-years (an average 6.2 y per woman). During follow-up 1,676 (0.3%) were admitted to hospital with a first incident hip fracture. Among women aged 50–54 y the relative risk (RR) of hip fracture risk was significantly higher in postmenopausal than premenopausal women (adjusted RR 2.22, 95% confidence interval [CI] 1.22–4.04; p = 0.009); there were too few premenopausal women aged 55 y and over for valid comparisons. Among postmenopausal women, hip fracture incidence increased steeply with age (p<0.001), with rates being about seven times higher at age 70–74 y than at 50–54 y (incidence rates of 0.82 versus 0.11 per 100 women over 5 y). Among postmenopausal women of a given age there was no significant difference in hip fracture incidence between women whose menopause was due to bilateral oophorectomy compared to a natural menopause (adjusted RR 1.20, 95% CI 0.94–1.55; p = 0.15), and age at menopause had little, if any, effect on hip fracture incidence.
Conclusions
At around the time of the menopause, hip fracture incidence is about twice as high in postmenopausal than in premenopausal women, but this effect is short lived. Among postmenopausal women, age is by far the main determinant of hip fracture incidence and, for women of a given age, their age at menopause has, at most, a weak additional effect.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Anyone can break a hip but most hip fractures occur in elderly people. As people age, their bones gradually lose minerals and become less dense, which weakens the bones and makes them more susceptible to fracture. Because women lose bone density faster than men as they age and because women constitute the majority of the elderly, three-quarters of hip fractures occur in women. Hip fractures can cause long-term health problems and premature death. Thus, although surgical repair of a broken hip usually only requires a hospital stay of about a week, a quarter of elderly people who were living independently before their fracture have to stay in a nursing home for at least a year after their injury and a fifth of elderly people who break a hip die within the year. Most hip fractures are caused by falls. Regular exercise to improve strength and balance combined with review of medicines (to reduce side effects and interactions), regular eye examinations, and the removal of fall hazards from the home can help to prevent hip fractures in elderly people.
Why Was This Study Done?
Bone density decreases very rapidly in women immediately after menopause—the time when menstruation permanently stops—and then continues to decrease more slowly with age. Most women have their menopause in their early 50s but menopause can occur in younger women. Early menopause is thought to be a risk factor for osteoporosis (thinning of the bones) and fractures later in life but little is known about how menopause influences hip fracture risk as women age. In this prospective study (a type of study in which a group of people is followed for several years to see whether they develop a particular condition), the researchers investigate the incidence of hip fractures in relation to age, menopausal status, and age at menopause among the participants of the Million Women Study. This study, which recruited 1.3 million women aged 50–64 years who attended UK breast cancer screening clinics between 1996 and 2001, has been investigating how reproductive and lifestyle factors affect women's health.
What Did the Researchers Do and Find?
At enrollment and three years later, the study participants provided information about their menopausal status and other health and lifestyle factors likely to affect their fracture risk. From these data, the researchers identified more than half a million women who had never used hormone replacement therapy (which reduces fracture risk) and who had given complete information about their menopausal status. They then looked for statistical associations between the occurrence of a first hip fracture in these women over the next few years and their age, menopausal status, and age at menopause. Among women aged 50–54 years, postmenopausal women were twice as likely to have a hip fracture as premenopausal women. Among postmenopausal women, the incidence of hip fractures increased steeply with age and was seven times higher in 70–74-year olds than in 50–54-year olds. Women who had their menopause before age 45 had a slightly increased risk of hip fracture but any effect of age at menopause on the risk of hip fracture was small compared to the effect of age itself, and the slightly increased risk may have been due to other factors that could not be fully accounted for in the analysis.
What Do These Findings Mean?
These findings indicate that around the time of menopause, although hip fractures are rare, the risk of a fracture in postmenopausal women is twice that in premenopausal women. The findings also show that among postmenopausal women, age is the major determinant of hip fracture risk and that for women of a given age, their age at menopause has little effect on hip fracture risk. Women attending breast cancer screening clinics and completing questionnaires about their health may not be representative of the general population. Furthermore, these findings rely on women self-reporting their menopausal status accurately. Nevertheless, the results of this study suggest that clinicians advising women about hip fracture prevention should probably base their advice on the woman's age and on age-related factors such as frailty rather than on factors related to menopause. Clinicians can also now reassure elderly women who had an early menopause that their risk of hip fracture is unlikely to be higher than that of similar women who had a later menopause.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000181.
The American Academy of Orthopaedic Surgeons has detailed information about hip fractures
The US National Institute of Arthritis and Muscoloskeletal and Skin Diseases has an interactive feature called “Check up on your bones and provides detailed information about osteoporosis, including advice on fall prevention
The US Centers for Disease Control and Prevention has a fact sheet about hip fractures among older adults
MedlinePlus has links to resources about hip fracture, osteoporosis, and menopause (in English and Spanish)
More information on the Million Women Study is available
doi:10.1371/journal.pmed.1000181
PMCID: PMC2766835  PMID: 19901981

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