Erythrocyte membrane phospholipid fatty acid concentrations and risk of colorectal adenomas: a case-control nested in the French E3N-EPIC cohort study.

BACKGROUND Although dietary fatty acids may influence colorectal carcinogenesis, few studies have examined the association with adenoma risk. We assessed the association between biomarkers of dietary fatty acids or metabolism of fatty acids and the risk of colorectal adenomas in a nested case-control study from the French E3N-EPIC cohort. METHODS Among 13,106 women without prevalent cancer who completed the diet history questionnaire and who provided blood samples, 328 cases of adenomatous polyp were identified during an average of 6.6-year follow-up and randomly matched to 619 polyp-free colonoscopy controls. Erythrocyte membrane phospholipid fatty acid concentrations were determined by gas chromatography. Adjusted ORs for risk of colorectal adenomas with increasing concentrations of fatty acids were calculated using conditional logistic regression, separately for advanced and nonadvanced adenomas. RESULTS Associations were stronger with advanced than nonadvanced adenomas. High concentration of pentadecanoate plus heptadecanoate acids were inversely associated with the risk of advanced adenomas [highest vs. lowest tertile: OR(T3vsT1) = 0.40 (95% confidence interval (CI) 0.20-0.79); P(trend) = 0.009]. Oleic acid was associated with an increased risk of advanced adenomas [OR(T3vsT1) = 2.32 (1.16-4.64); P(trend) = 0.018]. Some polyunsaturated fatty acids were associated with the risk of advanced adenomas, either positively for di-homo-γ-linolenate [OR(T3vsT1) = 2.07 (1.15-3.72); P(trend) = 0.013], or negatively for eicosapentaenoic and docosahexaenoic acids [OR(T3vsT1) = 0.50 (0.27-0.93); P(trend) = 0.044 and OR(T3vsT1) = 0.50 (0.26-0.96); P(trend) = 0.028, respectively]. CONCLUSION A specific erythrocyte membrane phospholipid fatty acid profile, presumably reflecting both a complex dietary pattern and altered fatty acid metabolism, is associated with advanced colorectal adenoma risk. IMPACT Adenomas could be a target for primary prevention of colorectal cancer, using interventional strategy based on lipidomic profile of patients.