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 relative risks (RRs) with 95% CI using random-effects models.

RESULTS: Twelve studies with 32,846 colorectal cancer patients were included in the meta-analysis. Compared to no alcohol consumption, light (RR=0.87; 95% CI: 0.81-0.94) and moderate (RR=0.92; 95% CI: 0.85-1.00) pre-diagnostic alcohol consumption were associated with lower risk of all-cause mortality. Light pre-diagnostic alcohol consumption was associated with lower risk of colorectal cancer-specific mortality (RR=0.87; 95% CI: 0.78-0.98). However, heavy pre-diagnostic alcohol consumption was not significantly associated with colorectal cancer survival. In a dose-response analysis, a non-linear association between pre-diagnostic alcohol consumption and all-cause mortality was observed (P for non-linearity=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 post-diagnostic alcohol consumption and colorectal cancer survival.

CONCLUSIONS: Light and moderate pre-diagnostic 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.