Recent studies have focused on breast, cervical, and endometrial cancers, utilizing dietary interviews, biochemical methods, and anthropometric measurements to assess exposure. Two 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, exercise, weight, endogenous hormones, and lifestyle. In the Asian-American study, grandparents' birthplace and subjects' residential history determine a fivefold difference in incidence. Two case-control studies of cervical cancer have been completed. One in the U.S. shows no reduction in risk of invasive or in situ disease with increased intake of carotenoids, vitamin A, vitamin C, or folate. One in Latin America, however, suggests that elevated levels of vitamin C and carotenoids were associated with reduced risk of disease; no effects were detected for vitamin A or folate. A study of vulvar cancer in the U.S. found that intake of alpha-carotene and yellow-orange vegetables might be protective. Since international comparisons demonstrate that endometrial cancer is correlated with fat consumption, a case-control study is investigating etiologic roles of diet and anthropometry. Data from two national surveys have been used to identify nutrients, food groups, and cooking practices associated with a low-fat diet to suggest alternative hypotheses for epidemiologic evaluation. Finally, a liquid chromatography method with high recovery and resolution of individual blood carotenoids has been developed to evaluate further the reduced risk of lung cancer associated with high blood beta-carotene levels in prospective studies.
