Urothelial Carcinoma Versus Squamous Cell Carcinoma of Bladder: Is Survival Different With Stage Adjustment?

Objectives To determine whether the survival of patients with squamous cell carcinoma (SCC) is different from that of patients with urothelial carcinoma, after adjusting for stage, grade, demographic factors, and the initial treatment. Methods Information on bladder cancer cases diagnosed from 1988 to 2003 was obtained from the Surveillance, Epidemiology, and End Results database. The tumors were classified by histologic type, grade, and American Joint Committee on Cancer (AJCC) stage. Other covariates included age, sex, race, and information on the initial treatment (cystectomy and radiotherapy). The outcome variables examined were all-cause and bladder cancer-specific mortality within 2 years of diagnosis. Covariate-adjusted mortality differences were computed within each stage using the modified least squares model. Results SCC histologic features were an independent predictor of all-cause and bladder cancer-specific mortality among patients with AJCC Stage I and II tumors who did not undergo cystectomy as a part of their initial treatment and among patients with AJCC Stage III and IV regardless of whether cystectomy was performed. SCC histologic features were not associated with increased mortality among patients with AJCC Stage I and II tumors treated with cystectomy. Conclusions SCC appears to be more aggressive than urothelial carcinoma after adjusting for stage and other prognostic factors, except for cases in which the tumor was confined to the bladder wall and the bladder was removed as a part of the initial treatment.