Survival of Metastatic Urothelial Carcinoma of Urinary Bladder According to Number and Location of Visceral Metastases

Objective: To test the association between number as well as locations of organ-specific metastatic sites and overall survival (OS) in systhemic-therapy exposed metastatic urothelial carcinoma of urinary bladder (mUCUB) patients. Methods: Within Surveillance, Epidemiology and End Results database (2010-2020), all systhemic therapy-exposed mUCUB patients were identified. Kaplan-Meier and multivariable Cox regression (CRM) models first addressed OS in patients according to number of metastatic organ-locations: solitary versus 2 versus 3 or more. Subsequently, separate analyses stratified according to location type were completed in patients with solitary metastatic organ-location as well as in patients with 2 metastatic organ-locations. Results: Of 1,310 mUCUB, 1,069 (82%) harbored solitary metastatic organ-location versus 193 (15%) harbored 2 separate metastatic organ-locations versus 48 (3%) harbored 3 or more metastatic organ-locations. Median OS decreased with increasing number of metastatic organ-locations (solitary vs. 2 vs. 3 or more, P < .0001). In multivariable CRM, relative to solitary metastatic organ-location, 2 (HR: 1.57, 95 Confidence interval [CI], 1.33-1.85) as well as 3 or more (HR: 1.69, 95% CI, 1.23-2.31) metastatic organ-locations independently predicted higher overall mortality (OM) (P = .001). In patients with solitary metastatic organ-location, brain metastases independently predicted higher OM (HR 1.67; 95% CI, 1.05-2.67; P = .03) than other locations. In patients with 2 metastatic organ-locations, no differences in OM were recorded according to organ type location. Conclusion: In systemic therapy exposed mUCUB, number of metastatic organ-locations (solitary vs. 2 vs. 3 or more), independently predicted increasingly worse prognosis. In patients with solitary metastatic organ-location, brain purported worse prognosis than others.