Survival and Analysis of Prognostic Factors for Bladder Malignancies in Children and Adolescents: A Population-based Study.

Objective: To explore the clinicopathological features and prognosis of pediatric patients with malignant bladder tumors in a population-based cohort.

Methods: The database Surveillance, Epidemiology, and End Results was used to evaluate all pediatric patients diagnosed with malignant bladder tumors between 1975 and 2018. The log-rank test was used to compare survival curves. Kaplan-Meier estimations were used to create survival curves based on various parameters. The Cox proportional hazards model was utilized to determine the factors that were independently related to mortality.

Results: A total of 263 children and adolescents with bladder malignancies were assessed. Papillary urothelial neoplasms of low malignant potential were the most frequent histologic subtype (35.1%), while embryonal rhabdomyosarcoma was more common during the first decade of life. Survival rates varied significantly by age at diagnosis, with older patients showing better outcomes. When compared to other subtypes, papillary urothelial neoplasms of low malignant potential had the highest overall survival rates (3- and 5-year were 99.2% and 98.3%, respectively). Multivariate analysis of the entire cohort showed that Surveillance, Epidemiology, and End Results stage and surgery were significant independent predictors of progression to disease-specific death in this model.

Conclusion: Bladder malignancies are rare in children and adolescents. The prognosis for them varies. The localized stage was independently associated with superior survival and surgery could extend survival time.