Association of dietary vitamin A, carotenoids, and other antioxidants with the risk of ovarian cancer

Antioxidants may protect the ovaries from oxidative damage and reduce the risk of ovarian cancer. Although a few studies have examined the relation of antioxidant intake to the risk of ovarian cancer, the results have been inconclusive. Questions still remain regarding the effects of confounding factors, such as menopause, tobacco smoking, and alcohol drinking, on the association between antioxidants and ovarian cancer development. Objective: To examine the association of the consumption of micronutrients from foods and supplements with the risk of ovarian cancer. Methods: A structured questionnaire was administered to 558 histologically confirmed epithelial ovarian cancer cases and 607 population controls from a multiethnic, population-based case-control study conducted between 1993 and 1999 in Hawaii and Los Angeles. Results: Overall, vitamin A and carotene intakes were modestly associated with a reduced risk of ovarian cancer. Inverse gradients in ovarian cancer risk with increasing dietary intake of vitamin A and beta-carotene were somewhat stronger among women with mucinous histologic types, smokers, and nondrinkers. A significant positive trend in risk associated with increasing beta-cryptoxanthin intake was observed among postmenopausal women, among women with nonmucinous tumors, and among nonsmokers. The intake of other carotenoids and antioxidants, either from foods or supplements, was unrelated to ovarian cancer risk. Conclusion: Our findings suggest that dietary vitamin A and beta-carotene are modestly protective against ovarian cancer, particularly among smokers. Our data suggest a role for retinoic acid signaling pathways in ovarian carcinogenesis.