Systematic Review with Meta-Analysis: Low-Level Alcohol Consumption and the Risk of Liver Cancer

BACKGROUND/AIMS: Multiple meta-analyses and observational studies have reported that alcohol is a risk factor for liver cancer. However, whether there is a safe level of alcohol consumption remains unclear. We performed a systematic review and meta-analysis of the correlation between low-level alcohol consumption and the risk of liver cancer. METHODS: Nested case-control studies and cohort studies involving the general population published prior to July 2019 were searched. In total, 28 publications (31 cohorts) with 4,899 incident cases and 10,859 liver cancer-related deaths were included. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: Compared with those with low levels of alcohol consumption, moderate and heavy drinkers (≥1 drink/day for females and ≥2 drinks/day for males) had pooled ORs of 1.418 (95% CI, 1.192 to 1.687; p<0.001) for liver cancer incidence and 1.167 (95% CI, 1.056 to 1.290; p=0.003) for liver cancer mortality. The pooled OR for liver disease-related mortality for those with more than low levels of alcohol consumption was 3.220 (95% CI, 2.116 to 4.898; p<0.001) and that for all-cause mortality was 1.166 (95% CI, 1.065 to 1.278; p=0.001). The sensitivity analysis showed that none of the studies had a strong effect on the pooled OR. The Egger test, Begg rank correlation test, and the funnel plot showed no overt indication of publication bias. CONCLUSIONS: Continuous consumption of more than a low-level of alcohol (≥1 drink/day for females and ≥2 drinks/day for males) is related to a higher risk of liver cancer.