Endometrial Cancer and Estrogen Use

Abstract

Our case–control study of the relation between estrogen use and endometrial cancer involved 451 cases and 888 controls. The overall risk of endometrial carcinoma was six-fold for estrogen users as compared with nonusers; long-term users (> five years) had a 15-fold risk. Excess risk was present for both diethylstilbestrol and conjugated estrogens. The risk associated with cyclic use was as great as that for continuous use. Increased risk was associated with estrogen use for all histologic grades of the tumor. The risk of advanced-stage carcinoma was fourfold for estrogen users, but the confidence interval was wide, and this question requires further study.