Urinary pH, cigarette smoking and bladder cancer risk

• Published in: Carcinogenesis (New York) Vol. 32; no. 6; pp. 843 - 847
• Main Authors: ALGUACIL, Juan, KOGEVINAS, Manolis, SERRA, Consol, CARRATO, Alfredo, PFEIFFER, Ruth M, FORTUNY, Joan, SAMANIC, Claudine, ROTHMAN, Nathaniel, SILVERMAN, Debra T, MALATS, Núria, REAL, Francisco X, GARCIA-CLOSAS, Montserrat, TARDON, Adonina, RIVAS, Manuel, TORA, Montserrat, GARCIA-CLOSAS, Reina
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-06-2011
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Carcinogenesis, carcinogens and anticarcinogens; Carcinoma, Transitional Cell - etiology; Carcinoma, Transitional Cell - urine; Case-Control Studies; Female; Humans; Hydrogen-Ion Concentration; Male; Medical sciences; Middle Aged; Molecular Epidemiology; Nephrology. Urinary tract diseases; Odds Ratio; Risk Factors; Smoking - adverse effects; Tobacco, tobacco smoking; Toxicology; Tumors; Tumors of the urinary system; Urinary Bladder - pathology; Urinary Bladder Neoplasms - etiology; Urinary Bladder Neoplasms - urine; Urinary system involvement in other diseases. Miscellaneous; Urinary tract. Prostate gland; Young Adult; Cigarette; Urine; Tobacco; Urinary system disease; Risk factor; Tobacco smoking; pH; Bladder disease; Urinary tract disease; Malignant tumor; Bladder cancer; Cancer
• ISSN: 0143-3334; 1460-2180
• DOI: 10.1093/carcin/bgr048

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. In total, 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 2 weeks after hospital discharge. We found that a consistently acidic urine pH ≤6.0 was associated with an increased risk of bladder cancer [odds ratio (OR) = 1.5, 95% confidence interval (CI): 1.2-1.9] compared with all other subjects. Furthermore, 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 with those without (OR = 4.3, 7.7 and 5.8, respectively, for 1-19, 20-29 and 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.