Cigarette smoking and risk of prostate cancer in the Physicians' Health Study (United States)

Abstract

To assess whether cigarette smoking is associated with prostate cancer incidence or mortality, we analyzed a large cohort of 22,071 men, aged 40-84 at baseline, in the Physicians' Health Study. During an average of 12.5 years of follow-up, we documented 996 cases of prostate cancer, including 113 fatal cases. Men were categorized according to smoking status, total pack-years smoked, and duration of smoking. We used Cox proportional hazard models to estimate the relative risks associated with smoking. Compared to never smokers, the age-adjusted relative risks (RR) of total prostate cancer were 1.14 (95% confidence interval [CI] = 1.00-1.30) for past smokers, 1.10 (95% CI = 0.78-1.55) for current smokers of less than 20 cigarettes per day, and 1.10 (95% CI = 0.84-1.44) for current smokers of 20 or more cigarettes per day. Adjustment for body mass index, height, alcohol intake, and physical activity did not materially alter these findings. No significant association was observed in analyses of total pack-years smoked or duration of smoking. The results were similar for non-fatal and fatal prostate cancer. These data indicate no material association between cigarette smoking and prostate cancer incidence or mortality. (C) 2000 Wiley-Liss, Inc.