Is a second TUR necessary in patients with primary high-grade Ta NMIBC, particularly in the context of initial cases?

Objective: To evaluate the clinical significance of a second transurethral resection of the bladder tumour (TURBT) in patients with a primary high-grade (HG) Ta non-muscle invasive bladder cancer (NMIBC), specifically selected for the initial diagnosis. Patients and Methods: We retrospectively analysed 121 patients with primary HG Ta urothelial carcinoma treated at our institution between January 2007 and October 2024. All patients underwent an initial TURBT with the detrusor muscle present in the specimen. Patients were divided into the second TUR group (n = 48) and the non-second TUR group (n = 73). Propensity score matching was performed using age, number of tumours and Bacillus Calmette-Guerin treatment status. Outcomes included the residual tumour rate, recurrence-free survival (RFS), time to progression to muscle invasive bladder cancer (MIBC) and cancer-specific survival (CSS). Results: Residual tumour at the initial resection site was identified in four patients (8.3%) who underwent a second TUR, with two patients (4.2%) being upstaged to T1. The median follow-up was 53 months. There were no significant differences between the two groups in RFS (p = 0.60), time to progression to MIBC (p = 0.63) or CSS (p = 0.18). These findings remained consistent in the matched cohort. Multivariate analysis revealed that a second TUR was not associated with improved RFS. Conclusions: This is the first study to specifically address primary HG Ta bladder cancer, and it suggests that a second TUR may be omitted in selected cases, particularly when the initial resection is complete and the detrusor muscle is adequately sampled. A risk-adapted approach may help reduce unnecessary procedures without compromising oncological safety.