Impact of Different Surveillance Intervals on Recurrence and Progression in Intermediate-Risk Non-Muscle-Invasive...

To evaluate recurrence and progression outcomes in patients with intermediate-risk non-muscle-invasive bladder cancer (IR-NMIBC) undergoing different surveillance protocols, and to assess the impact of follow-up intensity on oncologic outcomes.

We retrospectively reviewed patients who underwent transurethral resection of bladder tumor between 2010 and 2024 and met the 2021 EAU criteria for intermediate-risk NMIBC. Patients were stratified by surveillance interval (3, 4, or 6 months). Primary endpoints were tumor recurrence and progression, with recurrence-free survival (RFS) and progression-free survival (PFS) as secondary endpoints.

A total of 203 patients were included in the study. At 24 months of follow-up, recurrence rates (39%, 45%, and 53%) and progression rates (12%, 14%, and 26%) did not differ significantly among the 3-, 4-, and 6-month surveillance groups, respectively (p = .2 and p = .06). Kaplan-Meier analyses showed no statistically significant difference in RFS among the groups, whereas PFS was significantly lower in the 6-month surveillance group (log-rank p = .02). In subgroup analyses, PFS did not differ among patients with low-grade tumors but was significantly lower with a 6-month surveillance interval in patients with high-grade tumors (log-rank p = .04).

Surveillance strategies for patients with IR-NMIBC should be individualized, particularly for high-grade tumors, as extended intervals may increase the risk of progression. Further studies could help refine risk-adapted follow-up schedules.