Towards Defining Follow-up Strategies for Patients with Primary Intermediate-risk Non-muscle-invasive Bladder Cancer

Area of Science:

• Urology
• Oncology
• Bladder Cancer Research

Background:

• Current European Association of Urology (EAU) guidelines categorize non-muscle-invasive bladder cancer (NMIBC) into four risk groups.
• A 2024 update introduced a specific follow-up schedule for intermediate-risk (IR) NMIBC, based on expert opinion and limited to primary low-grade or high-grade/grade 2 disease.
• There is a need to identify subgroups within IR-NMIBC requiring more intensive surveillance.

Purpose of the Study:

• To identify a subgroup of patients with intermediate-risk non-muscle-invasive bladder cancer (IR-NMIBC) who may benefit from more stringent follow-up protocols.
• To determine predictors of recurrence in IR-NMIBC.
• To refine risk stratification for IR-NMIBC patients.

Main Methods:

• Retrospective analysis of 2086 patients with IR-NMIBC using the World Health Organization 1973 grading scheme.
• Multivariable Cox-regression models to identify recurrence predictors.
• Dichotomization into low (IR-Low) and high (IR-High) recurrence risk groups based on identified predictors.
• Kaplan-Meier analysis for recurrence-free survival (RFS) and progression-free survival (PFS).

Main Results:

• Multifocality and tumor size ≥3 cm were significant predictors of higher recurrence risk, defining the IR-High group.
• The 3-year recurrence-free survival rate was significantly worse for the IR-High group (51%) compared to the IR-Low group (68%).
• The risk of progression was low in both groups (5-year PFS rate 96%), with no significant difference observed.

Conclusions:

• Tumor size and focality are more critical than grade for predicting recurrence in IR-NMIBC.
• Follow-up schedules for IR-NMIBC should be individualized based on recurrence risk.
• More stringent follow-up protocols are recommended for IR-NMIBC patients identified as higher risk for recurrence.