Background: Blacks are less likely than whites to develop bladder carcinoma. However, once they are diagnosed, black patients experience poorer survival. The authors investigated which factors were related to survival differences in black patients and white patients with bladder carcinoma stratified by extent of disease.
Methods: A population-based cohort of black patients with bladder carcinoma and a random sample of frequency-matched white patients with bladder carcinoma, stratified by age and gender, were identified through cancer registry systems in Atlanta, New Orleans, and San Francisco/Oakland. Patients had no previous cancer history and were ages 20-79 years at the time they were diagnosed with bladder carcinoma in 1985-1987. Medical records were reviewed at initial diagnosis, and 77% of patients were interviewed. Tumor grade, T classification, and other variables, including age, socioeconomic position, symptom duration, smoking history, and comorbidities, were recorded. Survival of black patients and white patients by extent of disease was modeled using Cox regression analysis.
Results: A greater proportion of black patients had histologic types of tumors that were associated with poorer survival. Among those with pure urothelial carcinoma, black patients had greater extent of disease at the time of diagnosis. Within specific extent-of-disease categories, there was some evidence of poorer survival for black patients with T2 tumors and strong evidence of poorer survival among those with T3 tumors compared with white patients. Black patients with muscle-invasive carcinoma who died within 6 months of diagnosis tended to present with life-threatening symptoms. Black patients and white patients did not differ with respect to diagnostic tests performed or therapy given.
Conclusions: Black patients with bladder carcinoma had poorer survival due to greater extent of disease at diagnosis and a higher proportion of more aggressive histologies compared with white patients. Within urothelial carcinomas, by extent of disease (clinical/pathologic stage) these black/white survival differences were limited to patients with muscle invasion (T2 and T3 tumors).