Fluid intake and the incidence of bladder cancer among middle-aged men and women in a three-county area of Western Washington

This population-based case-control study reports on the relationship between fluid intake and the incidence of bladder cancer among 262 bladder cancer cases from Western Washington and 405 controls identified through random-digit dialing. Cases were identified from the Surveillance, Epidemiology, and End Results (SEER) registry and were diagnosed between January 1987 and June 1990. All eligible subjects were Caucasian 45- to 65-year-old residents of King, Pierce, or Snohomish counties and completed a structured telephone interview. Analyses were conducted by logistic regression with adjustment for age, county, and smoking (current, former, never). Among women there was a positive association between total fluid intake and the incidence of bladder cancer [p (trend) = 0.02] and a moderate positive association between the use of decaffeinated coffee and the incidence of bladder cancer [p (trend) = 0.08]. Among men there was an inverse association between the consumption of regular soft drinks and the incidence of bladder cancer [p (trend)= 0.03]. No association was found between the incidence of bladder cancer and the intake of water, coffee, tea, diet soft drinks, alcohol, or liquids from tap for men or women. This study suggests that the intake of water and specific beverages is overall not associated with risks of bladder cancer. This study provides limited evidence of a positive association between total fluid intake and bladder cancer among women.