Survival of Contemporary Patients With Non-metastatic Small-cell Carcinoma of Urinary Bladder, According to Alternative Treatment Modalities.

Background: The objective of this study was to test the effect of chemotherapy and/or radical cystectomy (RC) and/or radiotherapy (RT) on survival of patients with non-metastatic small-cell carcinoma of the urinary bladder (SCCUB).

Materials And Methods: Within the Surveillance, Epidemiology, and End Results registry (2001-2016), we identified patients with non-metastatic (T1-4, N0, M0) SCCUB. Treatment was defined as: chemotherapy alone, chemotherapy + RC, and chemotherapy + RT. Temporal trends, cumulative incidence plots, and multivariable competing risks regression models were used.

Results: Of 595 patients with SCCUB, 230 (38.5%), 159 (27%), and 206 (34.5%) were treated with chemotherapy alone, chemotherapy + RC, and chemotherapy + RT, respectively. The rates of chemotherapy + RC increased (estimated annual percentage changes [EAPC], +5.9%; P = .002). Conversely, chemotherapy alone (EAPC, -1.7%; P = .1) and chemotherapy + RT rates decreased (EAPC: -2.2%; P = .08). Overall, 5-year cancer-specific mortality (CSM) rates were 44%, 29%, and 40% for patients treated with chemotherapy alone, chemotherapy + RC, and chemotherapy + RT, respectively (P = .004). Relative to chemotherapy alone, patients treated with chemotherapy + RC experienced lower CSM (hazard ratio, 0.5; P < .001). Conversely, patients treated with chemotherapy + RT did not exhibit any CSM benefit (hazard ratio, 0.8; P = .2), when compared with chemotherapy alone.

Conclusion: In contemporary patients with SCCUB with non-metastatic disease, the rates of chemotherapy + RC are increasing. Conversely, the rates of combined chemotherapy with RT and chemotherapy alone are decreasing. These patterns of treatment are in agreement with better cancer control in patients with SCCUB. In consequence, until more robust data become available, the combination of chemotherapy and RC should represent the recommended treatment strategy.