PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-18 (18)
 

Clipboard (0)
None

Select a Filter Below

Journals
more »
Year of Publication
Document Types
1.  Serum calcium and risk of gastrointestinal cancer in the Swedish AMORIS study 
BMC Public Health  2013;13:663.
Background
Observational studies have indicated that high calcium intake may prevent colorectal cancer, but as for randomized trials the results are inconclusive. Meanwhile, limited data on the link between serum calcium and cancer risk is available. We investigated the relation between serum calcium and risk of different gastrointestinal cancers in a prospective study.
Methods
A cohort based on 492,044 subjects with baseline information on calcium (mmol/L) and albumin (g/L) was selected from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study. Multivariable Cox proportional hazard models were used to analyse associations between standardised levels, quartiles and age/sex-specific categories of serum calcium and risk of oesophageal, stomach, colon, rectal cancer and also colorectal cancer combined, while taking into account serum albumin and other comorbidities.
Results
During 12 years of follow-up, we identified 323 incident oesophageal cancers, 782 stomach cancers, 2519 colon cancers, and 1495 rectal cancers. A positive association was found between albumin-adjusted serum calcium and risk of oesophageal [HR: 4.82 (95% CI: 2.07 – 11.19) for high compared to normal age-specific calcium levels] and colon cancer [e.g. HR: 1.07 (95% CI: 1.00 – 1.14) for every SD increase of calcium] as well as colorectal cancer [e.g. HR: 1.06 (95% CI: 1.02-1.11) for every SD increase of calcium] in women. In men there were similar but weaker non-statistically significant trends.
Conclusion
The positive relation between serum calcium, oesophageal cancer and colorectal cancer calls for further studies including calcium regulators to evaluate whether there is a true link between calcium metabolism and development of gastrointestinal cancer.
doi:10.1186/1471-2458-13-663
PMCID: PMC3729677  PMID: 23866097
Gastrointestinal cancer; Calcium; Albumin
2.  Prostate Cancer Imaging Trends After a Nationwide Effort to Discourage Inappropriate Prostate Cancer Imaging 
Background
Reducing inappropriate use of imaging to stage incident prostate cancer is a challenging problem highlighted recently as a Physician Quality Reporting System quality measure and by the American Society of Clinical Oncology and the American Urological Association in the Choosing Wisely campaign. Since 2000, the National Prostate Cancer Register (NPCR) of Sweden has led an effort to decrease national rates of inappropriate prostate cancer imaging by disseminating utilization data along with the latest imaging guidelines to urologists in Sweden. We sought to determine the temporal and regional effects of this effort on prostate cancer imaging rates.
Methods
We performed a retrospective cohort study among men diagnosed with prostate cancer from the NPCR from 1998 to 2009 (n = 99 879). We analyzed imaging use over time stratified by clinical risk category (low, intermediate, high) and geographic region. Generalized linear models with a logit link were used to test for time trend.
Results
Thirty-six percent of men underwent imaging within 6 months of prostate cancer diagnosis. Overall, imaging use decreased over time, particularly in the low-risk category, among whom the imaging rate decreased from 45% to 3% (P < .001), but also in the high-risk category, among whom the rate decreased from 63% to 47% (P < .001). Despite substantial regional variation, all regions experienced clinically and statistically (P < .001) significant decreases in prostate cancer imaging.
Conclusions
A Swedish effort to provide data on prostate cancer imaging use and imaging guidelines to clinicians was associated with a reduction in inappropriate imaging over a 10-year period, as well as slightly decreased appropriate imaging in high-risk patients. These results may inform current efforts to promote guideline-concordant imaging in the United States and internationally.
doi:10.1093/jnci/djt175
PMCID: PMC3760779  PMID: 23853055
3.  A quasi-experimental study of maternal smoking during pregnancy and offspring academic achievement 
Child development  2010;81(1):80-100.
Maternal smoking during pregnancy (SDP) is associated with lower academic achievement in offspring. The current study, which was based on all births in Sweden from 1983 through 1991, explored the possible causal processes underlying the association between SDP and offspring school grades and a standardized assessment of mathematic proficiency at age 15. The analyses compared relatives who varied in their exposure to SDP and who varied in their genetic relatedness. Although SDP was statistically associated with academic achievement when comparing unrelated individuals, the results suggest that SDP does not cause poorer academic performance, as full siblings differentially exposed to SDP did not differ in their academic scores. The pattern of results suggests that genetic factors shared by parents and their offspring explain significant variance in why offspring opposed to SDP have lower levels of academic achievement. Nevertheless, SDP impacts pregnancy-related outcomes. Reducing SDP, therefore, remains a major public health issue.
doi:10.1111/j.1467-8624.2009.01382.x
PMCID: PMC3656473  PMID: 20331655
4.  Maternal Smoking During Pregnancy and Intellectual Performance in Young Adult Swedish Male Offspring 
SUMMARY
Smoking during pregnancy has been linked to an increased risk of several adverse birth outcomes. Associations with deficits in cognitive development have also been suggested. It is unclear if these associations are due to genetic and/or environmental confounding. In a population-based Swedish cohort study on 205 777 singleton males born to Nordic mothers between 1983 and 1988, we examined the association between maternal smoking during pregnancy and the risk of poor intellectual performance in young adult male offspring. In the cohort analyses, the risk of poor intellectual performance was increased in sons of smoking mothers compared to sons of non-smokers. Stratifying for maternal smoking habits across two pregnancies, there was an increased risk of poor intellectual performance for both sons if the mother was only smoking in the first pregnancy, but in neither son if the mother was only smoking in the second pregnancy. The effect of smoking during pregnancy on intellectual performance was not present when the association was evaluated within sibling pairs. Thus, the association between prenatal smoking exposure and offspring risk of low intellectual performance appears to be completely confounded by familial (genetic and early environmental) factors.
doi:10.1111/j.1365-3016.2009.01073.x
PMCID: PMC3653250  PMID: 20078833
5.  Serum Glucose and Fructosamine in Relation to Risk of Cancer 
PLoS ONE  2013;8(1):e54944.
Background
Impaired glucose metabolism has been linked with increased cancer risk, but the association between serum glucose and cancer risk remains unclear. We used repeated measurements of glucose and fructosamine to get more insight into the association between the glucose metabolism and risk of cancer.
Methods
We selected 11,998 persons (>20 years old) with four prospectively collected serum glucose and fructosamine measurements from the Apolipoprotein Mortality Risk (AMORIS) study. Multivariate Cox proportional hazards regression was used to assess standardized log of overall mean glucose and fructosamine in relation to cancer risk. Similar analyses were performed for tertiles of glucose and fructosamine and for different types of cancer.
Results
A positive trend was observed between standardized log overall mean glucose and overall cancer risk (HR = 1.08; 95% CI: 1.02–1.14). Including standardized log fructosamine in the model resulted in a stronger association between glucose and cancer risk and aninverse association between fructosamine and cancer risk (HR = 1.17; 95% CI: 1.08–1.26 and HR: 0.89; 95% CI: 0.82–0.96, respectively). Cancer risks were highest among those in the highest tertile of glucose and lowest tertile of fructosamine. Similar findings were observed for prostate, lung, and colorectal cancer while none observed for breast cancer.
Conclusion
The contrasting effect between glucose, fructosamine, and cancer risk suggests the existence of distinct groups among those with impaired glucose metabolism, resulting in different cancer risks based on individual metabolic profiles. Further studies are needed to clarify whether glucose is a proxy of other lifestyle-related or metabolic factors.
doi:10.1371/journal.pone.0054944
PMCID: PMC3556075  PMID: 23372798
6.  Gamma-glutamyl transferase and C-reactive protein as alternative markers of metabolic abnormalities and their associated comorbidites: a prospective cohort study 
Background: Recent studies suggested that gamma-glutamyl transferase (GGT) and C-reactive protein (CRP) are good markers of metabolic abnormalities. We assessed the link between GGT, CRP and common metabolic abnormalities, as well their link to related diseases, such as cancer and cardiovascular disease (CVD). Methods: We selected 333,313 subjects with baseline measurements of triglycerides (TG), total cholesterol (TC), glucose, GGT and CRP in the Swedish AMORIS study. Baseline measurement of BMI was available for 63,900 persons and 77,944 had baseline measurements of HDL. Pearson correlation coefficients between CRP, GGT, and metabolic components (TG, HDL, BMI and TC) were calculated. To investigate the combined effect of GGT and CRP we created a score ranging from 0 to 6 and used Cox proportional hazard models to evaluate its association with CVD and cancer. Results: 21,216 individuals developed cancer and 47,939 CVD. GGT and TG had the strongest correlation (r=0.22). An increased risk of cancer was identified with elevated levels of GGT or CRP or both markers (GGT-CRP score ≥3); the greatest risk of cancer was found when GGT-CRP score = 6 (HR: 1.40 (95%CI: 1.31-1.48) and 1.60 (1.47-1.76) compared to GGT-CRP score = 0, respectively). Conclusion: While GGT and CRP have been shown to be associated with metabolic abnormalities previously, their association to the components investigated in this study was limited. Results did demonstrate that these markers were predictive of associated diseases, such as cancer.
PMCID: PMC3508539  PMID: 23205179
GGT; CRP; metabolic abnormalities; cardiovascular disease; cancer
7.  Social differences in lung cancer management and survival in South East England: a cohort study 
BMJ Open  2012;2(3):e001048.
Objective
To examine possible social variations in lung cancer survival and assess if any such gradients can be attributed to social differences in comorbidity, stage at diagnosis or treatment.
Design
Population-based cohort identified in the Thames Cancer Registry.
Setting
South East England.
Participants
15 582 lung cancer patients diagnosed between 2006 and 2008.
Main outcome measures
Stage at diagnosis, surgery, radiotherapy, chemotherapy and survival.
Results
The likelihood of being diagnosed as having early-stage disease did not vary by socioeconomic quintiles (p=0.58). In early-stage non-small-cell lung cancer, the likelihood of undergoing surgery was lowest in the most deprived group. There were no socioeconomic differences in the likelihood of receiving radiotherapy in stage III disease, while in advanced disease and in small-cell lung cancer, receipt of chemotherapy differed over socioeconomic quintiles (p<0.01). In early-stage disease and following adjustment for confounders, the HR between the most deprived and the most affluent group was 1.24 (95% CI 0.98 to 1.56). Corresponding estimates in stage III and advanced disease or small-cell lung cancer were 1.16 (95% CI 1.01 to 1.34) and 1.12 (95% CI 1.05 to 1.20), respectively. In early-stage disease, the crude HR between the most deprived and the most affluent group was approximately 1.4 and constant through follow-up, while in patients with advanced disease or small-cell lung cancer, no difference was detectable after 3 months.
Conclusion
We observed socioeconomic variations in management and survival in patients diagnosed as having lung cancer in South East England between 2006 and 2008, differences which could not fully be explained by social differences in stage at diagnosis, co-morbidity and treatment. The survival observed in the most affluent group should set the target for what is achievable for all lung cancer patients, managed in the same healthcare system.
Article summary
Article focus
Social differences in management and survival in lung cancer patients.
Particular focus on possible social variations in lung cancer survival and assess if any such gradients can be attributed to social differences in co-morbidity, stage at diagnosis or treatment.
Key messages
There were no detectable socioeconomic differences in stage at diagnosis among lung cancer patients in South East England between 2006 and 2008.
Socioeconomic differences in lung cancer management and survival existed. The observed inequalities in survival could not fully be explained by social differences in stage at diagnosis, co-morbidity and treatment factors.
In early-stage disease, social gradients in survival existed throughout follow-up, whereas in advanced disease, variations in survival were confined to the period immediately after diagnosis.
Strengths and limitations of this study
Strengths included the population-based cohort design. The material at hand allowed analyses that accounted for co-morbidity, stage at diagnosis and treatment factors.
Limitations included the absence of data on performance status, forced expiratory volume, smoking history and lifestyle factors.
doi:10.1136/bmjopen-2012-001048
PMCID: PMC3367157  PMID: 22637374
8.  Lipid profiles and the risk of endometrial cancer in the Swedish AMORIS study 
Background
While the association between obesity and endometrial cancer (EC) is well established, the underlying mechanisms require further study. We assessed possible links between lipid profiles and EC risk, while also taking into account BMI, parity, and menopausal status at baseline.
Methods
Using the information available from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study we created a cohort of 225,432 women with baseline values for glucose, triglycerides (TG), and total cholesterol (TC). Two subgroups of 31,792 and 26,317 had, in addition, baseline measurements of HDL, LDL, apolipoprotein A-I and apoB and BMI, respectively. We used Multivariate Cox proportional hazards models to analyze quartiles and dichotomized values of these lipid components for a link to EC risk.
Results
During mean follow-up of 12 years (SD: 4.15), 1,144 persons developed endometrial cancer. A statistically significant association was found between TG and EC risk when using both quartiles and a clinical cut-off (Hazard Ratio (HR): 1.10 (95%CI: 0.88-1.37), 1.34 (1.09-1.63), and 1.57 (1.28-1.92)) for the 2nd, 3rd, and 4th quartile, compared to the 1st, with P-value for trend: <0.001). The association remained after exclusion of the first three years of follow-up. Also total cholesterol and TG/HDL ratio were positively associated with EC risk, but no link was found for the other lipid components studied.
Conclusion
This detailed analysis of lipid components showed a consistent relation between TG levels and EC risk. Future research should continue to analyze the metabolic pathway and its relation to EC risk, as a pathway to further understand the relation of obesity and disease.
PMCID: PMC3376923  PMID: 22724049
Lipid profiles; risk factor; endometrial cancer; Swedish AMORIS study
9.  Biomarker-based score to predict mortality in persons aged 50 years and older: a new approach in the Swedish AMORIS study 
Background
Management of frailty is the cornerstone of geriatric medicine, but there remains a need to identify biomarkers that can predict early death, and thereby lead to effective clinical interventions. We aimed to study the combination of C-reactive protein (CRP), albumin, gamma-glutamyl transferase (GGT), and HDL to predict mortality.
Methods
A total of 44,457 persons aged 50+ whose levels of CRP, albumin, GGT, and HDL were measured at baseline were selected from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study. A mortality score, ranging from 0 to 4, was created by adding the number of markers with abnormal values according to the clinical cut-off (CRP > 10 mg/L, albumin < 35 mg/L, GGT > 36 kU/L, HDL < 1.04 mmol/L). Mortality was studied with multivariate Cox proportional hazards models.
Results
2,245 persons died from cancer, 3,276 from circulatory disease, and 1,860 from other causes. There was a positive trend between mortality score and all-cause mortality as well as cancer and circulatory disease-specific death (e.g. HR for all-cause mortality: 1.39 (95%CI: 1.32-1.46), 2.04 (1.89-2.21), and 3.36 (2.87-3.93), for score=1, 2, and 3+, compared to score=0). Among cancer patients with no other co-morbidities (n=1,955), there was a positive trend between the score and mortality (HR: 1.24 (95%CI: 1.0.-1.49), 2.38 (95%CI: 1.76-3.22), and 5.47 (95%CI: 2.98-10.03) for score=1, 2, and 3+ compared to score=0).
Conclusions
By combining biomarkers of different mechanisms contributing to patient frailty, we found a strong marker for mortality in persons aged 50+. Elevated risks among cancer patients with no other co-morbidities prior to biomarker assessment call for validation in other cohorts and testing of different combinations and cut-offs than those used here, in order to aid decision-making in treatment of older cancer patients.
PMCID: PMC3316450  PMID: 22493753
Frailty; mortality; albumin; HDL-cholesterol; C-reactive protein; gamma-glutamyltransferase
10.  Birth spacing and maternal risk of invasive epithelial ovarian cancer in a Swedish nationwide cohort 
Cancer causes & control : CCC  2008;19(10):1131-1137.
Objective
Pregnancies reduce the risk of ovarian cancer and, among multiparous women, levels of circulating progesterone might be higher during pregnancies with wider birth spacing. We hypothesized that childbirth with wider birth spacing might reduce maternal risk of invasive epithelial ovarian cancer more than births with narrower spacing.
Methods
We conducted a case-control study nested in a nationwide cohort of Swedish women from 1961 to 2001. We selected five individually age-matched controls for each case of invasive epithelial ovarian cancer and analysis for the effect of birth spacing was performed for 5,341 cases and 29,047 controls. We applied unconditional logistic regression analyses adjusting for age, ages at childbirth, educational level, area of residence, and gender of offspring.
Results
Relative risk of invasive epithelial ovarian cancer associated with each one-year increase in average birth spacing is 1.00 (95% CI=0.98–1.01) among all women and 0.99 (0.98–1.01) among those born before 1935 and less likely to have used oral contraceptives. Further analyses on the biparous and triparous women did not find a consistent association between birth spacing and the risk of ovarian cancer.
Conclusions
Birth spacing is unlikely to be a major determinant underlying the protective effects of childbirth on ovarian cancer risk.
doi:10.1007/s10552-008-9178-x
PMCID: PMC3221393  PMID: 18509730
Birth spacing; Invasive epithelial ovarian cancer; Progesterone
11.  Association between levels of C-reactive protein and leukocytes and cancer: Three repeated measurements in the Swedish AMORIS study 
Objective
To study levels of C-reactive protein (CRP) and leukocytes, as inflammatory markers, in the context of cancer risk.
Methods
From the Apolipoprotein MOrtality RISk (AMORIS) study, we selected 102,749 persons with one measurement and 9,273 persons with three repeated measurements of CRP and leukocytes. Multivariate Cox proportional hazards regression was applied to categories of CRP (<10, 10-15, 15-25, 25-50, >50 g/L) and quartiles of leukocytes. An Inflammation-based Predictive Score (IPS) indicated whether someone had CRP levels >10mg/L combined with leukocytes >10×109/L. Reverse causality was assessed by excluding those with <3, 5, or 7 years of follow-up. To analyze repeated measurements of CRP and leukocytes the repeated IPS (IPSr) was calculated by adding the IPS of each measurement.
Results
In the cohort with one measurement, there was a positive trend between CRP and cancer, with the lowest category being the reference: 0.99 (0.92-1.06), 1.28 (1.11-1.47), 1.27 (1.09-1.49), 1.22 (1.01-1.48) for the 2nd to 5th categories, respectively. This association disappeared when excluding those with follow-up <3, 5 or 7 years. The association between leukocytes and cancer was slightly stronger. In the cohort with repeated measurements the IPSr was strongly associated with cancer risk: 1.87 (1.33-2.63), 1.51 (0.56-4.06), 4.46 (1.43-13.87) for IPSr =1, 2, and 3, compared to IPSr =0. The association remained after excluding those with follow-up <1 year.
Conclusions and impact
Our large prospective cohort study adds evidence for a link between inflammatory markers and cancer risk by using repeated measurements and ascertaining reverse causality.
doi:10.1158/1055-9965.EPI-10-1190
PMCID: PMC3078551  PMID: 21297038
cancer; C-reactive protein; leukocytes; Sweden
12.  Breast Cancer, Sickness Absence, Income and Marital Status. A Study on Life Situation 1 Year Prior Diagnosis Compared to 3 and 5 Years after Diagnosis 
PLoS ONE  2011;6(3):e18040.
Background
Improved cancer survival poses important questions about future life conditions of the survivor. We examined the possible influence of a breast cancer diagnosis on subsequent working and marital status, sickness absence and income.
Materials
We conducted a matched cohort study including 4,761 women 40–59 years of age and registered with primary breast cancer in a Swedish population-based clinical register during 1993–2003, and 2,3805 women without breast cancer. Information on socioeconomic standing was obtained from a social database 1 year prior and 3 and 5 years following the diagnosis. In Conditional Poisson Regression models, risk ratios (RRs) and 95% confidence intervals (CIs) were estimated to assess the impact of a breast cancer diagnosis.
Findings
Three years after diagnosis, women who had had breast cancer more often had received sickness benefits (RR = 1.49, 95% CI 1.40–1.58) or disability pension (RR = 1.47, 95% CI 1.37–1.58) than had women without breast cancer. We found no effect on income (RR = 0.99), welfare payments (RR = 0.98), or marital status (RR = 1.02). A higher use of sickness benefits and disability pension was evident in all stages of the disease, although the difference in use of sickness benefits decreased after 5 years, whereas the difference in disability pension increased. For woman with early stage breast cancer, the sickness absence was higher following diagnosis among those with low education, who had undergone mastectomy, and had received chemo- or hormonal therapy. Neither tumour size nor presence of lymph nodes metastasis was associated with sickness absence after adjustment for treatment.
Interpretation
Even in early stage breast cancer, a diagnosis negatively influences working capacity both 3 and 5 years after diagnosis, and it seems that the type of treatment received had the largest impact. A greater focus needs to be put on rehabilitation of breast cancer patients, work-place adaptations and research on long-term sequelae of treatment.
doi:10.1371/journal.pone.0018040
PMCID: PMC3068139  PMID: 21479209
13.  Breast cancer associated with primary hyperparathyroidism: a nested case control study 
Clinical Epidemiology  2011;3:103-106.
Background:
Primary hyperparathyroidism (pHPT) is associated with an increased risk of developing breast cancer, but little is known about the underlying factors. The aim of this study was to compare women with a history of pHPT and a reference population in terms of standard factors predictive of prognosis and response to therapy for breast cancer.
Methods:
We analyzed data collected from the National Swedish Cancer Register and from two regional oncologic center registries. Seventy-one women with breast cancer and a history of parathyroid adenomectomy were compared with 338 matched controls with breast cancer only. Tumor size, stage, hormone receptor status, lymph node status, cause of death, and cumulative survival were analyzed.
Results:
The mean age was 69 ± 11 years (95% confidence interval [CI]: 68–70) in both groups and the mean time interval between the parathyroid surgery and breast cancer diagnosis was 91 ± 68 months (95% CI: 72–111). There were no differences between the two groups regarding size, stage, lymph node metastases, or survival, but none of the cases with a history of pHPT were found in Stage III or IV.
Conclusion:
In conclusion, factors predictive of prognosis and response to therapy in women with a history of pHPT and breast cancer are similar to those in breast cancer patients without pHPT.
doi:10.2147/CLEP.S17298
PMCID: PMC3072153  PMID: 21487450
breast cancer; primary hyperparathyroidism; prognostic factors
14.  Risk of thromboembolic diseases in men with prostate cancer: results from the population-based PCBaSe Sweden 
The Lancet Oncology  2010;11(5):450-458.
Summary
Background
Cancer is associated with an increased risk of thromboembolic diseases, but data on the association between prostate cancer and thromboembolic diseases are scarce. We investigated the risk of thromboembolic disease in men with prostate cancer who were receiving endocrine treatment, curative treatment, or surveillance.
Methods
We analysed data from PCBaSe Sweden, a database based on the National Prostate Cancer Register, which covers over 96% of prostate cancer cases in Sweden. Standardised incidence ratios (SIR) of deep-venous thrombosis (DVT), pulmonary embolism, and arterial embolism were calculated by comparing observed and expected (using the total Swedish male population) occurrences of thromboembolic disease, taking into account age, calendar-time, number of thromboembolic diseases, and time since previous thromboembolic disease.
Findings
Between Jan 1, 1997, and Dec 31, 2007, 30 642 men received primary endocrine therapy, 26 432 curative treatment, and 19 526 surveillance. 1881 developed a thromboembolic disease. For men on endocrine therapy, risks for DVT (SIR 2·48, 95% CI 2·25–2·73) and pulmonary embolism (1·95, 1·81–2·15) were increased, although this was not the case for arterial embolism (1·00, 0·82–1·20). Similar patterns were seen for men who received curative treatment (DVT: 1·73, 1·47–2·01; pulmonary embolism: 2·03, 1·79–2·30; arterial embolism: 0·95, 0·69–1·27) and men who were on surveillance (DVT: 1·27, 1·08–1·47; pulmonary embolism: 1·57, 1·38–1·78; arterial embolism: 1·08, 0·87–1·33). Increased risks for thromboembolic disease were maintained when patients were stratified by age and tumour stage.
Interpretation
All men with prostate cancer were at higher risk of thromboembolic diseases, with the highest risk for those on endocrine therapy. Our results indicate that prostate cancer itself, prostate cancer treatments, and selection mechanisms all contribute to increased risk of thromboembolic disease. Thromboembolic disease should be a concern when managing patients with prostate cancer.
Funding
Swedish Research Council, Stockholm Cancer Society, and Cancer Research UK.
doi:10.1016/S1470-2045(10)70038-3
PMCID: PMC2861771  PMID: 20395174
15.  Placental Weight and Risk of Invasive Epithelial Ovarian Cancer with an Early Age of Onset 
Background
Epithelial ovarian cancer is associated with reproductive factors, but we lack knowledge if hormonal factors during pregnancy influence the mother’s risk. Because pregnancy hormones are primarily produced by the placenta, placental weight may be an indirect marker of hormone exposure during pregnancy.
Methods
In a nationwide Swedish cohort study, we included women with singleton births from 1982 to 1989. Women were followed for occurrence of invasive epithelial ovarian cancer, death, or emigration through 2004. Hazard ratios (HR) with 95% confidence intervals (95% CI) from Cox models were used to estimate associations between pregnancy exposures and epithelial ovarian cancer.
Results
Among 395,171 women with information on placental weight in their first recorded birth, 316 women developed invasive epithelial ovarian cancer. Mean age at diagnosis was 44 years. Compared with women with a placental weight of 500 to 699 g, women with a high (≥700 g) placental weight had an increased riskof developing epithelial ovarian cancer (HR, 1.47; 95% CI, 1.14–1.90). Compared with women with term pregnancies (40–41 weeks), women with post-term (≥42 weeks) pregnancies had an increased risk of developing epithelial ovarian cancer (HR, 1.48; 95% CI, 1.00–2.19). These associations were slightly stronger when we included information about women’s overall first birth, and slightly weaker when we included information about last recorded birth or ever last birth from 1982 to 1989.
Conclusions
Because pregnancy hormone levels increase with placental weight, our study supports the hypothesis that hormone exposures during pregnancy influence the risk of invasive epithelial ovarian cancer among young women.
doi:10.1158/1055-9965.EPI-08-0390
PMCID: PMC2643070  PMID: 18768502
16.  Quantification of Normal Cell Fraction and Copy Number Neutral LOH in Clinical Lung Cancer Samples Using SNP Array Data 
PLoS ONE  2009;4(6):e6057.
Background
Technologies based on DNA microarrays have the potential to provide detailed information on genomic aberrations in tumor cells. In practice a major obstacle for quantitative detection of aberrations is the heterogeneity of clinical tumor tissue. Since tumor tissue invariably contains genetically normal stromal cells, this may lead to a failure to detect aberrations in the tumor cells.
Principal Finding
Using SNP array data from 44 non-small cell lung cancer samples we have developed a bioinformatic algorithm that accurately models the fractions of normal and tumor cells in clinical tumor samples. The proportion of normal cells in combination with SNP array data can be used to detect and quantify copy number neutral loss-of-heterozygosity (CNNLOH) in the tumor cells both in crude tumor tissue and in samples enriched for tumor cells by laser capture microdissection.
Conclusion
Genome-wide quantitative analysis of CNNLOH using the CNNLOH Quantifier method can help to identify recurrent aberrations contributing to tumor development in clinical tumor samples. In addition, SNP-array based analysis of CNNLOH may become important for detection of aberrations that can be used for diagnostic and prognostic purposes.
doi:10.1371/journal.pone.0006057
PMCID: PMC2699026  PMID: 19557126
17.  Gestational Age and Fetal Growth in Relation to Maternal Ovarian Cancer Risk in a Swedish Cohort 
Background
Pregnancy influences subsequent maternal ovarian cancer risk. To date, there is limited evidence whether two characteristics of pregnancy, gestational age and birth weight, could modify risk.
Materials and Methods
We studied 1.1 million Swedish women who delivered singleton births between 1973 and 2001. Information on infant gestational age and birth weight was abstracted from the nationwide Swedish Birth Register. Women were followed prospectively through linkage with other population-based registers for occurrence of ovarian cancer, death, or emigration through 2001. Hazard ratios [relative risk (RR), 95% confidence interval (95% CI)] from Cox models were used to estimate associations between gestational age, birth weight, and epithelial ovarian cancer risk.
Results
During 12.6 million person-years, 1,017 epithelial ovarian cancers occurred. Mean age at diagnosis was 43 years. Compared with women with term deliveries (≥40 weeks), women with moderately (35–36 weeks) or very (<35 weeks) preterm deliveries had increased risks of epithelial ovarian cancer (RR 1.4, 95% CI 1.0–2.0 and RR 2.3, 95% CI 1.3–3.8, respectively). In contrast, women giving birth to small-for-gestational-age babies had a reduced risk (RR 0.7, 95% CI 0.4–1.0). Stratifying on birth weight and gestational age, there was a strong protective effect of low birth weight on maternal risk of epithelial ovarian cancer among term deliveries, whereas birth weight seemed to have little effect among preterm births (Pinteraction = 0.022).
Conclusions
Our results lend further support that the hormonal milieu of a pregnancy may modify long-term risk of developing ovarian cancer.
doi:10.1158/1055-9965.EPI-06-0962
PMCID: PMC2646123  PMID: 17855701
18.  Fertility patterns after appendicectomy: historical cohort study 
BMJ : British Medical Journal  1999;318(7189):963-967.
Objective
To examine fertility patterns in women who had their appendix removed in childhood.
Design
Historical cohort study with computerised data and fertility data for this cohort and for an age matched cohort of women from the Swedish general population. The cohorts were followed to 1994.
Setting
General population.
Participants
9840 women who were under 15 years when they underwent appendicectomy between 1964 and 1983; 47 590 control women.
Main outcome measures
Diagnoses at discharge. Distributions of age at birth of first child among women with perforated and non-perforated appendix and women who underwent appendicectomy but were found to have a normal appendix compared with control women by using survival analysis methods. Parity distributions at the latest update of the registry were also examined.
Results
Women with a history of perforated appendix had a similar rate of first birth as the control women (adjusted hazard ratio 0.95; 95% confidence interval 0.88 to 1.04) and had a similar distribution of parity at the end of follow up. Women who had had a normal appendix removed had an increased rate of first births (1.48; 1.42 to 1.54) and on average had their first child at an earlier age and reached a higher parity than control women.
Conclusion
A history of perforated appendix in childhood does not seem to have long term negative consequences on female fertility. This may have important implications for the management of young women with suspected appendicitis as the liberal attitude to surgical explorations with a subsequently high rate of removal of a normal appendix is often justified by a perceived increased risk of infertility after perforation. Women whose appendix was found to be normal at appendicectomy in childhood seem to belong to a subgroup with a higher fertility than the general population.
Key messagesA history of perforated appendix in childhood does not seem to have an adverse effect on female fertilityThe current recommendations of a liberal attitude to exploration in women with suspected appendicitis cannot be justified on the grounds of pervention of infertility
PMCID: PMC27821  PMID: 10195964

Results 1-18 (18)