Dietary intake of fish, polyunsaturated fatty acids, and survival after breast cancer: A population‐based follow‐up study on Long Island, New York

BACKGROUND In laboratory experiments, ω‐3 polyunsaturated fatty acids (PUFAs) have been found to reduce inflammatory eicosanoids resulting from ω‐6 PUFA metabolism via competitive inhibition, and the ω‐3‐induced cytotoxic environment increases apoptosis and reduces cell growth in breast cancer cells. To the authors' knowledge, epidemiologic investigations regarding whether dietary ω‐3 PUFA intake benefits survival after breast cancer are limited and inconsistent. METHODS The authors used resources from a population‐based follow‐up study conducted on Long Island, New York, among 1463 women newly diagnosed with first primary breast cancer who were interviewed an average of approximately 3 months after diagnosis to assess risk and prognostic factors, including dietary intake (using a food frequency questionnaire). Vital status was determined through 2011, yielding a median follow‐up of 14.7 years and 485 deaths. Adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards regression. RESULTS All‐cause mortality was reduced among women with breast cancer reporting the highest quartile of intake (compared with never) for tuna (HR, 0.71; 95% CI, 0.55‐0.92), other baked/broiled fish (HR, 0.75; 95% CI, 0.58‐0.97), and the dietary long‐chain ω‐3 PUFAs docosahexaenoic acid (HR, 0.71; 95% CI, 0.55‐0.92) and eicosapentaenoic acid (HR, 0.75; 95% CI, 0.58‐0.97). CONCLUSIONS All‐cause mortality was reduced by 16% to 34% among women with breast cancer who reported a high intake of fish and long‐chain ω‐3 PUFAs. Long‐chain ω‐3 PUFA intake from fish and other dietary sources may provide a potential strategy to improve survival after breast cancer. Cancer 2015;121:2244–2252. © 2015 American Cancer Society. All‐cause mortality was reduced by 16% to 34% among women with breast cancer who reported a high intake of fish and long‐chain ω‐3 polyunsaturated fatty acids. Therefore, pending additional replication, long‐chain ω‐3 polyunsaturated fatty acid intake from fish and other dietary sources may provide a potential strategy for improving survival after a diagnosis of breast cancer.