Post diagnosis diet quality and colorectal cancer survival

Diet quality has shown to influence colorectal cancer (CRC) risk, however, its association with CRC survival is unknown. Therefore, we prospectively assessed the association between dietary quality scores, dietary patterns and survival among 1628 women and 532 men diagnosed with stages 1 to 3 CRC. Post diagnosis diet information was collected via a food frequency questionnaire administered at least 6 months after diagnosis to avoid diet change due to active treatment. We computed scores for the Alternate Healthy Eating Index (AHEI) 2010, alternate Mediterranean Diet score (aMED) and Dietary Approaches to Stop Hypertension score (DASH) and derived two dietary patterns, Western and Prudent, by principal component analysis for each individual. In up to 14 years of follow‐up, we documented 485 deaths in women and 256 in men. After adjusting for potential confounders, women with higher AHEI2010 or aMED scores had a significantly better overall survival (RR comparing extreme quintiles of AHEI‐2010 = 0.66, 95% CI 0.49 – 0.91, p trend = 0.001; aMED = 0.79, 95% CI 0.58 – 1.07, p trend = 0.03). However, these scores had no association with CRC survival. In men, there was no clear association between diet quality scores and survival. Prudent or Western pattern were not associated with survival in women or men. In conclusion, a higher AHEI2010 or aMed score may be associated with better overall survival after CRC diagnosis in women.