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.