S555 The Role of Omega Fatty Acids and Colorectal Cancer Risk—A Systematic Review

Introduction: Colorectal cancer (CRC) is the third leading cause of cancer deaths in the United States. There has been literature suggesting that omega polyunsaturated fatty acids (PUFA) might be protective against colorectal cancer by promoting cell death and reducing inflammation via downregulating the inflammatory cascade through inhibition of prostaglandin-endoperoxide synthase 2. Laboratory research shows benefit whereas observational studies in humans show no overall association. Methods: PRISMA guidelines were followed. MeSH terms including (omega fatty acids or omega-polyunsaturated fatty acids) AND (colorectal cancer or colorectal carcinoma) were used. Cochrane, PubMed, and Google Scholar were used as search engines. Nineteen studies resulted, two were duplicates, six were case reports, and four were literature reviews, leaving seven studies for review, which includes randomized control trials and prospective cohort studies. Results: Alliance trial showed patients with high intake of marine Omega-3 PUFAs and dark fish after colon cancer diagnosis may have longer disease-free survival (DFS). Further a subgroup analysis of this trial showed improved 3-year DFS for wild KRAS mutation but P < 0.05 proved it to be insignificant. Non-KAS tumors, however, showed a hazard ratio of 1.3 with a P = 0.02, indicating an inverse correlation. Higher consumption was associated with better 3-year DFS for tumors with deficient MMR (72% vs 67%) but not proficient MMR (72% vs 72%). The other trial utilizing VITAL cohort showed decrease in CRC risk with PUFA supplementation in men but no association in women. The prospective cohort study revealed no association between fish, omega-3 or omega-6 PUFA intake and CRC risk. Results suggest that associations between PUFA intake and CRC may vary by gender, subsite, and genetic risk. Conclusion: Omega fatty acids have variable mechanisms of action to explain pro and anti-apoptotic effects. Based on the available data, there is no significant association between omega fatty acid supplementation and colorectal cancer risk. Further studies are required to look for the incidence of colorectal cancer and its association with omega fatty acid supplementation.