Survival Outcomes and Prognostic Factors of Small Cell Carcinoma of the Kidney and Upper Urinary Tract: A SEER Database Analysis

Abstract

Objective: Small cell carcinomas of the kidney (SCCK) and the upper urinary tract (SCC UUT) are exceedingly rare and aggressive malignancies. This study aimed to compare survival outcomes of these two conditions using a large population-based database.Materials and Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) database (2000–2022) were analysed. Patients with histologically confirmed SCCK (n = 41) and SCC UUT (n = 54) were included. Clinicopathological variables and treatment modalities were evaluated. Cancer-specific survival (CSS) was estimated using the Kaplan–Meier method and Cox proportional hazards models were employed to identify independent prognostic factors.Results: The study cohort consisted of 95 patients. Patients with SCCK exhibited significantly higher rates of distant metastasis than the UUT group (58.5% vs. 40.7%, p = 0.029). The median CSS was 9 months for the UUT group and 6 months for the kidney group (p = 0.068). Multivariate analysis in the kidney group identified surgical intervention (HR: 0.18, p