Cigarette smoking and risk of prostate cancer in the physicians' health study (United States)

To assess whether cigarette smoking is associated with prostate cancer inci dence 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 fa tal cases. Men were categorized according to smoking status, total pack-yea rs smoked, and duration of smoking. We used Cox proportional hazard models to estimate the relative risks associated with smoking. Compared to never s mokers, 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, an d 1.10 (95% CI = 0.84-1.44) for current smokers of 20 or more cigarettes pe r day. Adjustment for body mass index, height, alcohol intake, and physical activity did not materially alter these findings. No significant associati on was observed in analyses of total pack-years smoked or duration of smoki ng. The results were similar for non-fatal and fatal prostate cancer. These data indicate no material association between cigarette smoking and prosta te cancer incidence or mortality. Int. J. Cancer 87: 141-144, 2000, (C) 200 0 Wiley-Liss. Inc.