ObjectiveTo evlauate the role of hormone replacement therapy (HRT) as a risk factor for the development of epithelial ovarian cancer.MethodsA case-control study was perfromed that used 491 patients with epithelial ovarian cancer frequency matched for age at diagnosis (±5 years) with a control population of 741 patients with malignancies of nonestrogen-dependent tissues. The odds ratio (OR) for the development of epithelial ovarian cancer was estimated using logistic regression analysis with adjustment ofr age at diagnosis, parity, oral contraceptive use, smoking history, family history of epithelial ovarian cancer, age at menarche, menopausal status, income, and education.ResultsOne hundred of 491 patients (20.4%) in the study population had ever used 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 significant association between HRT and specific histologic subtypes of epithelial ovarian cancer was not demonstrable for serous cystadenocarcinoma (OR 1.2, 95% CI 0.4, 3.4), or endometrioid carcinoma (OR 0.4; 95% CI 0.2, 1.2). A significant association between duration of use of HRT and the risk of developing epithelial ovarian cancer was not demonstrable for under 5 years (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).ConclusionA significant association between the use of HRT and the risk of developing epithelial ovarian cancer, even with prolonged exposure, is not demostrable.