Coffee and tea drinking and risk of cancer of the urinary tract in male smokers

Purpose: We evaluated the association of coffee and tea drinking with risk of the urinary tract cancer in Finnish men, with high coffee consumption, using data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Methods: The ATBC trial conducted from 1985 to 1993 enrolled 29,133 male smokers. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and confidence intervals (CIs), using men who drank more than 0 but less than 1 cup coffee/d and tea nondrinkers as our referent group for coffee and tea analyses, respectively. Results: During 472,402 person-years of follow-up, 835 incident cases of bladder cancer and 366 cases of renal cell carcinoma were ascertained. For bladder cancer, we observed no association for coffee consumption (HR >= 4 vs. >0 to <1 cups/d = 1.16, 95% CI = 0.86-1.56) and a borderline statistically significant inverse association for tea consumption (HR >= 1 vs. 0 cup/d = 0.77, 95% CI = 0.58-1.00). For renal cell carcinoma, we observed no association for coffee (HR >= 4 vs. >0 to <1 cups/d = 0.85, 95% CI = 0.55-1.32) or tea consumption (HR >= 1 vs. 0 cup/d = 1.00, 95% CI = 0.68-1.46). We found no impact of coffee preparation on coffee-cancer associations. Conclusions: Coffee drinking was not associated with urinary tract cancers risk. Further research on tea and bladder cancer is warranted. Published by Elsevier Inc.