Multiple risk factors of hepatocellular carcinoma: A cohort study of 13 737 male adults in Taiwan

In order to explore multiple risk factors of hepatocellular carcinoma (HCC), a total of 13 737 male adult residents in 12 townships were studied for an average follow‐up period of 5.2 years. Sociodemographic characteristics, history of cigarette smoking and alcohol drinking, dietary habits, as well as personal and familial history of chronic liver diseases were obtained through standardized interviews based on structured questionnaires at the recruitment. Blood samples were also collected from 9688 (71%) study subjects and examined for the hepatitis B surface antigen (HBsAg). A total of 60 new HCC cases occurred giving an incidence rate of 83.3 per 100 000 person‐years. Cox's proportional hazards models were used to analyse multiple risk factors of HCC. In addition the HBsAg carrier status which showed a multivariate‐adjusted relative risk of 17.0, cumulative cigarette smoking, alcohol drinking quantity, vegetarian habit and low vegetable consumption were associated with the development of HCC. The multivariate‐adjusted relative risk was 1.8 for those who smoked 26 or more pack‐years of cigarettes compared with non‐smokers, 3.1 for those who drank alcohol 50 mL or more per day compared with those who were non‐drinkers or drank less than 50 mL per day, 2.5 for vegetarians compared with non‐vegetarians, as well as 4.6 and 2.6, respectively, for those who had a weekly vegetable consumption frequency of less than two meals and two to five meals compared with those who had a frequency of six or more meals.