A prospective cohort study of cigarette smoking, alcohol drinking and liver cancer incidence in Chinese men

Population-based prospective studies on the associations of cigarette smoking, alcohol drinking, and primary liver cancer remain limited in Mainland China. Our study was designed to evaluate such relationships in middle-aged Chinese men.Self-reported habits of cigarette smoking and alcohol drinking were obtained from all cohort members at the baseline survey. The outcomes were identified through in-person follow-up and annual record linkage to multiple statistics of vital and cancer registration. Age-adjusted and multivariable-adjusted hazard ratio (HR) and their corresponding 95% confidence interval (CI) were estimated utilizing the Cox regression model.After a median follow-up of 12.31 years, 329 cases of incident primary liver cancer occurred among 45 266 male participants. Compared with never smoker, former smoker was positively associated with liver cancer risk, with a multivariable-adjusted HR of 1.42 (95% CI 1.02-1.98). Individuals who had smoked for more than 40 years had a 49% increased risk of liver cancer (HR≥40 years 1.49, 95% CI 1.04-2.14). The association of alcohol drinking with liver cancer showed no statistical significance.Our study provided evidence that cigarette smoking was positively associated with an increased liver cancer risk among Chinese men. Attention to such non-viral modifiable risk factors to prevent liver cancer effectively is needed.