Treatment Patterns and Survival Outcomes for Patients with Small Cell Carcinoma of the Bladder

Small cell carcinoma of the bladder (SCCaB) is a rare tumor without a standard treatment algorithm. Treatment patterns and survival outcomes from the National Cancer Database (NCDB) may provide insight into optimal treatment strategies.

To investigate the relationship between overall survival (OS) and treatment strategy.

This was an observational study of treatment-naïve patients who received treatment from 2004 to 2013. Patients with cT1-4aN0M0 SCCaB were identified from the NCDB, a hospital-based tumor registry that captures >70% of incident cancer cases in the USA.

Treatment strategies included local therapy alone, chemotherapy (CT), radiation therapy (RT), chemoradiation therapy (CRT), radical cystectomy (RC), and RC plus chemotherapy (RC+C).

OS was analyzed as a function of treatment modality adjusting for patient, demographic, and tumor-related factors. The Kaplan-Meier survival method, and the log-rank test and Cox regression were used for univariable and multivariable analyses.

We identified 856 patients with median follow-up of 18.3 mo. The median OS for the entire cohort was 20.7 mo (95% confidence interval [CI] 18.3-23.2) and estimated 3-yr and 5-yr OS were 37.5% and 28.2%, respectively. The most common treatment modality was CT (225 patients; 26.3%) followed by CRT (203 patients; 23.7%) and RC+C (201 patients; 23.5%). The median OS was 18.4 mo (95% CI 15.2-21.5) for CT, 34.1 mo (95% CI 22.5-45.8) for CRT, and 32.4 mo (95% CI 20.8-44.1) for RC+C. OS did not significantly differ between CRT and RC+C (p=0.42). On multivariable analysis, the best OS was associated with CRT (hazard ratio [HR] 0.41, 95% CI 0.32-0.53; p<0.0001) and RC+C (HR 0.45, 95% CI 0.34-0.59; p<0.0001).

RC+C and CRT are associated with better OS compared to monotherapy among patients with SCCaB.

Small cell carcinoma of the bladder is a rare and highly aggressive cancer. According to National Cancer Database data, radical cystectomy plus chemotherapy and chemoradiation therapy are associated with better overall survival compared to monotherapy.