Association of Daily Alcohol Consumption and Drinking Patterns with Risk of Primary Malignant Brain Tumor in Korean Adults: A Retrospective Cohort Study

Evidence on whether alcohol consumption and drinking patterns contribute to the risk of primary malignant brain tumors remains limited.We examined associations of daily alcohol consumption, drinking frequency, and heavy episodic drinking with tumor incidence in a nationwide cohort.We analyzed data from the National Health Insurance Service-National Sample Cohort (version 2.2), including 240,948 adults aged ≥ 20 years who completed a general health screening between 2006 and 2008.Alcohol-related behaviors were assessed using standardized questionnaires.Incident primary malignant brain tumors were identified using code C71 and the special registration code V193.Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards models adjusting for sociodemographic and lifestyle factors.Over a mean follow-up of 12 years, 209 incident malignant brain tumors occurred (7.2 per 100,000 person-years).Daily alcohol consumption and heavy episodic drinking were not associated with tumor risk.In contrast, drinking frequency showed a positive association: participants who drank almost daily had a higher risk (vs.non-drinkers) (HR, 2.61; 95% CI, 1.21-5.61;P-trend = 0.0347).Sensitivity analyses restricted to adults aged ≥ 40 years and excluding early cases (3-or 5-year latency) yielded similar results.No effect modification was observed.In this nationwide Korean cohort, near-daily drinking, rather than daily alcohol consumption or amount consumed per occasion, was associated with an elevated risk of primary malignant brain tumors.These findings suggest that drinking frequency may represent an independent dimension of alcohol exposure relevant to brain tumor risk.