Prognostic Nomogram, Demographics and Comparative Analysis of Urinary Bladder Small Cell and Large Cell Neuroendocrine Carcinoma.

Background: This retrospective study aims to provide a comprehensive analysis of the demographics, survival rates, and therapeutic approaches of small-cell neuroendocrine carcinoma (SCNEC) and large-cell neuroendocrine carcinoma (LCNEC) while highlighting key differences compared to common urinary bladder cancers.

Methods: Our analysis utilized the Surveillance, Epidemiology, and End Results database (SEER), and data was collected from 2000-2020.

Results: A total of 1040 cases of urinary bladder SCNEC and LCNEC were identified. Most patients were over the age of 80 years (33.2%), male (78.9%), and Caucasian (83.6%). Most tumors were over 4.1cm (47.4%) and in the lateral wall of the bladder (37.8%). The overall 5-year survival was 22.1% (95% confidence interval (95% CI):20.7-23.5). The 5-year survival by sex was greatest for the female population (28.0%; (95% CI: 24.5-35.0). For treatment modality, the 5-year survival for each was as follows: surgery, 12.5% (95% CI: 10.5-14.5) multimodality therapy (surgery and chemotherapy), 31.1% (95% CI: 28.5-33.7) and combination (surgery, chemotherapy, and radiation) 32.8% (95% CI: 29.1-36.5). On multivariable analysis, positive nodal status hazar ratio (HR)(HR3.65 [95% CI: 2.34-5.71], P < .001) was identified as a negative predictor for survival, and increasing age was nearly significant for a worse prognosis (P = .052). The prognostic nomogram that was created to predict patient survivability mirrored the findings from the statistical analysis, with a statistically significant difference found in race, treatment modality, and tumor stage.

Conclusions: SCNEC and LCNEC are rare yet highly intrusive subtypes of bladder cancer that usually affect Caucasian males over the age of 80 years old. The study identifies older age and positive nodal status as adverse prognostic indicators. Our findings offer crucial insights that can inform future clinical guidelines and serve as a basis for more tailored treatment strategies for these aggressive subtypes of bladder cancer.