Abstract P4-09-06: No inverse association between breast cancer risk and n-3 unsaturated fatty acids in erythrocytes among Japanese women

Dietary intake of fish, a major source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has been proposed to reduce the cancer risk. In contrast to the animal studies, their protective effects for breast cancer are equivocal in epidemiological studies. In a case-control study, we examined the association between the ratio of DHA (EPA) to aracidonic acid (AA) in erythrocytes and breast cancer risk in Kagoshima, Japan. All subjects, 147 breast cancer cases and 253 controls, were interviewed and information on lifestyles including smoking and alcohol drinking habits, menstrual and reproductive history, family history of cancer, and physical activity, was collected using a questionnaire. Erythrocyte fatty acids were measured by gas-liquid chromatography. According to the results of questionnaire survey, there was no inverse association between the frequency of fish intake and the risk of breast cancer. In pre-menopausal women, there was no significant association between DHA / AA and breast cancer risk (P for trend = 0.953). For post-menopausal women, although the first quartile of DHA / AA showed the lowest breast cancer risk, the risk was the highest in the second quartile and decreased after that. There was no association between EPA / AA and breast cancer risk in both pre- and post-menopausal women. These results suggested no inverse linear association between DHA(EPA) / AA in erythrocytes and breast cancer risk. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-09-06.