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

Objectives: 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. Methods: 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. Results: 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. Conclusions: 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.