Use and Validation of the AUA/SUO Risk Grouping for Nonmuscle Invasive Bladder Cancer in a Contemporary Cohort

Abstract

Purpose: We applied nonmuscle invasive bladder cancer AUA (American Urological Association)/SUO (Society of Urologic Oncology) guidelines for risk stratification and analyzed predictors of recurrence and progression.

Materials and methods: We retrospectively reviewed the records of 398 patients with nonmuscle invasive bladder cancer treated between 2001 and 2017. Descriptive statistics were used to compare AUA/SUO risk groups. Predictors of recurrence and progression were determined by multivariable regression. Kaplan-Meier analysis was done, a Cox proportional hazards regression model was created and time dependent AUCs were calculated to determine progression-free and recurrence-free survival by risk group.

Results: Median followup was 37 months (95% CI 35-42). Of the patients 92% underwent bacillus Calmette-Guérin induction and 46% received at least 1 course of maintenance treatment. Of the patients 11.5% were at low, 32.5% were at intermediate and 55.8% were at high risk. In patients at low, intermediate and high risk the 5-year progression-free survival rate was 93%, 74% and 54%, and the 5-year recurrence-free survival rate was 43%, 33% and 23%, respectively. Kaplan-Meier analysis was done to stratify high grade Ta 3 cm or less tumor recurrence-free and progression-free survival in the intermediate vs the high risk group. Relative to low risk, classification as intermediate and as high risk was an independent predictor of progression (HR 9.7, 95% CI 2.23-42.0, p <0.01, and HR 36, 95% CI 8.16-159, p <0.001, respectively). Recurrence was more likely in patients at high risk than in those at low risk (HR 2.03, 95% CI 1.11-3.71, p=0.022). For recurrence and progression the 1-year AUC was 0.60 (95% CI 0.546-0.656) and 0.68 (95% CI 0.622-0.732), respectively.

Conclusions: The AUA/SUO nonmuscle invasive bladder cancer risk classification system appropriately stratifies patients based on the likelihood of recurrence and progression. It should be used at diagnosis to counsel patients and guide therapy.

Keywords: classification; local; neoplasm recurrence; progression-free survival; risk; urinary bladder neoplasms.