It has been hypothesized that high fluid intake may reduce contact time between carcinogens and bladder epithelial and consequently reduce carcinogenesis. Epidemiologic studies examining fluid intake and bladder cancer have been extremely inconsistent, ranging from strong inverse to strong positive associations. We reevaluated the association between fluid intake and bladder cancer among 47,909 participants in the prospective Health Professionals Follow-up Study over a period of 23 years. 823 incident bladder cancer cases were diagnosed during follow-up (1986–2008). Information on fluid intake was collected using the food-frequency questionnaire at the baseline and every four years thereafter. Cox proportional hazard regression analysis was used to adjust for risk factors for bladder cancer. Total fluid intake was inversely associated with bladder cancer when the analysis was based on the baseline diet (RR: 0.76, 95% CI: 0.60–0.97, comparing the highest total daily fluid intake quintile (>2531 ml per day) to the lowest quintile (<1290 ml per day, p-trend = 0.01). However, no association was detected when the analysis was based on recent diet or cumulative updated diet. The updated analysis for total fluid intake and bladder cancer was attenuated compared to the original findings from the first 10-year follow-up period.
Citation Information: Cancer Prev Res 2011;4(10 Suppl):B108.