Coffee consumption, genetic susceptibility and bladder cancer risk.
Villanueva CM,
Silverman DT,
Murta-Nascimento C,
Malats N,
Garcia-Closas M,
Castro F,
Tardon A,
Garcia-Closas R,
Serra C,
Carrato A,
Rothman N,
Real FX,
Dosemeci M,
Kogevinas M.
Centre for Research in Environmental Epidemiology (CREAL), PRBB Building, Doctor Aiguader, 88, 08003, Barcelona, Spain. cvillanueva@creal.cat
OBJECTIVE: We evaluated the bladder cancer risk associated with coffee consumption in a case-control study in Spain and examined the gene-environment interactions for genetic variants of caffeine-metabolizing enzymes. METHODS: The analyses included 1,136 incident cases with urothelial carcinoma of the urinary bladder and 1,138 controls. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for area, age, gender, amount of cigarette smoking, and years since quitting among former smokers. RESULTS: The OR (95% CI) for ever consumed coffee was 1.25 (0.95-1.64). For consumers of 1, 2, 3, and 4 or more cups/day relative to never drinkers, OR were, respectively, 1.24 (0.92-1.66), 1.11 (95% CI 0.82-1.51), 1.57 (1.13-2.19), and 1.27 (0.88-1.81). Coffee consumption was higher in smokers compared to never smokers. The OR for drinking at least 4 cups/day was 1.13 (0.61-2.09) in current smokers, 1.57 (0.86-2.90) in former smokers, and 1.23 (0.55-2.76) in never smokers. Gene-coffee interactions evaluated in NAT2, CYP1A2, and CYP2E1-02 and CYP1A1 were not identified after adjusting for multiple testing. CONCLUSION: We observed a modest increased bladder cancer risk among coffee drinkers that may, in part, be explained by residual confounding by smoking. The findings from the gene-coffee interactions need replication in further studies.
PMID: 18798002 [PubMed - indexed for MEDLINE]