Epithelial ovarian cancer risk among women with polycystic ovary syndrome.

Objective: To investigate the relationship between polycystic ovary syndrome (PCOS) and ovarian cancer, and to present three hypotheses regarding hormonal factors and the risk of ovarian cancer in women.
Methods: Data were analyzed from a population-based, case-control study, the Cancer and Steroid Hormone Study, to test the hypotheses. Four hundred seventy-six subjects with histologically confirmed epithelial ovarian cancer were identified from eight tumor registries of the Surveillance Epidemiology and End Results program. The study included 4081 controls ascertained via random-digit telephone dialing. All subjects and controls were aged 20-54 years.
Results: Seven subjects with ovarian cancer and 24 controls reported that they had been diagnosed with PCOS before the study period. Ovarian cancer risk was found to increase 2.5-fold (95% confidence interval [CI] 1.1-5.9) among women with PCOS. This association is found to be stronger among women who never used oral contraceptives (odds ratio [OR] 10.5, 95% CI 2.5-44.2) and women who were in the first quartile of body mass index (13.3-18.5 kg/m2) at age 18 (OR 15.6, 95% CI 3.4-71.0).
Conclusion: The data suggest that the hormonal status of women with PCOS featuring abnormal patterns of gonadotropic secretion (enhanced levels of LH) in lean women may be a mitigating factor for the observed association between PCOS and ovarian cancer. We hope that our preliminary data stimulate further investigation of the testable hypotheses.