Characterization and Outcomes of Small Cell Carcinoma of the Bladder Using the Surveillance, Epidemiology, and End Results Database

Abstract

To utilize the Surveillance, Epidemiology, and End Results Database to analyze clinical features, treatment, and survival outcomes of patients with small cell carcinoma of the bladder in a large population-based sample. Because of its rarity, prior reports are primarily limited to small single-institution studies. We identified patients of any age who were diagnosed with small cell carcinoma of the bladder between 1988 and 2007. Kaplan-Meier and Cox regression analysis were used to compare overall survival (OS) and urinary bladder-specific survival. A total of 663 patients were identified. Most patients had either stage II (38.8%) or stage IV (35.4%) disease. The median OS for all patients was 12 months [95% confidence interval (CI), 10.9-13.1]. After excluding those patients who presented with distant metastatic disease or for whom it was unknown whether or not they received any treatment, there were no significant differences in survival between those that received cystectomy (median survival, 21 mo; 95% CI, 14.3-27.7) compared with those who underwent external beam radiation (median survival, 17 mo; 95% CI, 13.4-20.6). On multivariate analysis, both cystectomy (hazard ratio, 0.53; 95% CI, 0.4-0.71; P < 0.001) and radiation (hazard ratio, 0.66; 95% CI, 0.5-0.88; P=0.005) were associated with improved survival. Small cell carcinoma of the bladder is a rare but aggressive malignancy with poor OS. For those who present without widespread metastatic disease, treatment with either cystectomy or radiation appears to improve survival. Further prospective studies are needed to determine the best approach for treatment of these patients.