Association between Alcohol Consumption and Survival in Colorectal Cancer: A Meta-analysis

Background: Although an association between alcohol consumption and risk of colorectal cancer is well established, little is known about the association between alcohol consumption and colorectal cancer survival. We conducted a meta-analysis of prospective cohort studies to quantitatively assess this association. Methods: Data searches were performed using PubMed and ISI Web of Science databases through December 2018. We estimated pooled RRs with 95% confidence intervals (CI) using random-effects models. Results: Twelve studies with 32,846 patients with colorectal cancer were included in the meta-analysis. Compared with no alcohol consumption, light (RR = 0.87; 95% CI, 0.81-0.94) and moderate (RR = 0.92; 95% CI, 0.85-1.00) prediagnostic alcohol consumption were associated with lower risk of allcause mortality. Light prediagnostic alcohol consumption was associated with lower risk of colorectal cancer-specific mortality (RR = 0.87; 95% CI, 0.78-0.98). However, heavy prediagnostic alcohol consumption was not significantly associated with colorectal cancer survival. In a dose-response analysis, a nonlinear association between prediagnostic alcohol consumption and all-cause mortality was observed (P-nonlinearity = 0.0025), showing the reduction in RR at <30 g/day of alcohol consumption. By type of alcohol, wine consumption was associated with lower risk of mortality from all-causes and colorectal cancer, but a positive association was observed between moderate liquor consumption and all-cause mortality. There was no association between postdiagnostic alcohol consumption and colorectal cancer survival. Conclusions: Light and moderate prediagnostic alcohol consumption were associated with better survival in colorectal cancer. Impact: Our findings suggest that light and moderate alcohol consumption may be associated with better survival in colorectal cancer, but further studies are warranted.