Effects of Different Organ Metastases on the Prognosis of Stage IV Urothelial Carcinoma of the Bladder

OBJECTIVE: To assess the prognosis of stage IV metastatic urinary bladder urothelial carcinoma (UBUC) at initial diagnosis and determine prognostic factors based on distant organ metastasis. METHODS: A retrospective cohort analysis of UBUC was conducted based on the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were used to determine the variables associated with overall survival (OS). Kaplan–Meier curves were used to compare survival curves among different groups. RESULTS: A total of 3103 patients with stage IV UBUC were selected for analysis. The number of distant organ metastatic sites independently predicted the OS. The OS was not different in other metastatic sites when bone metastasis was used as a reference (P > 0.05). However, the OS was shorter for a single metastatic site (P < 0.001) and multiple metastatic sites when metastasis was not used as a reference (P < 0.001). Multivariable Cox regression analysis indicated that low survivorship was independently associated with no surgery for the entire cohort and patients with only one metastatic organ. Sex (P = 0.019) and grade (P = 0.046) were the independent risk factors for patients with only one metastatic organ. CONCLUSIONS: These results show that the prognosis of stage IV metastatic UBUC is not different between any single metastatic organ. The prognosis of stage IV metastatic UBUC depends on the number of distant organ metastasis. This study determined some predictors of survival and thus may help therapists to choose appropriate treatment strategies for metastatic UBUC.