Holmium Laser En-bloc Resection Versus Conventional Transurethral Resection of Bladder Tumors for Treatment of Non-muscle-invasive Bladder Cancer: A Randomized Clinical Trial

Abstract

Background: En-bloc resection of bladder tumors achieves complete tumor removal, improves the quality of resection, decreases perioperative complication, and potentially improves recurrence rates.

Objective: To assess the efficacy and safety of holmium laser en-bloc resection (HolERBT) versus conventional transurethral resection of bladder tumor (cTURBT).

Design, setting, and participants: Between September 2015 and September 2018, 100 patients with non-muscle-invasive bladder cancer were randomly allocated to cTURBT or HolERBT.

Outcome measurements and statistical analysis: The primary endpoint was detection of residual tumor in reTURBT specimens at 4 wk after the primary resection. Operative parameters, specimen quality, perioperative complications, and recurrence-free survival (RFS) were compared. Independent sample t tests, χ² tests, and Kaplan-Meier curves were used, as appropriate.

Results and limitations: The patient and tumor baseline characteristics were comparable between the groups. Residual tumors were detected in 7% and 27.7% of cases after HolERBT and cTURBT, respectively (p=0.01). Detrusor muscle was sampled in 98% of HolERBT and 62% of cTURBT cases (p<0.001). Lamina propria invasion substaging was feasible in only 68.2% of HolERBT and 18.4% of cTURBT cases (p<0.001). Following HolERBT, catheterization time (p<0.001) and hospital stay (p=0.001) were shorter when compared to cTURBT. Immediate postoperative instillation of chemotherapy in indicated cases was feasible for 100% of the HolERBT group and 91.5% of the cTURBT group (p=0.04). After follow-up of 20 ± 9.9 mo (13-36), RFS was 31.76 mo (95% confidence interval [CI] 28.67-34.86) in the HolERBT group and 28.25 mo (95% CI 24.87-31.64) in the cTURBT group (hazard ratio 0.43, 95% CI 0.17-1.1; p=0.07). However, this study was not powered to detect a difference in RFS.

Conclusions: Compared to cTURBT, HolERBT is a safer procedure for bladder tumor resection. It fulfills the oncological criteria of optimized resection with less residual tumor and better specimen quality.

Patient summary: En-bloc resection of bladder cancer tumors using a holmium laser is safer than the conventional technique. It has the advantages of less residual tumor and better specimen quality, with a similar tumor recurrence rate. This study is registered at ClinicalTrials.gov as NCT02555163.

Keywords: Bladder tumor; Laser; Non–muscle-invasive bladder cancer; Resection; Transurethral resection of bladder tumor.