Phytoestrogen Intake and Endometrial Cancer Risk

Background: The development of endometrial cancer is largely related to prolonged exposure to unopposed estro-gens. Phytoestrogens (i.e., weak estrogens found in plant foods) may have antiestrogenic effects. We evaluated the associations between dietary intake of seven specific com-pounds representing three classes of phytoestrogens (isofla-vones, coumestans, and lignans) and the risk of endometrial cancer. Methods: In a case–control study from the greater San Francisco Bay Area, we collected dietary information from 500 African American, Latina, and white women aged 35–79 years who were diagnosed with endometrial cancer be-tween 1996 and 1999 and from 470 age- and ethnicity-matched control women identified through random-digit dialing. Un-conditional logistic regression analyses were used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs).