Recruiting and retaining nulliparous individuals with a family history of hypertensive disorders of pregnancy to participate in scientific research prior to pregnancy: The Sisterhood Study.

Introduction: Recruiting women with a family history (FH) of hypertensive disorders of pregnancy (HDP) to participate in research before pregnancy could offer insight into genetic and lifestyle factors that incur higher risk of cardiovascular disease during pregnancy and throughout the life course. Methods: The Sisterhood Study piloted low-touch, remote recruitment strategies that relied on women with a history of preeclampsia to share study information with family and friends. It aimed to enroll 150 women with a FH of HDP and 150 controls. Results: The study recruited 328 women (104 with a FH of HDP, 131 without a FH, and 93 with unknown FH) prior to pregnancy. The majority identified as non-Hispanic White (74.7%) and had > high school education (91.8%). Discussion: Although the population was enriched with nulliparous women with a FH of HDP, it was not sufficient to recruit a diverse cohort large enough to meet the study aim.

Expanding Our Understanding of Ovarian Cancer Risk: The Role of Incomplete Pregnancies.

BACKGROUND: Parity is associated with decreased risk of invasive ovarian cancer; however, the relationship between incomplete pregnancies and invasive ovarian cancer risk is unclear. This relationship was examined using 15 case-control studies from the Ovarian Cancer Association Consortium (OCAC). Histotype-specific associations, which have not been examined previously with large sample sizes, were also evaluated. METHODS: A pooled analysis of 10 470 invasive epithelial ovarian cancer cases and 16 942 controls was conducted. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between incomplete pregnancies and invasive epithelial ovarian cancer were estimated using logistic regression. All models were conditioned on OCAC study, race and ethnicity, age, and education level and adjusted for number of complete pregnancies, oral contraceptive use, and history of breastfeeding. The same approach was used for histotype-specific analyses. RESULTS: Ever having an incomplete pregnancy was associated with a 16% reduction in ovarian cancer risk (OR = 0.84, 95% CI = 0.79 to 0.89). There was a trend of decreasing risk with increasing number of incomplete pregnancies (2-sided Ptrend < .001). An inverse association was observed for all major histotypes; it was strongest for clear cell ovarian cancer. CONCLUSIONS: Incomplete pregnancies are associated with a reduced risk of invasive epithelial ovarian cancer. Pregnancy, including incomplete pregnancy, was associated with a greater reduction in risk of clear cell ovarian cancer, but the result was broadly consistent across histotypes. Future work should focus on understanding the mechanisms underlying this reduced risk.

Population-based targeted sequencing of 54 candidate genes identifies PALB2 as a susceptibility gene for high-grade serous ovarian cancer.

PURPOSE: The known epithelial ovarian cancer (EOC) susceptibility genes account for less than 50% of the heritable risk of ovarian cancer suggesting that other susceptibility genes exist. The aim of this study was to evaluate the contribution to ovarian cancer susceptibility of rare deleterious germline variants in a set of candidate genes. METHODS: We sequenced the coding region of 54 candidate genes in 6385 invasive EOC cases and 6115 controls of broad European ancestry. Genes with an increased frequency of putative deleterious variants in cases versus controls were further examined in an independent set of 14 135 EOC cases and 28 655 controls from the Ovarian Cancer Association Consortium and the UK Biobank. For each gene, we estimated the EOC risks and evaluated associations between germline variant status and clinical characteristics. RESULTS: The ORs associated for high-grade serous ovarian cancer were 3.01 for PALB2 (95% CI 1.59 to 5.68; p=0.00068), 1.99 for POLK (95% CI 1.15 to 3.43; p=0.014) and 4.07 for SLX4 (95% CI 1.34 to 12.4; p=0.013). Deleterious mutations in FBXO10 were associated with a reduced risk of disease (OR 0.27, 95% CI 0.07 to 1.00, p=0.049). However, based on the Bayes false discovery probability, only the association for PALB2 in high-grade serous ovarian cancer is likely to represent a true positive. CONCLUSIONS: We have found strong evidence that carriers of PALB2 deleterious mutations are at increased risk of high-grade serous ovarian cancer. Whether the magnitude of risk is sufficiently high to warrant the inclusion of PALB2 in cancer gene panels for ovarian cancer risk testing is unclear; much larger sample sizes will be needed to provide sufficiently precise estimates for clinical counselling.

Menopausal hormone therapy prior to the diagnosis of ovarian cancer is associated with improved survival.

PURPOSE: Prior studies of menopausal hormone therapy (MHT) and ovarian cancer survival have been limited by lack of hormone regimen detail and insufficient sample sizes. To address these limitations, a comprehensive analysis of 6419 post-menopausal women with pathologically confirmed ovarian carcinoma was conducted to examine the association between MHT use prior to diagnosis and survival. METHODS: Data from 15 studies in the Ovarian Cancer Association Consortium were included. MHT use was examined by type (estrogen-only (ET) or estrogen+progestin (EPT)), duration, and recency of use relative to diagnosis. Cox proportional hazards models were used to estimate the association between hormone therapy use and survival. Logistic regression and mediation analysis was used to explore the relationship between MHT use and residual disease following debulking surgery. RESULTS: Use of ET or EPT for at least five years prior to diagnosis was associated with better ovarian cancer survival (hazard ratio, 0.80; 95% CI, 0.74 to 0.87). Among women with advanced stage, high-grade serous carcinoma, those who used MHT were less likely to have any macroscopic residual disease at the time of primary debulking surgery (p for trend <0.01 for duration of MHT use). Residual disease mediated some (17%) of the relationship between MHT and survival. CONCLUSIONS: Pre-diagnosis MHT use for 5+ years was a favorable prognostic factor for women with ovarian cancer. This large study is consistent with prior smaller studies, and further work is needed to understand the underlying mechanism.

Association Between Breastfeeding and Ovarian Cancer Risk.

Importance: Breastfeeding has been associated with a reduced risk of epithelial ovarian cancer in multiple studies, but others showed no association. Whether risk reduction extends beyond that provided by pregnancy alone or differs by histotype is unclear. Furthermore, the observed associations between duration and timing of breastfeeding with ovarian cancer risk have been inconsistent. Objective: To determine the association between breastfeeding (ie, ever/never, duration, timing) and ovarian cancer risk overall and by histotype. Design, Setting, and Participants: A pooled analysis of parous women with ovarian cancer and controls from 13 case-control studies participating in the Ovarian Cancer Association Consortium was performed. Odds ratios (ORs) and 95% CIs of the overall association were calculated using multivariable logistic regression and polytomous logistic regression for histotype-specific associations. All data were collected from individual sites from November 1989 to December 2009, and analysis took place from September 2017 to July 2019. Exposures: Data on breastfeeding history, including duration per child breastfed, age at first and last breastfeeding, and years since last breastfeeding were collected by questionnaire or interview and was harmonized across studies. Main Outcomes and Measures: Diagnosis of epithelial ovarian cancer. Results: A total of 9973 women with ovarian cancer (mean [SD] age, 57.4 [11.1] years) and 13 843 controls (mean [SD] age, 56.4 [11.7] years) were included. Breastfeeding was associated with a 24% lower risk of invasive ovarian cancer (odds ratio [OR], 0.76; 95% CI, 0.71-0.80). Independent of parity, ever having breastfed was associated with reduction in risk of all invasive ovarian cancers, particularly high-grade serous and endometrioid cancers. For a single breastfeeding episode, mean breastfeeding duration of 1 to 3 months was associated with 18% lower risk (OR, 0.82; 95% CI, 0.76-0.88), and breastfeeding for 12 or more months was associated with a 34% lower risk (OR, 0.66; 95% CI, 0.58-0.75). More recent breastfeeding was associated with a reduction in risk (OR, 0.56; 95% CI, 0.47-0.66 for <10 years) that persisted for decades (OR, 0.83; 95% CI, 0.77-0.90 for ≥30 years; P for trend = .02). Conclusions and Relevance: Breastfeeding is associated with a significant decrease in risk of ovarian cancer overall and for the high-grade serous subtype, the most lethal type of ovarian cancer. The findings suggest that breastfeeding is a potentially modifiable factor that may lower risk of ovarian cancer independent of pregnancy alone.

Presence and Concentrations of Select Bacterial Vaginosis-Associated Bacteria Are Associated With Increased Risk of Pelvic Inflammatory Disease.

In a vaginal 16S ribosomal RNA gene quantitative PCR study of 17 pelvic inflammatory disease (PID) cases and 17 controls who tested positive for Chlamydia trachomatis, women who additionally tested positive for Atopobium vaginae, Sneathia spp., Megasphaera spp., Eggerthella-like bacterium or Prevotella amnii were more likely to develop PID.

Perspectives on the Future of Epidemiology: A Framework for Training.

Over the past century, the field of epidemiology has evolved and adapted to changing public health needs. Challenges include newly emerging public health concerns across broad and diverse content areas, new methods, and vast data sources. We recognize the need to engage and educate the next generation of epidemiologists and prepare them to tackle these issues of the 21st century. In this commentary, we suggest a skeleton framework upon which departments of epidemiology should build their curriculum. We propose domains that include applied epidemiology, biological and social determinants of health, communication, creativity and ability to collaborate and lead, statistical methods, and study design. We believe all students should gain skills across these domains to tackle the challenges posed to us. The aim is to train smart thinkers, not technicians, to embrace challenges and move the expanding field of epidemiology forward.

Estrogen Plus Progestin Hormone Therapy and Ovarian Cancer: A Complicated Relationship Explored.

BACKGROUND: Menopausal estrogen-alone therapy is a risk factor for endometrial and ovarian cancers. When a progestin is included with the estrogen daily (continuous estrogen-progestin combined therapy), there is no increased risk of endometrial cancer. However, the effect of continuous estrogen-progestin combined therapy on risk of ovarian cancer is less clear. METHODS: We pooled primary data from five population-based case-control studies in the Ovarian Cancer Association Consortium, including 1509 postmenopausal ovarian cancer cases and 2295 postmenopausal controls. Information on previous menopausal hormonal therapy use, as well as ovarian cancer risk factors, was collected using in-person interviews. Logistic regression was used to assess the association between use of continuous estrogen-progestin combined therapy and risk of ovarian cancer by duration and recency of use and disease histotype. RESULTS: Ever postmenopausal use of continuous estrogen-progestin combined therapy was not associated with increased risk of ovarian cancer overall (OR = 0.85, 95% CI = 0.72, 1.0). A decreased risk was observed for mucinous ovarian cancer (OR = 0.40, 95% CI = 0.18, 0.91). The other main ovarian cancer histotypes did not show an association (endometrioid: OR = 0.86, 95% CI = 0.57, 1.3, clear cell: OR = 0.68, 95% CI = 0.40, 1.2; serous: OR = 0.98, 95% CI = 0.80, 1.2). CONCLUSIONS: Given that estrogen-alone therapy has been shown to be associated with increased risk of ovarian cancer, these findings are consistent with the hypothesis that adding a progestin each day ameliorates the carcinogenic effects of estrogen on the cells of origin for all histotypes of ovarian cancer.

Identification of novel epithelial ovarian cancer loci in women of African ancestry.

Women of African ancestry have lower incidence of epithelial ovarian cancer (EOC) yet worse survival compared to women of European ancestry. We conducted a genome-wide association study in African ancestry women with 755 EOC cases, including 537 high-grade serous ovarian carcinomas (HGSOC) and 1,235 controls. We identified four novel loci with suggestive evidence of association with EOC (p < 1 × 10-6 ), including rs4525119 (intronic to AKR1C3), rs7643459 (intronic to LOC101927394), rs4286604 (12 kb 3' of UGT2A2) and rs142091544 (5 kb 5' of WWC1). For HGSOC, we identified six loci with suggestive evidence of association including rs37792 (132 kb 5' of follistatin [FST]), rs57403204 (81 kb 3' of MAGEC1), rs79079890 (LOC105376360 intronic), rs66459581 (5 kb 5' of PRPSAP1), rs116046250 (GABRG3 intronic) and rs192876988 (32 kb 3' of GK2). Among the identified variants, two are near genes known to regulate hormones and diseases of the ovary (AKR1C3 and FST), and two are linked to cancer (AKR1C3 and MAGEC1). In follow-up studies of the 10 identified variants, the GK2 region SNP, rs192876988, showed an inverse association with EOC in European ancestry women (p = 0.002), increased risk of ER positive breast cancer in African ancestry women (p = 0.027) and decreased expression of GK2 in HGSOC tissue from African ancestry women (p = 0.004). A European ancestry-derived polygenic risk score showed positive associations with EOC and HGSOC in women of African ancestry suggesting shared genetic architecture. Our investigation presents evidence of variants for EOC shared among European and African ancestry women and identifies novel EOC risk loci in women of African ancestry.

Novel bacterial vaginosis-associated organisms mediate the relationship between vaginal douching and pelvic inflammatory disease.

OBJECTIVES: We sought to determine whether the relationship between a history of vaginal douching and pelvic inflammatory disease (PID) is mediated by endometrial infection with one or more novel bacterial vaginosis (BV)-associated organisms among Atopobium vaginae, the BV-associated bacterium 1 (BVAB1), neathia (Leptotrichia) amnionii and Sneathia sanguinegens. METHODS: We first conducted log-binomial regression analyses to identify risk factors for endometrial infection in 535 adolescent and adult women with clinically suspected PID in the PID Evaluation and Clinical Health (PEACH) study. We then examined whether endometrial infection by the BV-associated organisms mediated the association between a history of vaginal douching and histologically confirmed PID using inverse probability weighted marginal structural models. RESULTS: Vaginal douching was significantly associated with endometrial infection with one or more of the targeted BV-associated organisms (relative risk (RR) 1.21, 95% CI: 1.08 to 1.35). The total effect estimate suggested that vaginal douching increased the risk of endometritis by 24% (RR 1.24, 95% CI: 1.03 to 1.49). The controlled direct effect of this association was attenuated with endometrial infection by one or more BV-associated organisms (adjusted RR (aRR) 1.00, 95% CI: 0.57 to 1.74) and endometrial infection by all four BV-associated organisms (aRR 0.95, 95% CI: 0.53 to 1.70) as intermediate variables. CONCLUSIONS: Endometrial infection with one or more of the novel BV-associated organisms partially mediated the relationship between vaginal douching and histologically confirmed endometritis in the PEACH study. Frequent vaginal douching may confer risk for endometritis through increasing the risk of endometrial infection by novel-BV-associated organisms. Other potential pathways should be explored.

Gender of offspring and risk of ovarian cancer: The HOPE study.

OBJECTIVE: To examine the association between gender of offspring and epithelial ovarian cancer (EOC). METHODS: We compared gender of offspring between 664 incident EOC cases and 1531 controls participating in a population-based study conducted in Pennsylvania, Ohio, and New York from 2003-2008. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs) adjusting for potential confounders. RESULTS: Bearing a male offspring was associated with an 8 % lower EOC risk; bearing all boys was associated with an 11 % lower risk. Compared to bearing all girls, bearing all boys was associated with a 14 % decrease risk. Increasing number of male offspring increased the protective effect (adjusted-OR: 0.92, 0.91, 0.84, for 1, 2, and 3+ boys compared to all girls). Results where similar when limiting cases to invasive disease and to the high-grade serous histotype. CONCLUSION: Fetal sex, which influences maternal hormonal milieu, may impact EOC risk.

Trichomonas vaginalis, endometritis and sequelae among women with clinically suspected pelvic inflammatory disease.

OBJECTIVE: To ascertain the prevalence of Trichomonas vaginalis and investigate associations between trichomoniasis, endometritis and sequelae among women with pelvic inflammatory disease (PID). METHODS: We assessed the prevalence of trichomoniasis identified via wet mount and its association with histologically confirmed endometritis, infertility and recurrent PID among 647 women in the PID Evaluation and Clinical Health (PEACH) study. Participants were treated for clinically suspected PID and followed for a mean of 84 months for incident sequelae. Analyses were adjusted for age, race, Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and bacterial vaginosis. Additional adjustments were incorporated for history of infertility (models of pregnancy and infertility), history of PID (recurrent PID), and self-reported partner treatment and intercourse between baseline and 30-day follow-up (persistent endometritis). RESULTS: T. vaginalis was present in the vagina of 12.8% of women. The odds of having endometritis at baseline were twice as high among women with trichomoniasis as compared with those without (adjusted OR (AOR): 1.9, 95% CI 1.0 to 3.3). Persistent endometritis was highly prevalent at 30 days (52.1%) and more common among women with baseline trichomoniasis (AOR: 2.6, 95% CI 0.7 to 10.1), although non-significantly. Infertility and recurrent PID were more common among women with trichomoniasis, while rates of pregnancy and live birth were lower. CONCLUSIONS: T. vaginalis was frequently isolated from the vagina of women with PID in the PEACH cohort. Wet mount microscopy for the identification of motile trichomonads was standard practice at the time of the PEACH study, but likely resulted in an underestimation of true T. vaginalis prevalence. Our findings of modest, although non-significant, prospective associations between trichomoniasis and sequelae are novel and underscore the need for additional investigation into whether T. vaginalis may play an aetiological role in adverse reproductive and gynaecological outcomes.

Association between genetically predicted polycystic ovary syndrome and ovarian cancer: a Mendelian randomization study.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a complex endocrine disorder with an estimated prevalence of 4-21% in reproductive aged women. Recently, the Ovarian Cancer Association Consortium (OCAC) reported a decreased risk of invasive ovarian cancer among women with self-reported PCOS. However, given the limitations of self-reported PCOS, the validity of these observed associations remains uncertain. Therefore, we sought to use Mendelian randomization with genetic markers as a proxy for PCOS, to examine the association between PCOS and ovarian cancer. METHODS: Utilizing 14 single nucleotide polymorphisms (SNPs) previously associated with PCOS we assessed the association between genetically predicted PCOS and ovarian cancer risk, overall and by histotype, using summary statistics from a previously conducted genome-wide association study (GWAS) of ovarian cancer among European ancestry women within the OCAC (22 406 with invasive disease, 3103 with borderline disease and 40 941 controls). RESULTS: An inverse association was observed between genetically predicted PCOS and invasive ovarian cancer risk: odds ratio (OR)=0.92 [95% confidence interval (CI)=0.85-0.99; P = 0.03]. When results were examined by histotype, the strongest inverse association was observed between genetically predicted PCOS and endometrioid tumors (OR = 0.77; 95% CI = 0.65-0.92; P = 0.003). Adjustment for individual-level body mass index, oral contraceptive use and parity did not materially change the associations. CONCLUSION: Our study provides evidence for a relationship between PCOS and reduced ovarian cancer risk, overall and among specific histotypes of invasive ovarian cancer. These results lend support to our previous observational study results. Future studies are needed to understand mechanisms underlying this association.

A combination of the immunohistochemical markers CK7 and SATB2 is highly sensitive and specific for distinguishing primary ovarian mucinous tumors from colorectal and appendiceal metastases.

Primary ovarian mucinous tumors can be difficult to distinguish from metastatic gastrointestinal neoplasms by histology alone. The expected immunoprofile of a suspected metastatic lower gastrointestinal tumor is CK7-/CK20+/CDX2+/PAX8-. This study assesses the addition of a novel marker SATB2, to improve the diagnostic algorithm. A test cohort included 155 ovarian mucinous tumors (105 carcinomas and 50 borderline tumors) and 230 primary lower gastrointestinal neoplasms (123 colorectal adenocarcinomas and 107 appendiceal neoplasms). All cases were assessed for SATB2, PAX8 CK7, CK20, and CDX2 expression on tissue microarrays. Expression was scored in a 3-tier system as absent, focal (1-50% of tumor cells) and diffuse ( >50% of tumor cells) and then categorized into either absent/present or nondiffuse/diffuse. SATB2 and PAX8 expression was further evaluated in ovarian tumors from an international cohort of 2876 patients (expansion cohort, including 159 mucinous carcinomas and 46 borderline mucinous tumors). The highest accuracy of an individual marker in distinguishing lower gastrointestinal from ovarian mucinous tumors was CK7 (91.7%, nondiffuse/diffuse cut-off) followed by SATB2 (88.8%, present/absent cut-off). The most effective combination was CK7 and SATB2 with accuracy of 95.3% using the 3-tier interpretation, absent/focal/diffuse. This combination outperformed the standard clinical set of CK7, CK20 and CDX2 (87.5%). Re-evaluation of outlier cases confirmed ovarian origin for all but one case. The accuracy of SATB2 was confirmed in the expansion cohort (91.5%). SATB2 expression was also detected in 15% of ovarian endometrioid carcinoma but less than 5% of other ovarian histotypes. A simple two marker combination of CK7 and SATB2 can distinguish lower gastrointestinal from ovarian primary mucinous tumors with greater than 95% accuracy. PAX8 and CDX2 have value as second-line markers. The utility of CK20 in this setting is low and this warrants replacement of this marker with SATB2 in clinical practice.

Evaluation of vitamin D biosynthesis and pathway target genes reveals UGT2A1/2 and EGFR polymorphisms associated with epithelial ovarian cancer in African American Women.

An association between genetic variants in the vitamin D receptor (VDR) gene and epithelial ovarian cancer (EOC) was previously reported in women of African ancestry (AA). We sought to examine associations between genetic variants in VDR and additional genes from vitamin D biosynthesis and pathway targets (EGFR, UGT1A, UGT2A1/2, UGT2B, CYP3A4/5, CYP2R1, CYP27B1, CYP24A1, CYP11A1, and GC). Genotyping was performed using the custom-designed 533,631 SNP Illumina OncoArray with imputation to the 1,000 Genomes Phase 3 v5 reference set in 755 EOC cases, including 537 high-grade serous (HGSOC), and 1,235 controls. All subjects are of African ancestry (AA). Logistic regression was performed to estimate odds ratios (OR) and 95% confidence intervals (CI). We further evaluated statistical significance of selected SNPs using the Bayesian False Discovery Probability (BFDP). A significant association with EOC was identified in the UGT2A1/2 region for the SNP rs10017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 1.2 × 10-6 , BFDP = 0.02); and an association with HGSOC was identified in the EGFR region for the SNP rs114972508 (per allele OR = 2.3, 95% CI = 1.6-3.4, P = 1.6 × 10-5 , BFDP = 0.29) and in the UGT2A1/2 region again for rs1017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 2.3 × 10-5 , BFDP = 0.23). Genetic variants in the EGFR and UGT2A1/2 may increase susceptibility of EOC in AA women. Future studies to validate these findings are warranted. Alterations in EGFR and UGT2A1/2 could perturb enzyme efficacy, proliferation in ovaries, impact and mark susceptibility to EOC.

Joint exposure to smoking, excessive weight, and physical inactivity and survival of ovarian cancer patients, evidence from the Ovarian Cancer Association Consortium.

PURPOSE: Previous epidemiologic studies have shown that smoking, obesity, and physical inactivity are associated with poor survival following a diagnosis of ovarian cancer. Yet, the combined relationship of these unfavorable lifestyle factors on ovarian cancer survival has not been sufficiently investigated. METHODS: Using data pooled from 13 studies, we examined the associations between combined exposures to smoking, overweight/obesity weight, and physical inactivity and overall survival (OS) as well as progression-free survival (PFS) among women diagnosed with invasive epithelial ovarian carcinoma (n = 7,022). Using age- and stage-adjusted Cox proportional hazards regression models, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with joint exposure to these factors. RESULTS: Combined exposure to current smoking, overweight/obesity, and physical inactivity prior to diagnosis was associated with a significantly increased risk of mortality compared to women who never smoked, had normal body mass index (BMI), and were physically active (HR = 1.37; 95% CI 1.10-1.70). The association for a joint exposure to these factors exceeded that of each exposure individually. In fact, exposure to both current smoking and overweight/obesity, and current smoking and physical inactivity was also associated with increased risk of death (HR = 1.28; 95% CI 1.08-1.52, and HR = 1.26; 95% CI 1.04-1.54, respectively). The associations were of a similar magnitude when former smoking was assessed in combination with the other exposures and when excessive weight was limited to obesity only. No significant associations were observed between joint exposure to any of these factors and PFS. CONCLUSIONS: Joint exposure to smoking, excessive weight, and physical inactivity may negatively impact survival of ovarian cancer patients. These results suggest the importance of examining the combined effect of lifestyle factors on ovarian cancer patients' survival.

Breastfeeding factors and risk of epithelial ovarian cancer.

OBJECTIVE: Previous studies suggest that breastfeeding reduces epithelial ovarian cancer (EOC) risk. However, the effects of age, timing and episode details on the EOC-breastfeeding relationship have not been examined. The objective of this study was to examine the association between breastfeeding factors and epithelial ovarian cancer. METHODS: We examined breastfeeding factors among parous women in a population-based, case-control study conducted in Pennsylvania, Ohio, and New York from 2003 to 2008. We compared 689 incident EOC cases to 1572 community controls. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) associated with breastfeeding patterns adjusting for potential confounders. RESULTS: Compared to never breastfeeding, breastfeeding any offspring was associated with a 30% reduction in EOC risk (OR = 0.70; 95%CI = 0.58-0.85). That association lasted more than 30 years (OR = 0.69, 95%CI = 0.53-0.88). An average breastfeeding episode of 3 months was also associated with reduced risk (OR = 0.73, 95%CI = 0.58-0.80). A greater number of breastfeeding episodes was associated with greater risk reduction (OR = 0.78, 95%CI = 0.64-0.96 and OR = 0.49, 95%CI = 0.36-0.68 1-2 and 3+ episodes, respectively, compared to never breastfed, trend p = 0.01). Longer breastfeeding duration was also associated with reduced risk (OR = 0.75 and 0.62 for less than and greater than 1-year total duration, respectively, compared to never breastfed). An earlier age at first breastfeeding was further associated with increased protection (OR = 0.50-0.80, for first episode at age <25, 25-29, and 30+, respectively, trend p = 0.001). CONCLUSIONS: Breastfeeding for as few as 3 months is associated with reduced EOC risk. Although this association decreases over time, it persists for more than 30 years. Longer cumulative duration, increasing number of breastfeeding episodes, and earlier age at first breastfeeding episode are each associated with increased benefit.

A comprehensive gene-environment interaction analysis in Ovarian Cancer using genome-wide significant common variants.

As a follow-up to genome-wide association analysis of common variants associated with ovarian carcinoma (cancer), our study considers seven well-known ovarian cancer risk factors and their interactions with 28 genome-wide significant common genetic variants. The interaction analyses were based on data from 9971 ovarian cancer cases and 15,566 controls from 17 case-control studies. Likelihood ratio and Wald tests for multiplicative interaction and for relative excess risk due to additive interaction were used. The top multiplicative interaction was noted between oral contraceptive pill (OCP) use (ever vs. never) and rs13255292 (p value = 3.48 × 10-4 ). Among women with the TT genotype for this variant, the odds ratio for OCP use was 0.53 (95% CI = 0.46-0.60) compared to 0.71 (95%CI = 0.66-0.77) for women with the CC genotype. When stratified by duration of OCP use, women with 1-5 years of OCP use exhibited differential protective benefit across genotypes. However, no interaction on either the multiplicative or additive scale was found to be statistically significant after multiple testing correction. The results suggest that OCP use may offer increased benefit for women who are carriers of the T allele in rs13255292. On the other hand, for women carrying the C allele in this variant, longer (5+ years) use of OCP may reduce the impact of carrying the risk allele of this SNP. Replication of this finding is needed. The study presents a comprehensive analytic framework for conducting gene-environment analysis in ovarian cancer.

rs495139 in the TYMS-ENOSF1 Region and Risk of Ovarian Carcinoma of Mucinous Histology.

Thymidylate synthase (TYMS) is a crucial enzyme for DNA synthesis. TYMS expression is regulated by its antisense mRNA, ENOSF1. Disrupted regulation may promote uncontrolled DNA synthesis and tumor growth. We sought to replicate our previously reported association between rs495139 in the TYMS-ENOSF1 3' gene region and increased risk of mucinous ovarian carcinoma (MOC) in an independent sample. Genotypes from 24,351 controls to 15,000 women with invasive OC, including 665 MOC, were available. We estimated per-allele odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression, and meta-analysis when combining these data with our previous report. The association between rs495139 and MOC was not significant in the independent sample (OR = 1.09; 95% CI = 0.97⁻1.22; p = 0.15; N = 665 cases). Meta-analysis suggested a weak association (OR = 1.13; 95% CI = 1.03⁻1.24; p = 0.01; N = 1019 cases). No significant association with risk of other OC histologic types was observed (p = 0.05 for tumor heterogeneity). In expression quantitative trait locus (eQTL) analysis, the rs495139 allele was positively associated with ENOSF1 mRNA expression in normal tissues of the gastrointestinal system, particularly esophageal mucosa (r = 0.51, p = 1.7 × 10-28), and nonsignificantly in five MOC tumors. The association results, along with inconclusive tumor eQTL findings, suggest that a true effect of rs495139 might be small.