HORMONE REPLACEMENT THERAPY AS A RISK FACTOR FOR EPITHELIAL OVARIAN-CANCER - RESULTS OF A CASE-CONTROL STUDY

Objective: To evaluate the role of hormone replacement therapy (HRT) a s a risk factor for the development of epithelial ovarian cancer. Meth ods: A case-control study was performed that used 491 patients with ep ithelial ovarian cancer frequency matched for age at diagnosis (+/-5 y ears) with a control population of 741 patients with malignancies of n on-estrogen-dependent tissues. The odds ratio (OR) for the development of epithelial ovarian cancer was estimated using logistic regression analysis with adjustment for age at diagnosis, parity, oral contracept ive use, smoking history, family history of epithelial ovarian cancer, age at menarche, menopausal status, income, and education. Results: O ne hundred of 491 patients (20.4%) in the study population had ever us ed HRT, and 160 of 741 patients (21.6%) in the control population had ever used HRT (OR 0.85; 95% confidence interval [CI] 0.62, 1.2). A sig nificant association between HRT and specific histologic subtypes of e pithelial ovarian cancer was not demonstrable for serous cystadenocarc inoma (OR 1.2, 95% CI 0.8, 1.7), clear cell carcinoma (OR 1.1, 95% CI 0.4, 3.4), or endometrioid carcinoma (OR 0.4; 95% CI 0.2, 1.2). A sign ificant association between duration of use of HRT and the risk of dev eloping epithelial ovarian cancer was not demonstrable for under 5 yea rs (OR 0.8; 95% CI 0.5, 1.2), 5-9 years (OR 0.6; 95% CI 0.3, 1.1), or 10 or more years (OR 0.6; 95% CI 0.3, 1.4). Conclusion: A significant association between the use of HRT and the risk of developing epitheli al ovarian cancer, even with prolonged exposure, is not demonstrable. (C) 1997 by The American College of Obstetricians and Gynecologists.