Marine ω-3 Polyunsaturated Fatty Acid and Fish Intake after Colon Cancer Diagnosis and Survival: CALGB 89803 (Alliance).

Author(s): Van Blarigan EL,  Fuchs CS,  Niedzwiecki D,  Ye X,  Zhang S,  Song M,  Saltz LB,  Mayer RJ,  Mowat RB,  Whittom R,  Hantel A,  Benson A,  Atienza D,  Messino M,  Kindler H,  Venook A,  Ogino S,  Giovannucci EL,  Meyerhardt JA

Journal: Cancer Epidemiol Biomarkers Prev

Date: 2018 Apr

Major Program(s) or Research Group(s): NCORP

PubMed ID: 29358223

PMC ID: PMC5939380

Abstract: Background: Marine ω-3 polyunsaturated fatty acids (PUFAs), primarily found in dark fish, may prevent colorectal cancer progression, in part through inhibition of prostaglandin-endoperoxide synthase 2 (PTGS2). However, data in humans are limited.Methods: We examined marine ω-3 PUFAs and fish intake and survival among 1,011 colon cancer patients enrolled in Cancer and Leukemia Group B 89803 between 1999 and 2001 and followed through 2009. Diet was assessed during and 6 months after chemotherapy. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free (DFS), recurrence-free (RFS), and overall survival (OS).Results: We observed 343 recurrences and 305 deaths (median follow-up: 7 years). Patients in the highest vs. lowest quartile of marine ω-3 PUFA intake had an HR for DFS of 0.72 (95% CI, 0.54-0.97; Ptrend = 0.03). Individuals who consumed dark fish ≥1/week versus never had longer DFS (HR 0.65; 95% CI, 0.48-0.87; P-value = 0.007), RFS (HR 0.61; 95% CI, 0.46-0.86; Ptrend = 0.007), and OS (HR 0.68; 95% CI, 0.48-0.96; Ptrend = 0.04). In a subset of 510 patients, the association between marine ω-3 PUFA intake and DFS appeared stronger in patients with high PTGS2 expression (HR 0.32; 95% CI, 0.11-0.95; Ptrend = 0.01) compared with patients with absent/low PTGS2 expression (HR 0.78; 95% CI, 0.48-1.27; Ptrend = 0.35; Pinteraction = 0.19).Conclusions: Patients with high intake of marine ω-3 PUFAs and dark fish after colon cancer diagnosis may have longer DFS.Impact: Randomized controlled trials examining dark fish and/or marine ω-3 PUFA supplements and colon cancer recurrence/survival are needed. Cancer Epidemiol Biomarkers Prev; 27(4); 438-45. ©2018 AACR.