Abstract 634: Coffee and tea drinking and risk of cancer of the urinary tract in male smokers
Authors: Hashemian Maryam , Sinha Rashmi , Murphy Gwen , Weinstein Stephanie , Liao Linda M. , Freedman Neal , Abnet Christian C. , Albanes Demetrius , Loftfield Erikka 
Published: August 2019

Introduction: The association of coffee and tea drinking with risk of the urinary tract cancer is unclear. We evaluated these associations in Finnish men with high coffee consumption, using data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which included information on coffee preparation method.

Methods: The ATBC trial conducted from 1985 to 1993, enrolled 29,133 male smokers. Among 26,841 men with data on coffee and tea intake and without renal failure or extreme caloric intake, we used multivariable Cox proportional hazards regression models to estimate hazard ratios (HRs) and confidence intervals (CIs) for associations of coffee and tea consumption with incident bladder cancer and renal cell carcinoma (RCC). We used those who drank &gt;0 but &lt;1 cup coffee/day as our referent group for coffee analyses, and non-drinkers of tea for tea analyses.

Results: During 472,402 person-years of follow-up (median 17.6 years), 835 incident cases of bladder cancer and 366 cases of RCC were ascertained. Approximately 98% of participants reported drinking coffee and 36% reported drinking tea at baseline. Mean consumption among drinkers was 2.3 cups/day for coffee and 0.7 cups/day for tea. Participants who reported heavier coffee drinking tended to be younger, smoke more cigarettes daily, drink less alcohol and less tea, be less educated, have a lower prevalence of hypertension, and consume more calories and vegetables but less fruit daily. Participants who reported heavier tea drinking tended to have smoked for fewer years, be more educated, drink less coffee, have a higher prevalence of hypertension, and consume more calories, fruits, and vegetables per day. We observed no statistically significant associations for coffee intake with either bladder cancer (HR ≥4 vs &gt;0 to &lt;1 cups/day = 1.16, 95% CI=0.86-1.56) or RCC (HR ≥4 vs &gt;0 to &lt;1 cups/day = 0.85, 95% CI=0.55-1.32) risk, and a non-significant inverse association between tea consumption and bladder cancer (HR ≥1 vs 0 cup/day=0.77, 95% CI=0.58-1.00), but not RCC risk (HR ≥1 vs 0 cup/day=1.00, 95% CI=0.68-1.46). Smoking status, defined using pack-years, appeared to modify bladder cancer association with both coffee and tea (P interaction=0.005 and &lt;0.001, respectively), but not the coffee- and tea-RCC associations (P interaction=0.50 and =0.08, respectively). However, analyses stratified by pack-years revealed non-significant associations. Among 20,603 men with information on preparation method, 71% drank filtered coffee, 21% drank boiled coffee, and 8% drank instant coffee or were not coffee drinkers. We found no impact of coffee preparation on the coffee-cancer associations.

Conclusion: Coffee drinking was not associated with risk of bladder cancer or RCC. Further research on tea and bladder cancer, in populations with a high prevalence of tea drinking, are warranted.

Citation Format: Maryam Hashemian, Rashmi Sinha, Gwen Murphy, Stephanie Weinstein, Linda M. Liao, Neal Freedman, Christian C. Abnet, Demetrius Albanes, Erikka Loftfield. Coffee and tea drinking and risk of cancer of the urinary tract in male smokers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 634.