Dietary fatty acids and prevention of hormone-responsive cancer

The results from some, but not all, epidemiological studies indicate that the level of dietary fat intake and the nature of the constituent fatty acids influence both breast and prostate cancer risk, and disease progression. These observations derive support from the use of animal models, which demonstrate that polyunsaturated omega-6 fatty acids stimulate mammary carcinogenesis and tumor growth and metastasis, whereas long-chain omega-3 fatty acids exhibit inhibitory effects. While studies of prostate cancer are less advanced, the available data are in agreement with those designed to evaluate the associations between breast cancer and dietary fatty acids. In both cases, a multiplicity of biological actions of eicosanoids derived from tumor cell arachidonate metabolism appear to elicit responses, both in the tumor itself and in the host cells that subscribe to its microenvironment. This review concludes that clinical intervention trials designed to reduce total fat intake and increase the ratio of omega-3 to omega-6 fatty acids in the diet should be targeted at groups at a relatively high risk for breast or prostate cancer, and also at postsurgically treated cancer patients with the objective of preventing disease recurrence.