Green-light laser en bloc resection versus conventional transurethral resection for initial non-muscle-invasive bladder cancer: A randomized controlled trial

Objective: To compare the safety and outcomes between green-light laser en bloc resection and transurethral resection of bladder tumor. Methods: A single-center, randomized controlled trial was carried out from August 2014 to September 2018. Patients with initial non-muscle-invasive bladder cancer were randomized to green-light laser en bloc resection or transurethral resection of bladder tumor. The primary outcomes were pathological findings and perioperative events. The secondary outcome was tumor recurrence. Results: A total of 233 patients were randomized to the transurethral resection of bladder tumor group (117 patients) and the green-light laser en bloc resection group (116 patients). The resection time was longer in the green-light laser en bloc resection group (P = 0.022); however, no differences were identified in overall operative time (P = 0.255). Nine patients (7.7%) had an obturator nerve reflex during transurethral resection of bladder tumor. The estimated volume of blood loss was significantly lower in the green-light laser en bloc resection group (P = 0.012). The green-light laser en bloc resection group had a higher rate of T1 bladder cancer (P = 0.031). A total of 104 patients (89.7%) treated with green-light laser en bloc resection had detrusor muscle presence in the specimen, whereas 37 (31.9%) patients had the presence of muscularis mucosae, which was significantly higher than the corresponding number of transurethral resection of bladder tumor patients (P = 0.005 and 0.002, respectively). After a median follow-up period of 48 months, just five patients had tumor recurrence (three in the transurethral resection of bladder tumor group and two in the green-light laser en bloc resection group), and there was no difference between these two groups. Conclusions: Compared with transurethral resection of bladder tumor, green-light laser en bloc resection is more effective due to less obturator nerve reflex and the same recurrence rate. Most importantly, green-light laser en bloc resection can provide better tumor specimens for pathological examinations.