Risk of epithelial ovarian tumors among women with polycystic ovary syndrome: A nationwide population‐based cohort study

Abstract

An association between polycystic ovary syndrome (PCOS) and epithelial ovarian tumors is biologically plausible as conditions inherent to PCOS such as excessive androgenic hormones, reproductive factors and obesity are also risk factors for these hormone-sensitive tumors. However, previous studies have showed conflicting results and have various methodological limitations. This population-based cohort study investigates the association between PCOS and epithelial ovarian tumors and includes all women born in Denmark between January 1, 1940 and December 31, 1993 (n = 1 719 304). PCOS diagnoses, ovarian cancer and borderline ovarian tumor diagnoses, covariates, migration and vital status were obtained from the Danish national registers. Adjusted cox proportional hazard regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CI) for epithelial ovarian cancer and for borderline ovarian tumors overall as well as for histological subtypes separately. During median 26 years of follow-up we identified 6490 women with ovarian cancer and 2990 women with borderline ovarian tumors. Overall, we observed no marked associations between a diagnosis of PCOS and overall epithelial ovarian cancer or overall epithelial borderline ovarian tumors, irrespective of time since diagnosis. However, we found an increased risk of ovarian cancer among postmenopausal women with PCOS (HR 2.28 95% CI 1.02-5.09) and an increased risk of serous borderline ovarian tumors (HR 2.34 95% CI 1.21-4.53) in women with PCOS compared with women without PCOS. Importantly, low statistical precision is a crucial limitation of our study and in previous studies and larger studies with longer follow-up are therefore warranted.

Large-scale genome-wide association study of 398,238 women unveils seven novel loci associated with high-grade serous epithelial ovarian cancer risk

“…A linkage study identified FST as a candidate gene for polycystic ovary syndrome (PCOS) 78 . PCOS may be associated with an increased risk of borderline or postmenopausal ovarian cancer 79 , although a recent Mendelian Randomization study found that genetically predicted PCOS was associated with decreased risk of ovarian cancer 80 . A GWAS of African ancestry women found rs37792 near FST to be genome-wide statistically significantly associated with HGSOC in African ancestry women 81 .…”