Predicting recurrence and progression in NMIBC: A multi-event and temporal analysis approach

Area of Science:

• Urology
• Oncology
• Cancer Research

Background:

• Non-muscle invasive bladder cancer (NMIBC) constitutes 70-80% of bladder cancer cases.
• Bacillus Calmette-Guérin (BCG) therapy is standard, but 30% of patients do not respond, with high recurrence and progression rates.
• Existing research often overlooks the recurrent nature of NMIBC.

Purpose of the Study:

• To identify key factors influencing recurrence and progression in NMIBC patients treated with BCG.
• To analyze the complex dynamics of disease recurrence and progression using advanced statistical models.
• To differentiate recurrence patterns between intermediate-risk (IR) and high-risk (HR) NMIBC categories.

Main Methods:

• Retrospective analysis of 385 NMIBC patients treated with BCG (2012-2020).
• Stratification into EAU intermediate-risk (IR) and high-risk (HR) groups.
• Application of multi-event analyses (Cox proportional hazards, Prentice-Williams-Peterson Total Time) and multinomial logistic regression for temporal recurrence dynamics.

Main Results:

• Multifocality and prior bladder cancer history predict recurrence (HR=2.07, P=0.001; HR=1.72, P=0.008).
• High-risk (HR) patients showed significantly higher progression to muscle-invasive bladder cancer (MIBC) (13.1% vs. 4.5%, P=0.017).
• HR patients had increased odds of advanced recurrence (pT2 or higher; OR=2.71, P=0.001); late high-grade recurrences posed similar risks to early refractory tumors.

Conclusions:

• NMIBC recurrence dynamics are heterogeneous, with IR patients experiencing predominantly low-grade recurrences.
• HR patients face a persistent risk of high-grade and advanced-stage disease progression.
• Findings support personalized surveillance and bladder-preserving therapeutic strategies for HR NMIBC patients.