Alcohol Consumption and Cancer Risk: Two Sample Mendelian Randomization

Although numerous observational studies have reported on the association between alcohol consumption and cancer, insufficient studies have estimated the causality. Our study evaluated the causal relationship between various types of cancer according to the frequency of drinking and the amount of alcohol consumed. The research data were obtained from the publicly available MR-Base platform. The frequency and amount of drinking were selected as the exposure, and 16 cancer types were selected as the outcome. Two-sample summary data Mendelian randomization (2SMR) was conducted to examine the causality between alcohol consumption and cancer type. Additionally, for cancers suspected of pleiotropy, outliers were removed and re-analyzed through radial MR. The MR results using the inverse variance weighted (IVW) method were different before and after removing outliers. The biggest differences were found for esophageal cancer and biliary tract cancer. For esophageal cancer, after removing outliers (rs13102973, rs540606, rs650558), the OR (95% CI) was 3.44 (1.19–9.89), which was statistically significant (p = 0.02172). Even in biliary tract cancer, after removing outliers (rs13231886, rs58905411), the OR (95% CI) was 3.86 (0.89–16.859), which was of borderline statistical significance (p = 0.07223). The strongest association was found for esophageal cancer. For other cancers, the evidence was not sufficient to draw conclusions. More research is needed to understand the causality between drinking and cancer.