Marine omega-3 fatty acid intake and survival of stage III colon cancer according to tumor molecular markers in NCCTG Phase III trial N0147 (Alliance)

We examined data from a phase III randomized trial of FOLFOX or FOLFOX + cetuximab among 1,735 stage III colon cancer patients who completed a dietary questionnaire at enrollment. Multivariable hazard ratios and 95% confidence intervals (CIs) were calculated for the association between MO3PUFA and disease-free survival (DFS) and overall survival according to KRAS and BRAFV600E mutations and DNA mismatch repair (MMR) status.

Higher MO3PUFA intake was associated with improved 3-year DFS for KRAS-wildtype tumors (77% vs. 73%; HR, 0.84, 95% CI, 0.67-1.05), but not KRAS-mutant tumors (64% vs. 70%; HR, 1.30, 95% CI, 0.97-1.73; Pinteraction =0.02). Similar heterogeneity was found by MMR (Pinteraction =0.14): higher MO3PUFA was associated with better 3-year DFS for tumors with deficient MMR (72% vs. 67%), but not proficient MMR (72% vs. 72%). No heterogeneity was found by BRAFV600E mutation. Similar findings were obtained for overall survival.

In conclusion, we found a suggestive beneficial association between higher MO3PUFA intake and improved survival among stage III colon cancer patients with wildtype KRAS and deficient MMR. Given the relatively small number of cases with tumor molecular assessments, further studies, preferably through pooled analyses of multiples cohorts, are needed to validate our findings. This article is protected by copyright. All rights reserved.