Recent studies on diet and nutrition in cancer etiology within the EEB have focused on breast, cervical, endometrial, and colorectal cancers, utilizing both dietary interview and biochemical methods to assess exposure. Two large case-control studies of breast cancer, one in Asian-Americans and the other in U.S. whites and blacks, are evaluating the role of diet, alcohol, physical exercise, weight patterns, lifestyle patterns, and endogenous hormones. In an analysis of data from a breast screening program, height was consistently associated with an increased risk of breast cancer, but relative weight was associated with risk only in older postmenopausal women. Since endometrial cancer incidence is highly correlated with national fat consumption, a case-control study is investigating the role of diet and obesity in its etiology. Two case-control studies of cervical cancer, one in the U.S. and the other in four Latin American countries, have been completed. The U.S. study shows no reduction in risk of invasive or in situ disease with increased intake of carotenoids, vitamin A, vitamin C, or folacin, although serum values remain to be evaluated. The Latin American study suggests that beta-carotene and vitamin C are associated with reduced risk. A parallel study of vulvar cancer was among the first to evaluate individual carotenoids and found evidence that alpha-carotene and dark yellow-orange vegetables might be protective. Research on colorectal cancer is focusing on the fecal mutagens, probably heterocyclic amines, produced by well-cooked meat. Finally, data from the first Health and Nutrition Examination Survey follow-up suggest that vitamin A is significantly associated with increased risk of prostate cancer and that the metabolic consequences of disease are not responsible.
