Effect of Bacillus Calmette-Guérin Instillation Timing on Oncological Survivals After Transurethral Resection of Bladder Tumor.

Objective: To investigate whether the timing of bacillus Calmette-Guerin instillation (TTBCG), which plays a key role in treating non-muscle invasive bladder cancer (NMIBC), after transurethral resection of bladder tumor (TURBT) affects oncologic outcomes.

Methods: Patient data obtained from the Urologic Cancer Database-Bladder (UroCaD-B) of Turkish Uro-oncology Association (TUOA) were evaluated. Data from 292 patients from 12 centers with primary T1HG treated with TURBT and maintenance BCG between 2003 and 2023 were retrospectively analyzed. The population was subdivided according to TTBCG, while recurrence-free survival (RFS) and progression-free survival (PFS) were estimated by log-rank tests and univariable and multivariable regression analyses.

Results: A total of 292 patients were followed, and 86% (n=251) of those included in the study were male. The median duration of TTBCG was 38.5 days (19-73). The median follow-up period was 38.4 months (21.5-72.1 months). During follow-up, recurrence was detected in 55 (18.5%) patients and progression was detected in 22 (7.5%) patients. In univariate Cox regression analysis, long TTBCG (>27.5 days) was found to have a statistically significant effect on the risk of short RFS and PFS (P=.05). BCG-related side effects were not associated with TTBCG (P=.313). Kaplan-Meier analysis showed that there was a significant difference in RFS and PFS between the TTBCG groups (P=.04, P=.011, respectively).

Conclusion: In this retrospective non-randomized study, we showed the negative effects of BCG delay on progression and recurrence in T1HG patients. Therefore, we think that BCG should be instilled within 4 weeks after surgery.