A cohort study of nutritional factors and endometrial cancer

To evaluate the role of nutritional factors in the etiology of endometrial cancer, we performed a case-cohort analysis using data from women enrolled in the National Breast Screening Study in Canada from 1980 to 1985. For thi s analysis, a subcohort was constructed by selecting a 10% random sample fr om the 56,837 women in the dietary cohort. Cases were the 221 women diagnos ed with incident adenocarcinoma of the endometrium during follow-up to Dece mber 31, 1993 and ascertained by record linkage to the Canadian Cancer Data base. Information on usual diet at enrolment and other epidemiological vari ables was collected by means of self-administered questionnaires. Hazard ra tios were obtained from proportional hazards regression models, with estima tion of robust standard errors. We found a strong association of endometria l cancer with body mass index > 25 kg/m(2) (hazard ratio 2.72, 95% CI: 2.06 -3.50). Endometrial cancer risk was not associated significantly with intak es of total energy, carbohydrates, proteins, total fat and major fatty acid s, total dietary fiber and various types of fibers, vitamin C, E and A, fol ic acid, beta -carotene, lutein, or cryptoxanthin. Some decrease in risk wa s noted with relatively high intakes of saturated fat, animal fat or lycope ne. The associations observed in the study were independent of total energy intake and most non-dietary risk factors. The study suggests that dietary intakes of energy and most major nutrients are not related to the risk of e ndometrial cancer among Canadian women.