Background: Studies have found that women diagnosed with bladder cancer have lower 5-year survival rates than men. Women are diagnosed at later stages of disease, however this disparity persists once rates are adjusted for stage at diagnosis. Participants: To assess the influence of socio-demographic characteristics on survival differences, we analyzed data from 19,021 male and 6,693 female transitional cell bladder cancer patients diagnosed between 1991 and 1999 from the SEER-Medicare database. Methods: Cox Proportional Hazards models were constructed to assess stage-specific 5-year survival adjusting for age, race, number of co-morbid conditions, and the percent of the patients' census tract living below the poverty line ('ecologic' socioeconomic status). Results: Among those diagnosed with stage 4 disease, women have significantly lower 5-year survival than men, adjusting for age, race, number of co-morbidities, and 'ecologic' socioeconomic status [Hazard Ratio (HR) =1.36, 95% Confidence Interval (CI): 1.21 - 1.52]. However, there were no significant gender differences in 5-year survival among those diagnosed with stage 1, 2, or 3 bladder cancer after adjusting for socio-demographic characteristics. Conclusion: The results of the present study suggest differences in socio-demographic characteristics account for much of the previously observed gender differences in 5-year survival, although none of the socio-demographic characteristics examined explained the persistent gender survival disparity among those diagnosed with stage 4 disease. Improving bladder cancer survival among women should be approached from two fronts: 1) striving to improve earlier diagnosis, and 2) conducting additional research to assess which factors explain the observed gender disparity in survival among those diagnosed with stage 4 disease.
[Fifth AACR International Conference on Frontiers in Cancer Prevention Research, Nov 12-15, 2006]