Evaluation of thulium laser endoscopic en bloc resection versus conventional trans-urethral en bloc resection of primary non-muscle invasive bladder cancer: a randomized controlled trial.

PURPOSE: To compare thulium laser endoscopic en bloc resection (TmLRBT) with bipolar transurethral en bloc resection (bERBT) for primary non-muscle-invasive bladder cancer. METHODS: In this multicenter, parallel-group randomized controlled trial, adults with primary urothelial tumors <3 cm and no clinical muscle invasion or metastasis were allocated 1:1 to TmLRBT or bERBT. The primary outcome was 12-month recurrence-free survival, assessed as recurrence-free status at 12 months and supported by time from index surgery to first documented bladder tumor recurrence or censoring within 12 months. RESULTS: Of the 69 patients assessed, 56 were randomized; 50 completed 12-month follow-up and were included in the complete case analysis. TmLRBT improved mean recurrence-free survival (11.6 ± 1.3 vs 10.0 ± 3.1 months; MD +1.60; 95% CI +0.23 to +2.97; p=0.023). Twelve-month recurrence was significantly lower after TmLRBT than bERBT (4/25 [16.0%] vs 12/25 [48.0%]; RR 0.33, 95% CI 0.12-0.89; p=0.032). TmLRBT prolonged surgery but reduced catheterization, hospitalization, irrigation, and obturator reflex, with no intraoperative bleeding, moderate postoperative bleeding, perforation, postoperative complications, or procedure-related deaths. CONCLUSION: TmLRBT was associated with improved 12-month recurrence outcomes, longer mean recurrence-free survival, and favorable perioperative safety compared with bERBT. TRIAL REGISTRATION: ClinicalTrials.gov, NCT06818799, retrospectively registered February 10, 2025.