Small cell carcinoma of the bladder: A population-based analysis of long-term outcomes after radical cystectomy and bladder conservation with chemoradiotherapy.

INTRODUCTION:We aimed to describe the oncological outcomes after radical cystectomy and chemo-radiation for localized small cell bladder cancer (SCBC). METHODS:This population-based analysis of localized SCBC from 1985-2018 in British Columbia included an analysis (analysis 1) of cancer-specific survival (CSS) and overall survival (OS) of patients treated with curative-intent radical cystectomy (RC) and radiation (RT), and an analysis (analysis 2) of CSS and OS in patients treated with RC and chemoRT consistent with the SCBC Canadian consensus guideline. RESULTS:Seventy-seven patients who were treated with curative intent were identified: 33 patients had RC and 44 had RT. For analysis 1, five-year OS was 29% and 39% for RC and RT, respectively (p=0.51), and five-year CSS was 35% and 52% for RC and RT, respectively (p=0.29). On multivariable analysis, higher Charlson comorbidity index (CCI) and the lack of neoadjuvant chemotherapy (NAC) were associated with worse OS, while higher CCI and Eastern Cooperative Oncology Group (ECOG) were associated with worse CSS. For analysis 2, five-year OS was 56% and 58% for the RC and chemoRT groups, respectively (p=0.90), and five-year CSS was 56% for RC and 71% for chemoRT (p=0.71). Four of 42 (9.5%) chemoRT patients had RC at relapse. CONCLUSIONS:SCBC is a rare entity with a poor prognosis. RC and chemoRT offer similar CSS and OS for localized SCBC, even when focusing the analysis on patients treated according to the modern consensus guidelines. NAC should be considered for eligible patients. Both chemoRT and RC treatment options should be discussed with patients with SCBC.