Surveillance for Nonmuscle Invasive Bladder Cancer: Identifying the Point of Diminishing Returns

Area of Science:

• Urology
• Oncology
• Epidemiology

Background:

• Nonmuscle-invasive bladder cancer (NMIBC) requires long-term monitoring for recurrence.
• Understanding recurrence patterns is crucial for optimizing follow-up strategies.

Purpose of the Study:

• To characterize first and second recurrence patterns in NMIBC patients.
• To evaluate the potential for adjusting monitoring intensity based on recurrence-free intervals.

Main Methods:

• A cohort of 386 NMIBC patients diagnosed between 1995-1996 in Stockholm County was followed for 26 years.
• Microsimulation modeling was employed, using logistic regressions, Kaplan Meier curves, and Cox models to predict recurrence and progression.
• Data included clinical and pathological information, with simulated outcomes for 10,000 patients.

Main Results:

• Median time to first recurrence was 300 days.
• Over 15 years, first recurrence rates were 56.6% (low-risk), 62.8% (intermediate-risk), and 48.7% (high-risk), with associated muscle-invasive progression rates of 2.2%, 4.3%, and 14.3%, respectively.
• Second recurrence rates after initial recurrence were 70.7% (low), 75.7% (medium), and 84.7% (high risk). First recurrences were rare after 9 years.

Conclusions:

• Patients with NMIBC who remain recurrence-free for 5 years may be candidates for less intensive surveillance.
• This approach could potentially reduce healthcare burden without compromising patient outcomes.