Recent high-throughput transcript discoveries have yielded a growing recognition of long intergenic non-coding RNAs (lincRNAs), a class of arbitrarily defined transcripts (>200 nt) that are primarily produced from the intergenic space. lincRNAs have been increasingly acknowledged for their expressional dynamics and likely functional associations with cancers. However, differential gene dosage of lincRNA genes between cancer genomes is less studied. By using the high-density Human Omni5-Quad BeadChips (Illumina), we investigated genomic copy number aberrations in a set of seven tumor-normal paired primary human mammary epithelial cells (HMECs) established from patients with invasive ductal carcinoma. This Beadchip platform includes a total of 2,435,915 SNP loci dispersed at an average interval of ~700 nt throughout the intergenic region of the human genome. We mapped annotated or putative lincRNA genes to a subset of 332,539 SNP loci, which were included in our analysis for lincRNA-associated copy number variations (CNV). We have identified 122 lincRNAs, which were affected by somatic CNV with overlapped aberrations ranging from 0.14% to 100% in length. lincRNA-associated aberrations were detected predominantly with copy number losses and preferential clustering to the ends of chromosomes. Interestingly, lincRNA genes appear to be less susceptible to CNV in comparison to both protein-coding and intergenic regions (CNV affected segments in percentage: 1.8%, 37.5%, and 60.6%, respectively). In summary, our study established a novel approach utilizing high-resolution SNP array to identify lincRNA candidates, which could functionally link to tumorigenesis, and provide new strategies for the diagnosis and treatment of breast cancer.

Background

The significant mortality associated with breast cancer (BCa) suggests a need to improve current research strategies to identify new genes that predispose women to breast cancer. Differential allele-specific expression (DASE) has been shown to contribute to phenotypic variables in humans and recently to the pathogenesis of cancer. We previously reported that nonsense-mediated mRNA decay (NMD) could lead to DASE of BRCA1/2, which is associated with elevated susceptibility to breast cancer. In addition to truncation mutations, multiple genetic and epigenetic factors can contribute to DASE, and we propose that DASE is a functional index for cis-acting regulatory variants and pathogenic mutations, and that global analysis of DASE in breast cancer precursor tissues can be used to identify novel causative alleles for breast cancer susceptibility.

Results

To test our hypothesis, we employed the Illumina® Omni1-Quad BeadChip in paired genomic DNA (gDNA) and double-stranded cDNA (ds-cDNA) samples prepared from eight BCa patient-derived normal mammary epithelial lines (HMEC). We filtered original array data according to heterozygous genotype calls and calculated DASE values using the Log ratio of cDNA allele intensity, which was normalized to the corresponding gDNA. We developed two statistical methods, SNP- and gene-based approaches, which allowed us to identify a list of 60 candidate DASE loci (DASE ≥ 2.00, P ≤ 0.01, FDR ≤ 0.05) by both methods. Ingenuity Pathway Analysis of DASE loci revealed one major breast cancer-relevant interaction network, which includes two known cancer causative genes, ZNF331 (DASE = 2.31, P = 0.0018, FDR = 0.040) and USP6 (DASE = 4.80, P = 0.0013, FDR = 0.013), and a breast cancer causative gene, DMBT1 (DASE=2.03, P = 0.0017, FDR = 0.014). Sequence analysis of a 5′ RACE product of DMBT1 demonstrated that rs2981745, a putative breast cancer risk locus, appears to be one of the causal variants leading to DASE in DMBT1.

Conclusions

Our study demonstrated for the first time that global DASE analysis is a powerful new approach to identify breast cancer risk allele(s).

Background

Previous screening trials for early detection of ovarian cancer in postmenopausal women have used the standard CA125 cut-point of 35 U/mL, the 98th percentile in this population yielding a 2% false positive rate, while the same cut-point in trials of premenopausal women results in substantially higher false positive rates. We investigated demographic and clinical factors predicting CA125 distributions, including 98th percentiles, in a large population of high-risk women participating in two ovarian cancer screening studies with common eligibility criteria and screening protocols.

Methods

Baseline CA125 values and clinical and demographic data from 3,692 women participating in screening studies conducted by the NCI-sponsored Cancer Genetics Network and Gynecologic Oncology Group were combined for this pre-planned analysis. Due to the large effect of menopausal status on CA125 levels, statistical analyses were conducted separately in pre- and postmenopausal subjects to determine the impact of other baseline factors on predicted CA125 cut-points based on the 98th percentile.

Results

The primary clinical factor affecting CA125 cut-points was menopausal status, with premenopausal women having a significantly higher cut-point of 50 U/mL while in postmenopausal subjects the standard cut-point of 35 U/mL was recapitulated. In premenopausal women, current oral contraceptive (OC) users had a cut-point of 40 U/mL.

Conclusions

To achieve a 2% false positive rate in ovarian cancer screening trials and in high-risk women choosing to be screened, the cut-point for initial CA125 testing should be personalized primarily for menopausal status (~ 50 for premenopausal women, 40 for premenopausal on OC, 35 for postmenopausal women).

Objective

The primary objective of the study was to prospectively assess quality of life (QOL) among women at increased risk of ovarian cancer who are undergoing risk-reducing salpingo-oophorectomy (RRSO) or serial screening.

Methods

Women at increased risk of ovarian cancer who were undergoing RRSO were recruited into the study. At-risk women undergoing serial screening for early detection of ovarian cancer served as a comparison group. Participants completed measures of QOL, sexual functioning, body image, depressive symptoms, and a symptom checklist at baseline (prior to surgery for women obtaining RRSO), and then at 1-month, 6-months, and 12-months post baseline.

Results

Women who underwent surgery reported poorer physical functioning, more physical role limitations, greater pain, less vitality, poorer social functioning, and greater discomfort and less satisfaction with sexual activities at 1-month assessment compared to baseline. In contrast, women undergoing screening experienced no significant decrements in QOL or sexual functioning at 1-month assessment. Most QOL deficits observed in the surgical group were no longer apparent by 6-month assessment. Women in the surgery group were more likely to report hot flashes and vaginal dryness, but over time, symptoms of vaginal discomfort decreased to a greater extent in women who had RRSO compared to women undergoing screening. No differences in body image or depressive symptoms were observed between the two groups at any time point.

Conclusions

Short-term deficits in physical functioning and other specific domains of QOL were observed following RRSO, but most women recovered baseline functioning by 6- and 12-month assessments. Issues regarding the potential impact of surgery on short-term sexual functioning should be considered and weighed carefully, particularly among younger women.

Purpose

Risk-reducing salpingo-oophorectomy (RRSO) has been widely adopted as a key component of breast and gynecologic cancer risk-reduction for women with BRCA1 and BRCA2 mutations. Despite 17% to 39% of all BRCA mutation carriers having a mutation in BRCA2, no prospective study to date has evaluated the efficacy of RRSO for the prevention of breast and BRCA-associated gynecologic (ovarian, fallopian tube or primary peritoneal) cancer when BRCA2 mutation carriers are analyzed separately from BRCA1 mutation carriers.

Patients and Methods

A total of 1,079 women 30 years of age and older with ovaries in situ and a deleterious BRCA1 or BRCA2 mutation were enrolled onto prospective follow-up studies at one of 11 centers from November 1, 1994 to December 1, 2004. Women self-selected RRSO or observation. Follow-up information through November 30, 2005, was collected by questionnaire and medical record review. The effect of RRSO on time to diagnosis of breast or BRCA-associated gynecologic cancer was analyzed using a Cox proportional-hazards model.

Results

During 3-year follow-up, RRSO was associated with an 85% reduction in BRCA1-associated gynecologic cancer risk (hazard ratio [HR] = 0.15; 95% CI, 0.04 to 0.56) and a 72% reduction in BRCA2-associated breast cancer risk (HR = 0.28; 95% CI, 0.08 to 0.92). While protection against BRCA1-associated breast cancer (HR = 0.61; 95% CI, 0.30 to 1.22) and BRCA2-associated gynecologic cancer (HR = 0.00; 95% CI, not estimable) was suggested, neither effect reached statistical significance.

Conclusion

The protection conferred by RRSO against breast and gynecologic cancers may differ between carriers of BRCA1 and BRCA2 mutations. Further studies evaluating the efficacy of risk-reduction strategies in BRCA mutation carriers should stratify by the specific gene mutated.

Summary

We examined the feasibility of home videoconferencing for providing cancer genetic education and risk information to people at-risk. Adults with possible hereditary colon or breast-ovarian cancer syndromes were offered Internet-based counselling. Participants were sent webcams and software to install on their home PCs. They watched a pre-recorded educational video and then took part in a live counselling session with a genetic counsellor. 31 participants took part in Internet counselling sessions. Satisfaction with counselling was high in all domains studied, including technical (mean 4.3 on scale from 1–5), education (mean 4.7), communication (mean 4.8), psychosocial (mean 4.1), and overall (mean 4.2). Qualitative data identified technical aspects that could be improved. All participants reported that they would recommend Internet-based counselling to others. Internet-based genetic counselling is feasible and associated with a high level of satisfaction among participants.

This paper reviews factors associated with uptake of risk-reducing salpingo-oophorectomy by women at increased hereditary risk for ovarian cancer, as well as quality of life issues following surgery. Forty one research studies identified through PubMed and PsychInfo met inclusion criteria. Older age, having had children, a family history of ovarian cancer, a personal history of breast cancer, prophylactic mastectomy, and BRCA1/2 mutation carrier status increase the likelihood of undergoing surgery. Psychosocial variables predictive of surgery uptake include greater perceived risk of ovarian cancer and cancer-related anxiety. Most women report satisfaction with their decision to undergo surgery and both lower perceived ovarian cancer risk and less cancer-related anxiety as benefits. Hormonal deprivation is the main disadvantage reported, particularly by premenopausal women who are not on hormonal replacement therapy (HRT). The evidence is mixed regarding satisfaction with the level of information provided prior to surgery, although generally women report receiving insufficient information regarding the pros and cons of HRT. These findings indicate that when designing decision aids, demographic, medical history, and psychosocial variables need to be addressed in order to facilitate quality decision making.

Based on the Cognitive-Social Health Information Processing model, we identified cognitive profiles of women at risk for breast and ovarian cancer. Prior to genetic counseling, participants (N = 171) completed a study questionnaire concerning their cognitive and affective responses to to being at genetic risk. Using cluster analysis, four cognitive profiles were generated: (a) high perceived risk/low coping; (b) low value of screening/high expectancy of cancer; (c) moderate perceived risk/moderate efficacy of prevention/low informativeness of test result; and (d) high efficacy of prevention/high coping. The majority of women in clusters one, two and three were unaffected, whereas cluster four consisted almost entirely of affected women. Women in cluster one had the highest number of affected relatives and experienced higher levels of distress than women in the other three clusters. These results highlight the need to consider the psychological profile of women undergoing genetic testing when designing counseling interventions and messages.

The CHEK2-1100delC mutation is recurrent in the population and is a moderate risk factor for breast cancer. To identify additional CHEK2 mutations potentially contributing to breast cancer susceptibility, we sequenced 248 cases with early-onset disease; functionally characterized new variants and conducted a population-based case–control analysis to evaluate their contribution to breast cancer risk. We identified 1 additional null mutation and 5 missense variants in the germline of cancer patients. In vitro, the CHEK2-H143Y variant resulted in gross protein destabilization, while others had variable suppression of in vitro kinase activity using BRCA1 as a substrate. The germline CHEK2-1100delC mutation was present among 8/1,646 (0.5%) sporadic, 2/400 (0.5%) early-onset and 3/302 (1%) familial breast cancer cases, but undetectable amongst 2,105 multiethnic controls, including 633 from the US. CHEK2-positive breast cancer families also carried a deleterious BRCA1 mutation. 1100delC appears to be the only recurrent CHEK2 mutation associated with a potentially significant contribution to breast cancer risk in the general population. Another recurrent mutation with attenuated in vitro function, CHEK2-P85L, is not associated with increased breast cancer susceptibility, but exhibits a striking difference in frequency across populations with different ancestral histories. These observations illustrate the importance of genotyping ethnically diverse groups when assessing the impact of low-penetrance susceptibility alleles on population risk. Our findings highlight the notion that clinical testing for rare missense mutations within CHEK2 may have limited value in predicting breast cancer risk, but that testing for the 1100delC variant may be valuable in phenotypically- and geographically-selected populations.

Purpose: This study was undertaken to describe cancer risk assessment practices among primary care providers (PCPs). Methods: An electronic survey was sent to PCPs affiliated with a single insurance carrier. Demographic and practice characteristics associated with cancer genetic risk assessment and testing activities were described. Latent class analysis supported by likelihood ratio tests was used to define PCP profiles with respect to the level of engagement in genetic risk assessment and referral activity based on demographic and practice characteristics. Results: 860 physicians responded to the survey (39% family practice, 29% internal medicine, 22% obstetrics/gynecology (OB/GYN), 10% other). Most respondents (83%) reported that they routinely assess hereditary cancer risk; however, only 33% reported that they take a full, three-generation pedigree for risk assessment. OB/GYN specialty, female gender, and physician access to a genetic counselor were independent predictors of referral to cancer genetics specialists. Three profiles of PCPs, based upon referral practice and extent of involvement in genetics evaluation, were defined. Conclusion: Profiles of physician characteristics associated with varying levels of engagement with cancer genetic risk assessment and testing can be identified. These profiles may ultimately be useful in targeting decision support tools and services.

MicroRNAs regulate diverse cellular processes and play an integral role in cancer pathogenesis. Genomic variation within miRNA target sites may therefore be important sources for genetic differences in cancer risk. To investigate this possibility, we mapped HapMap SNPs to putative miRNA recognition sites within genes dysregulated in estrogen receptor stratified breast tumors and used local linkage disequilibirum (LD) patterns to identify high-ranking SNPs in the Cancer Genetic Markers of Susceptibility (CGEMS) breast cancer genome wide association study (GWAS) for further testing. Two SNPs, rs1970801 and rs11097457, scoring in the top 100 from the CGEMS study, were in strong LD with rs1434536 – a SNP that resides within a miR-125b target site in the 3'UTR of the Bone Morphogenic Receptor Type 1B (BMPR1B) gene encoding a transmembrane serine/threonine kinase. We validated the CGEMS association findings for rs1970801 in an independent cohort of admixture corrected cases identified from families with multiple case histories. Subsequent association testing of rs1434536 for these cases and CGEMS controls with imputed genotypes supported the association. Furthermore, luciferase reporter assays and overexpression of miR-125b-mimics combined with quantitative RT-PCR showed that BMPR1B transcript is a direct target of miR-125b and that miR-125b differentially regulates the C and T alleles of rs1434536. These results suggest that allele-specific regulation of BMPR1B by miR-125b explains the observed disease risk. Our approach is general and can help identify and explain the mechanisms behind disease-association for alleles that affect miRNA regulation.

Recent advances in genetics have identified several genes associated with inherited susceptibility to breast and ovarian cancer and have led to the commercial availability of mutation analyses. Although the majority of cancers associated with BRCA1/2 mutations are seen in women, men with BRCA1/2 mutations are at increased risk for male breast cancer, prostate cancer, pancreatic cancer and melanoma. Limited data available on the response of men in BRCA1/2 families suggest that the majority do not pursue genetic counseling, thus they may forgo the opportunity to improve health practices and to pass on valuable cancer risk information to offspring. The patterns of relationships of men within the family and society can pose challenges to their recognition of genetic health threats and the need for preventive interventions. Genetic counselors are in a position to inform at-risk males of their genetic risk, and to help them explore their personal health options.

A key function of cancer genetics services is to provide risk information. Yet, to date there has been little consistency in the way that breast cancer risk perception has been measured. The aims of the study were to measure estimates of (i) population risk (ii) absolute risk (iii) comparative risk of developing breast cancer for Ashkenazi Jewish women, and to determine predictors of breast cancer risk perception. Of 152 women, 107 (70%) completed all questions. The mean (s.d.) estimate for population risk, absolute risk and comparative risk were 22.7% (15.9), 31.8% (20.6) and 1.9-fold (1.9), respectively. Most women over-estimated population risk. Women at population risk generally over-estimated the population risk and their own absolute risk, yet understood they are at the same risk as the population. Those with a family history understood they are at increased risk, but underestimated the extent to which their familial risk is increased. Anxiety, high estimation of population risk and lesser family history predicted over-estimation of absolute risk, while high estimation of population risk and a strong family history predicted under-estimation of comparative risk.

Background

Women with a family history of breast cancer may be at higher risk for breast cancer, but few previous studies evaluating diet and breast cancer have focused on such women. The objective of the present study was to determine whether diet, a modifiable risk factor, is related to breast density among women at high genetic risk for breast cancer.

Methods

Women with at least one first-degree or second-degree relative with breast cancer or ovarian cancer participating in the Fox Chase Cancer Center Family Risk Assessment Program completed health history and food frequency questionnaires and received standard screening mammograms. Cranial–caudal mammographic images were classified into the four Breast Imaging Reporting and Data System categories ranging from 'entirely fatty' to 'extremely dense'. Logistic regression analysis using proportional odds models for polychotomous outcomes provided estimates of odds ratios for having a higher category versus a lower category of breast density.

Results

Among 157 high-risk women, breast density was inversely associated with vitamin D intake (odds ratio for third tertile versus first tertile, 0.5; 95% confidence interval, 0.2–1.0). In contrast, intakes above the median level for protein (odds ratio, 3.0; 95% confidence interval, 1.3–6.9) and above the median level for animal protein (odds ratio, 4.3; 95% confidence interval, 1.8–10.3) were associated with higher breast density, but only among women whose family history did not reflect a known familial cancer syndrome or a breast cancer predisposition gene.

Conclusion

For women with a strong family history that was not associated with known cancer syndromes, dietary factors may be associated with breast density, a strong predictor of breast cancer risk. Since women with strong family history are often very motivated to change their lifestyle habits, further studies are needed to confirm whether changes in diet will change the breast density and the subsequent onset of breast cancer in these women.

Background

BRCA1 and BRCA2 mutation carriers have a lifetime breast cancer risk of 40% to 80%, suggesting the presence of risk modifiers. We previously identified significant associations in genetic variants in the insulin-like growth factor (IGF) signaling pathway. Here, we investigate additional IGF signaling genes as risk modifiers for breast cancer development in BRCA carriers.

Methods

A cohort of 1,019 BRCA1 and 500 BRCA2 mutation carriers were genotyped for 99 single-nucleotide polymorphisms (SNP) in 13 genes. Proportional hazards regression was used to model time from birth to diagnosis of breast cancer for BRCA1 and BRCA2 carriers separately. For linkage disequilibrium (LD) blocks with multiple SNPs, an additive genetic model was used. For an SNP analysis, no additivity assumptions were made.

Results

Significant associations were found between risk of breast cancer and LD blocks in IGF2 for BRCA1 and BRCA2 mutation carriers (global P values of 0.009 for BRCA1 and 0.007 for BRCA2), HTRA1 for BRCA1 carriers (global P value of 0.005), and MMP3 for BRCA2 carriers (global P = 0.0000007 for BRCA2).

Conclusions

We identified significant associations of genetic variants involved in IGF signaling. With the known interaction of BRCA1 and IGF signaling and the loss of PTEN in a majority of BRCA1 tumors, this suggests that signaling through AKT may modify breast cancer risk in BRCA1 carriers.

Impact

These results suggest potential avenues for future research targeting the IGF signaling pathway in modifying risk in BRCA1and BRCA2 mutation carriers.

Inherited BRCA1 mutations confer elevated breast cancer risk. Recent studies have identified genes that encode proteins that interact with BRCA1 as modifiers of BRCA1-associated breast cancer. We evaluated a comprehensive set of genes that encode most known BRCA1 interactors to evaluate the role of these genes as modifiers of cancer risk. A cohort of 2,825 BRCA1 mutation carriers was used to evaluate the association of haplotypes at ATM, BRCC36, BRCC45 (BRE), BRIP1 (BACH1/FANCJ), CTIP, ABRA1 (FAM175A), MERIT40, MRE11A, NBS1, PALB2 (FANCN), RAD50, RAD51, RAP80, TOPBP1 and time to breast and ovarian cancer diagnosis. False Discovery Rate (FDR) adjusted p-value for overall association of haplotypes (pFDR) with breast cancer were identified at ATM (pFDR =0.029), BRCC45 (pFDR=0.0.19), BRIP1 (pFDR =0.008), CTIP (pFDR =0.017), MERIT40 (pFDR =0.019), NBS1 (pFDR=0.003), RAD50 (pFDR=0.014), and TOPBP1 (pFDR =0.011) and were associated with breast cancer risk. Haplotypes at ABRA1 (pFDR=0.007), BRCC45 (pFDR=0.016 and pFDR=0.005 in two haplotype blocks) and RAP80 (pFDR<0.001) were associated with ovarian cancer risk. Overall, the data suggest that genomic variation at multiple loci that encode proteins that interact biologically with BRCA1 are associated with modified breast cancer and ovarian cancer risk in women who carry BRCA1 mutations.

Inherited BRCA1 mutations confer elevated breast cancer risk. Recent studies have identified genes that encode proteins that interact with BRCA1 as modifiers of BRCA1-associated breast cancer. We evaluated a comprehensive set of genes that encode most known BRCA1 interactors to evaluate the role of these genes as modifiers of cancer risk. A cohort of 2,825 BRCA1 mutation carriers was used to evaluate the association of haplotypes at ATM, BRCC36, BRCC45 (BRE), BRIP1 (BACH1/FANCJ), CTIP, ABRA1 (FAM175A), MERIT40, MRE11A, NBS1, PALB2 (FANCN), RAD50, RAD51, RAP80, TOPBP1 and time to breast and ovarian cancer diagnosis. False Discovery Rate (FDR) adjusted p-value for overall association of haplotypes (pFDR) with breast cancer were identified at ATM (pFDR =0.029), BRCC45 (pFDR=0.0.19), BRIP1 (pFDR =0.008), CTIP (pFDR =0.017), MERIT40 (pFDR =0.019), NBS1 (pFDR=0.003), RAD50 (pFDR=0.014), and TOPBP1 (pFDR =0.011) and were associated with breast cancer risk. Haplotypes at ABRA1 (pFDR=0.007), BRCC45 (pFDR=0.016 and pFDR=0.005 in two haplotype blocks) and RAP80 (pFDR<0.001) were associated with ovarian cancer risk. Overall, the data suggest that genomic variation at multiple loci that encode proteins that interact biologically with BRCA1 are associated with modified breast cancer and ovarian cancer risk in women who carry BRCA1 mutations.

Purpose

BRCA1/2 test disclosure has, historically, been conducted in-person by genetics professionals. Given increasing demand for, and access to, genetic testing, interest in telephone and Internet genetic services, including disclosure of test results, has increased.

Methods

Semi-structured interviews with genetic counselors were conducted to determine interest in, and experiences with telephone disclosure of BRCA1/2 test results. Descriptive data are summarized with response proportions.

Results

194 genetic counselors completed self-administered surveys via the web. Although 98% had provided BRCA1/2 results by telephone, 77% had never provided pre-test counseling by telephone. Genetic counselors reported perceived advantages and disadvantages to telephone disclosure. Thirty-two percent of participants described experiences that made them question this practice. Genetic counselors more frequently reported discomfort with telephone disclosure of a positive result or variant of uncertain significance (p<0.01) than other results. Overall, 73% of participants reported interest in telephone disclosure.

Conclusion

Many genetic counselors have provided telephone disclosure, however, most, infrequently. Genetic counselors identify potential advantages and disadvantages to telephone disclosure, and recognize the potential for testing and patient factors to impact patient outcomes. Further research evaluating the impact of testing and patient factors on cognitive, affective, social and behavioral outcomes of alternative models of communicating genetic information is warranted.

Introduction

Selecting women affected with breast cancer who are most likely to carry a germline mutation in BRCA1 and applying the most appropriate test methodology remains challenging for cancer genetics services. We sought to test the value of selecting women for BRCA1 mutation testing on the basis of family history and/or breast tumour morphology criteria as well as the value of testing for large genomic alterations in BRCA1.

Methods

We studied women participating in the Breast Cancer Family Registry (BCFR), recruited via population-based sampling, who had been diagnosed with breast cancer before the age of 40 years who had a strong family history of breast or ovarian cancer (n = 187) and/or a first primary breast tumour with morphological features consistent with carrying a BRCA1 germline mutation (n = 133; 37 met both criteria). An additional 184 women diagnosed before the age of 40 years who had a strong family history of breast or ovarian cancer and who were not known to carry a germline BRCA1 mutation were selected from among women who had been recruited into the BCFR from clinical genetics services. These 467 women had been screened for BRCA1 germline mutations, and we expanded this testing to include a screen for large genomic BRCA1 alterations using Multiplex Ligation-dependent Probe Amplification.

Results

Twelve large genomic BRCA1 alterations were identified, including 10 (4%) of the 283 women selected from among the population-based sample. In total, 18 (12%), 18 (19%) and 16 (43%) BRCA1 mutations were identified in the population-based groups selected on the basis of family history only (n = 150), the group selected on the basis of tumour morphology only (n = 96) and meeting both criteria (n = 37), respectively.

Conclusions

Large genomic alterations accounted for 19% of all BRCA1 mutations identified. This study emphasises the value of combining information about family history, age at diagnosis and tumour morphology when selecting women for germline BRCA1 mutation testing as well as including a screen for large genomic alterations.

Risk-reducing salpingo-oophorectomy (RRSO) is widely used for cancer risk reduction in BRCA1 or BRCA2 (BRCA1/2) mutation carriers. Occult ovarian/fallopian tube cancers (OOC) detected at the time of RRSO have been reported in several studies with wide variability in reported prevalence. We estimated the prevalence of OOC in a prospective cohort of 647 BRCA1/2 mutation carriers from 18 centers (PROSE consortium) who under-went RRSO between 2001 and 2008. OOC was detected in 16 of 647 women (2.5%). The mean age at RRSO was 51.7 in those with OOC versus 46.6 in those without OOC (P = 0.017). Twelve of the 16 OOCs (75%) were diagnosed in women with BRCA1 mutations. Thirty-eight percent of women with OOC had stage 1 cancer versus none of the women in the PROSE database diagnosed with ovarian cancer outside of screening. Among 385 women (60%) in whom pathology reports were available for central review, 246 (64%) RRSOs were performed at participating PROSE centers while 139 (36%) were performed at local sites. Ovarian and fallopian tube tissues removed at major genetics referral centers were significantly more likely to have been examined in toto compared to specimens obtained at non-referral centers (75% vs. 30%, P < 0.001). Our results confirm that OOC may be found at the time of RRSO in BRCA1/2 mutation carriers and suggest that OOC are of a more favorable stage than cancers found outside RRSO. An unacceptably high proportion of pathologic examinations did not adequately examine ovaries and fallopian tubes obtained at RRSO.

Context

Risk-reducing mastectomy (RRM) and salpingo-oophorectomy (RRSO) are widely used by carriers of BRCA1 or BRCA2 mutations to reduce their risks of breast and ovarian cancer.

Objectives

To estimate risk and mortality reduction stratified by mutation and prior cancer status.

Design

A prospective multi-center cohort study was used to assess the relationship of RRM and RRSO on cancer outcomes.

Setting

Twenty-two clinical and research genetics centers in Europe and North America.

Participants

2,482 women identified 1974-2008 and followed until the end of 2009 who tested positive for BRCA1 or BRCA2 mutations.

Interventions

257 (10%) underwent RRM and 993 (40%) underwent RRSO.

Main outcomes measures

Breast and ovarian cancer risk; cancer-specific and overall mortality.

Results

No breast cancers were diagnosed in women with RRM compared to 7% of women without RRM. In women who underwent RRSO, 1.1% were subsequently diagnosed with ovarian cancer, 11.4% were subsequently diagnosed with breast cancer, and 3% subsequently died from any cause, compared with 5.8% ovarian cancer, 19.2% breast cancer, and 10% overall mortality in women who did not undergo RRSO. RRSO was associated with a lower risk of ovarian cancer in those with (Hazard Ratio (HR) 0.31, 95% CI 0.12-0.82) and without a prior breast cancer (HR 0.15, 0.04-0.63), and a lower risk of first breast cancer in both BRCA1 (HR 0.63, 0.41-0.96) and BRCA2 (HR 0.36, 0.16-0.82) mutation carriers. RRSO was associated with a reduction in all-cause (HR 0.40, 0.26-0.61), breast cancer-specific (HR 0.44, 0.26-0.76), and ovarian cancer-specific (HR 0.25, 0.08-0.75) mortality.

Conclusions

Among a cohort of women with BRCA1 and BRCA2 mutations, the use of RRM was associated with a lower risk of breast cancer, and RRSO was associated with a lower risk of ovarian cancer, first breast cancer, and overall, breast-, and ovarian-cancer specific mortality.

Inherited BRCA1/2 mutations confer elevated ovarian cancer (OvCa) risk. Knowledge of factors that can improve OvCa risk assessment in BRCA1/2 mutation carriers is important because no effective early detection for OvCas exists. A cohort of 1,575 BRCA1 and 856 BRCA2 mutation carriers was used to evaluate SNPs and haplotypes at ATM, BARD1, BRIP1, CTIP, MRE11, NBS1, RAD50, RAD51, and TOPBP1 in OvCa risk. In BRCA1 carriers, no associations were observed with ATM, BARD1, CTIP, RAD50, RAD51, or TOPBP1. At BRIP1, an association was observed for one haplotype with a multiple testing corrected p-value (pcorr)=0.012, although no individual haplotype was significant. At MRE11, statistically significant associations were observed for one haplotype (pcorr=0.007). At NBS1, we observed a pcorr=0.024 for haplotypes. In BRCA2 carriers, no associations were observed with CTIP, NBS1, RAD50, or TOPBP1. Rare haplotypes at ATM (pcorr=0.044) and BARD1 (pcorr=0.012) were associated with OvCa risk. At BRIP1, two common haplotypes were significantly associated with OvCa risk (pcorr=0.011). At MRE11, we observed a significant haplotype association (pcorr=0.012), and at RAD51, one common haplotype was significantly associated with OvCa risk (pcorr=0.026). Variants in genes that interact biologically with BRCA1 and/or BRCA2 may be associated with modified OvCa risk in women who carry BRCA1/2 mutations.

The Breast Cancer Family Registry is a resource for interdisciplinary and translational studies of the genetic epidemiology of breast cancer. This resource is available to researchers worldwide for collaborative studies. Herein, we report the results of testing for germline mutations in BRCA1 and BRCA2. We have tested 4,531 probands for mutations in BRCA1 and 4,084 in BRCA2. Deleterious mutations in BRCA1 and BRCA2 were identified for 9.8% of probands tested [233/4,531 (5.1%) for BRCA1 and 193/4,084 (4.7%) for BRCA2]. Of 1,385 Ashkenazi Jewish women tested for only the three founder mutations, 17.4% carried a deleterious mutation. In total, from the proband and subsequent family testing, 1,360 female mutation carriers (788 in BRCA1, 566 in BRCA2, 6 in both BRCA1 and BRCA2) have been identified. The value of the resource has been greatly enhanced by determining the germline BRCA1 and BRCA2 mutation statuses of nearly 6,000 probands.

Introduction

Women who carry mutations in BRCA1 and BRCA2 have a substantially increased risk of developing breast cancer as compared with the general population. However, risk estimates range from 20 to 80%, suggesting the presence of genetic and/or environmental risk modifiers. Based on extensive in vivo and in vitro studies, one important pathway for breast cancer pathogenesis may be the insulin-like growth factor (IGF) signaling pathway, which regulates both cellular proliferation and apoptosis. BRCA1 has been shown to directly interact with IGF signaling such that variants in this pathway may modify risk of cancer in women carrying BRCA mutations. In this study, we investigate the association of variants in genes involved in IGF signaling and risk of breast cancer in women who carry deleterious BRCA1 and BRCA2 mutations.

Methods

A cohort of 1,665 adult, female mutation carriers, including 1,122 BRCA1 carriers (433 cases) and 543 BRCA2 carriers (238 cases) were genotyped for SNPs in IGF1, IGF1 receptor (IGF1R), IGF1 binding protein (IGFBP1, IGFBP2, IGFBP5), and IGF receptor substrate 1 (IRS1). Cox proportional hazards regression was used to model time from birth to diagnosis of breast cancer for BRCA1 and BRCA2 carriers separately. For linkage disequilibrium (LD) blocks with multiple SNPs, an additive genetic model was assumed; and for single SNP analyses, no additivity assumptions were made.

Results

Among BRCA1 carriers, significant associations were found between risk of breast cancer and LD blocks in IGF1R (global P = 0.011 for LD block 2 and global P = 0.012 for LD block 11). Among BRCA2 carriers, an LD block in IGFBP2 (global P = 0.0145) was found to be associated with the time to breast cancer diagnosis. No significant LD block associations were found for the other investigated genes among BRCA1 and BRCA2 carriers.

Conclusions

This is the first study to investigate the role of genetic variation in IGF signaling and breast cancer risk in women carrying deleterious mutations in BRCA1 and BRCA2. We identified significant associations in variants in IGF1R and IRS1 in BRCA1 carriers and in IGFBP2 in BRCA2 carriers. Although there is known to be interaction of BRCA1 and IGF signaling, further replication and identification of causal mechanisms are needed to better understand these associations.

Previously, a candidate gene linkage approach on brother pairs affected with prostate cancer identified a locus of prostate cancer susceptibility at D3S1234 within the fragile histidine triad gene (FHIT), a tumor suppressor that induces apoptosis. Subsequent association tests on 16 SNPs spanning approximately 381 kb surrounding D3S1234 in Americans of European descent revealed significant evidence of association for a single SNP within intron 5 of FHIT. In the current study, re-sequencing and genotyping within a 28.5 kb region surrounding this SNP further delineated the association with prostate cancer risk to a 15 kb region. Multiple SNPs in sequences under evolutionary constraint within intron 5 of FHIT defined several related haplotypes with an increased risk of prostate cancer in European-Americans. Strong associations were detected for a risk haplotype defined by SNPs 138543, 142413, and 152494 in all cases (Pearson's χ2 = 12.34, df 1, P = 0.00045) and for the homozygous risk haplotype defined by SNPs 144716, 142413, and 148444 in cases that shared 2 alleles identical by descent with their affected brothers (Pearson's χ2 = 11.50, df 1, P = 0.00070). In addition to highly conserved sequences encompassing SNPs 148444 and 152413, population studies revealed strong signatures of natural selection for a 1 kb window covering the SNP 144716 in two human populations, the European American (π = 0.0072, Tajima's D = 3.31, 14 SNPs) and the Japanese (π = 0.0049, Fay & Wu's H = 8.05, 14 SNPs), as well as in chimpanzees (Fay & Wu's H = 8.62, 12 SNPs). These results strongly support the involvement of the FHIT intronic region in an increased risk of prostate cancer.