AUA 2018: Application of AUA Risk Stratification for NMIBC: Long-term Results in a Contemporary Single Institution Cohort

San Francisco, CA ( The EAU and AUA/SUO guidelines for non-muscle invasive bladder cancer (NMIBC), despite generally agreeing on most components of low, intermediate, and high-risk stratification, have subtle differences between the two guidelines. Broadly speaking, the risk group stratification is as follows:

UroToday_AUA 2018_Risk Stratification for NMIBC UroToday Zachary Klaassan MD
As noted above, patients with NMIBC represent a heterogeneous group of patients with variable risk of recurrence and progression. The recent AUA guideline for the management of NMIBC recommends risk stratification at the time of diagnosis [1]. Maria Velasquez, MD, and colleagues from the University Miami presented results of their application of the AUA risk stratification system to a contemporary group of patients with NMIBC with long-term follow up to analyze predictors of recurrence and progression. 

For this study, the authors retrospectively identified 400 patients with NMIBC treated at the University of Miami between 2007 and 2017. Descriptive statistics were used to compare groups by AUA risk strata. Subsequently, multivariable regression modeling was performed to determine predictors of recurrence and progression. Kaplan Meier survival analysis was performed to determine progression-free and recurrence-free survival stratified by risk group.  

Among these patients, 91.7% underwent BCG induction and maintenance therapy; 97% of patients received induction therapy and 46% of patients received at least 1 course of maintenance treatment. At diagnosis, there were 7% low risk, 24.5% intermediate risk and 67.3% high-risk patients. Over a median follow-up of 15.5 years, overall 78 (19.5%) patients progressed, 108 (27%) had disease recurrence, 38 (9.5%) underwent radical cystectomy, and 5 (1.25%) of patients died of bladder cancer. Among patients undergoing radical cystectomy, 10 (26.3%) did so secondary to disease progression and 28 (73%) secondary to multiple recurrences. 3-year progression free survival for low, intermediate, and high-risk patients was 97.1%, 85.2%, and 67.6%, respectively. 3-year recurrence-free survival for low, intermediate, and high-risk patients was 43.3%, 33.3%, and 20.1%, respectively. On multivariable analyses a significant predictor of recurrence was tumor size > 5 cm (HR 2.64, 95%CI 1.42 – 4.86), and significant predictors of progression were tumor stage CIS (HR 3.27, 95C%1.27 – 8.46) and mitomycin C as type of intravesical therapy given compared to BCG (HR 1.90 95%CI 1.02 – 3.55). Not surprisingly, both sizes>5 cm and Tis are components of high-risk stratification based on both EAU and AUA NMIBC guidelines.

The strength of the current study is the long, >15-year median follow-up, which is remarkable. However, like most institutional studies assessing outcomes of NMIBC, this study lacks long-term event rates such as radical cystectomy rates and mortality secondary to bladder cancer. The authors concluded that in this study of long-term follow-up of NMIBC patients, the AUA NMIBC risk groups appropriately stratify patients based on the likelihood of recurrence and progression. 

Presented By: Maria Velasquez, MD, University Of Miami Miller School of Medicine, Miami, FL
Co-Authors: Deukwoo Kwon, Nachiketh Soodana Prakash, Marcelo P. Barboza, Luis F Savio, Omer Kineish, Mahmoud Alameddine, Sanoj Punnen, Mark Gonzalgo, Dipen J Parekh, Chad R Ritch, Chad R Ritch, Miami, FL

1. Chang SS, Boorjian SA, Chou R, et al. Diagnosis and treatment of non-muscle invasive bladder cancer: AUA/SUO Guideline. J Urol 2016;196(4):1021-1029.

Written by:  Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre Twitter: @zklaassen_md at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA
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