Cigarette smoking, alcohol drinking, and oral and pharyngeal cancer mortality in Japan

Abstract

To prospectively examine the association of cigarette smoking and alcohol drinking with oral and pharyngeal carcinogenesis, we analyzed data from a nation-wide large-scale cohort study in Japan. A total of 34 136 men and 43 711 women aged 40-79 years were included in the study. The Cox proportional hazard model was used to estimate the relative risk (RR) and 95% confidence interval (95% CI) of oral and pharyngeal cancer for smoking and drinking by sex, while adjusting for age, consumption of green tea, preference for salty foods, and consumption of green yellow vegetables. Current smokers were found to have a higher risk of death caused by oral and pharyngeal cancer compared with non-smokers in both sexes: the RR was 2.6 (95% CI: 1.0-6.7) in men and 8.2 (95% CI: 2.1-32.1) in women. Men who drank more than 46 g ethanol per day had an approximately threefold increased risk of oral and pharyngeal cancer. Simultaneous exposure to both factors was significantly associated with an elevated risk of oral and pharyngeal cancer (RR: 3.3, 95% CI: 1.1-9.6). The result supports the carcinogenic effect of cigarette smoking and alcohol drinking on the oral cavity and pharynx.