Radiation Therapy as Definitive Local Treatment in Patients with Small Cell Carcinoma of the Bladder: Does total dose matter? A National Cancer Database Analysis

Abstract

To determine whether total radiation dose correlates with survival outcomes for patients with small cell carcinoma of the bladder (SCCB). We queried the National Cancer Database (NCDB) for patients with limited stage SCCB undergoing multimodality treatment and retrospectively analyzed survival outcomes according to total radiation dose received. Our cohort included 192 patients that received either chemoradiation (183) or radical cystectomy with chemoradiation (9), with a median follow-up of 23.9 months. Patients aged 41-75 receiving a total radiation dose of 54 Gy or greater had a statistically significant improvement in overall survival compared to those receiving less than 54 Gy, with a median overall survival of 68.1 months (95% confidence interval [CI] 43.8 - 92.3 months) compared to 25.9 months (95% CI 18.9 - 32.9 months) (p < 0.05). There was no statistically significant difference in outcomes for patients receiving between 54 and 60 Gy compared to those receiving 60 Gy or higher. There was also no difference in outcomes based on total radiation dose for patients over 75 years old, even when limiting analysis to patients with a Charlson-Deyo comorbidity index score of 0. For patients aged 75 or younger with limited stage SCCB, total radiation dose of 54 Gy or greater may be associated with better overall survival.