Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Department of Health and Human Services, Bethesda, MD, USA.
Glucuronide conjugates of 4-aminobiphenyl and its N-hydroxy metabolite can be rapidly hydrolyzed in acidic urine to undergo further metabolic activation and form DNA adducts in the urothelium. We conducted a large multicenter case-control study in Spain to explore the etiology of bladder cancer, and evaluated the association between urine pH and bladder cancer risk, alone and in combination with cigarette smoking. 712 incident urothelial cell carcinoma cases and 611 hospital controls directly measured their urine pH with dipsticks twice a day (first void in the morning and early in the evening) during four consecutive days two weeks after hospital discharge. We found that a consistently acidic urine pH ≤ 6.0 was associated with an increased risk of bladder cancer (OR=1.5, 95%CI: 1.2 - 1.9), compared to all other subjects. Further, risk estimates for smoking intensity and risk of bladder cancer among current smokers tended to be higher for those with a consistently acidic urine (OR=8.8, 11.5, and 23.8), compared to those without (OR=4.3, 7.7 and 5.8, respectively, for 1-19, 20-29, 30+ cigarettes per day; p(interaction) for 30+ cigarettes per day =0.024). These results suggest that urine pH, which is determined primarily by diet and body surface area, may be an important modifier of smoking and risk of bladder cancer.
Written by:
Alguacil J, Kogevinas M, Silverman D, Malats N, Real FX, García-Closas M, Tardón A, Rivas M, Torà M, García-Closas R, Serra C, Carrato A, Pfeiffer R, Fortuny J, Samanic C, Rothman N. Are you the author?
Reference: Carcinogenesis. 2011 Mar 14. Epub ahead of print.
doi: 10.1093/carcin/bgr048
PubMed Abstract
PMID: 21402590
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