Light, moderate drinking beneficial for colorectal cancer survival

Light to moderate alcohol consumption confers survival gains in colorectal cancer patients, according to the results of a meta-analysis.

Researchers searched multiple online databases for prospective studies evaluating the effect of alcohol consumption on outcomes including all-cause mortality or colorectal cancer-specific mortality. They used the Newcastle-Ottawa quality assessment scale to estimate the quality of the studies.

The meta-analysis included 12 studies involving a total of 32,846 patients with colorectal cancer. Nine studies looked at prediagnostic alcohol consumption, two studies at postdiagnostic alcohol consumption, and the last one examined both. Eight studies reported data on total alcohol consumption, one study explored types of alcohol (wine, beer and liquor), and three studies reported data on both total alcohol and type of alcohol consumption. All studies were of high or good quality.

Pooled data showed an association between risk of all-cause death and amount of alcohol consumption. Compared with nonconsumption, both light and moderate consumption levels prior to cancer diagnosis were associated with a risk reduction (relative risk [RR], 0.87, 95 percent confidence interval [CI], 0.81–0.94 and RR, 0.92, 95 percent CI, 0.85–1.00, respectively).

Light prediagnostic alcohol consumption was also associated with a risk reduction in terms of colorectal cancer-specific mortality outcome (RR, 0.87, 95 percent CI, 0.78–0.98). There was no significant association found between heavy prediagnostic alcohol consumption and colorectal cancer survival.

Dose–response analysis revealed a nonlinear association between prediagnostic alcohol consumption and all-cause mortality (p-nonlinearity=0.0025), with the protective effect evident at <30 g/day of alcohol consumption. With regard to type of alcohol, wine was associated with reduced risk of mortality from all causes and colorectal cancer, whereas moderate liquor consumption positively correlated with all-cause mortality.

Postdiagnostic alcohol consumption was not associated with colorectal cancer survival.

Although more large and well-designed prospective studies are needed, the findings indicate that light and moderate alcohol consumption are unlikely to have a critical harmful effect on survival in patients with colorectal cancer, the researchers said.