Bladder Cancer Mortality in the United States: A Geographic and Temporal Analysis of Socioeconomic and Environmental Factors

Purpose: We assessed the association of temporal, socioeconomic and environmental factors with bladder cancer mortality in the United States. Our hypothesis was that bladder cancer mortality is associated with distinct environmental and socioeconomic factors with effects varying by region, race and gender. Materials and Methods: NCI (National Cancer Institute) age adjusted, county level bladder cancer mortality data from 1950 to 2007 were analyzed to identify clusters of increased bladder cancer death using the Getis-Ord Gi* statistic. Socioeconomic, clinical and environmental data were assessed using geographically weighted spatial regression analysis adjusting for spatial autocorrelation. County level socioeconomic, clinical and environmental data were obtained from national databases, including the United States Census, CDC (Centers for Disease Control and Prevention), NCHS (National Center for Health Statistics) and County Health Rankings. Results: Bladder cancer mortality hot spots and risk factors for bladder cancer death differed significantly by gender, race and geographic region. From 1996 to 2007 smoking, unemployment, physically unhealthy days, air pollution ozone days, percent of houses with well water, employment in the mining industry and urban residences were associated with increased rates of bladder cancer mortality (p < 0.05). Model fit was significantly improved in hot spots compared to all American counties (R-2 = 0.20 vs 0.05). Conclusions: Environmental and socioeconomic factors affect bladder cancer mortality and effects appear to vary by gender and race. Additionally there were temporal trends of bladder cancer hot spots which, when persistent, should be the focus of individual level studies of occupational and environmental factors.