Non-alcoholic beverages and risk of bladder cancer in Uruguay

Background: Bladder cancer is the fourth most frequent malignancy among Uruguayan men. A previous study from Uruguay suggested a high risk of bladder cancer associated with mate drinking. We conducted an additional case-control study in order to further explore the role of nonalcoholic beverages in bladder carcinogenesis. Methods: In the time period 1996 - 2000, 255 incident cases with transitional cell carcinoma of the bladder and 501 patients treated in the same hospitals and in the same time period were frequency matched on age, sex, and residence. Both cases and controls were face-to-face interviewed on occupation, tobacco smoking, alcohol drinking and intake of mate, coffee, tea, and soft drinks. Statistical analysis was carried out by unconditional multiple logistic regression. Results: Ever mate drinking was positively associated with bladder cancer ( odds ratio [ OR] 2.2, 95% confidence interval [CI] 1.2 - 3.9) and the risk increased for increasing duration and amount of mate drinking. Both coffee and tea were strongly associated with bladder cancer risk ( OR for coffee drinking 1.6, 95% CI 1.2 - 2.3; OR for tea drinking 2.3, 95% CI 1.5 - 3.4). These results were confirmed in a separate analysis of never-smokers. Conclusion: Our results suggest that drinking of mate, coffee and tea may be risk factors for bladder carcinoma in Uruguay.