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.
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.
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.
Light and moderate pre-diagnostic alcohol consumption were associated with better survival in colorectal cancer.
Our findings suggest that light and moderate alcohol consumption may be associated with better survival in colorectal cancer, but further studies are warranted.