Randomized controlled trial comparing holmium laser en-bloc resection with monopolar transurethral resection in patients with large bladder tumors

ABSTRACT

Introduction & Objectives: The HoLERBT (Holmium Laser En-bloc Resection) has emerged as an alternative to classical TURBT (Transurethral Resection of Bladder Tumor) by using the en-bloc tumor resection technique. So far, the tumors in previous studies were mostly <3cm. We performed a previous pilot study with tumors >3cm (3-8cm) submitted to HoLERBT in 2019. All samples had detrusor muscle present and there were no peri-operative complications. These results support the present study to establish the best approach to endoscopic treatment of large bladder tumors. The objectives are to analyze differences between HoLERBT and TURBT in terms of presence of detrusor muscle in the histopathological analysis, intra-operative and peri-operative complications and oncological outcomes in large bladder tumors. Materials & Methods: This is a single-institution, randomized, single-blinded, prospective, controlled trial (RCT). The expected duration is of 24 months. The sample size calculated is 47 patients per group (n = 94). The study was approved by the Institutional Ethical Board and was submitted to the Brazilian Registry of Clinical Trials (ReBEC). Inclusion criteria is bladder tumor >3cm by CT or MRI. The exclusion criteria are diagnosis of invasive tumor on image examination (CT, MRI), urethral stenosis, systemic or intra-vesical chemotherapy or previous radiotherapy. The outcomes analyzed are quality of detrusor muscle, intra-operative and immediate post-operative complications, length of hospital stay (LOS);clinical progression, recurrence-free, overall and cancer-specific survival at 24 months. Results: This is an ongoing trial that began in January 2020, was suspended for 5 months due to Covid-19, restarted recruitment in September 2020 and currently has 9 patients in the group HoLERBT and 11 patients in the group TURBT. The first surgery was in 01/21/20. The current data represents 22% of the estimated sample and the analysis is partial. The median age (years) was 55.8 (29-83) and 65.5 (46-84), the median tumor size (cm) was 3.4 (2.1-5.4) and 3.1 (2.1-5.7), the median time of surgery (min) was 29 (16-49) and 37.6 (13-60), the LOS (days) was 1.25 (1-3) and 2.0 (1-4), complications rates Clavien I was 11% and 36% and Clavien >I was 0% and 9% for HoLERBT and TURBT. The presence of detrusor was 80% in both groups. The interim analysis will be made with 50% of the sample estimated to occur in June 2021 and the final analysis with 2 years of follow up is estimated to occur in January 2023. Conclusions: This is a RCT comparing HoLERBT and TURBT evolving large tumors, with a 2-year follow-up proposal. The initial analysis give support to continue the study in order to assess the real role of laser resection in high volume bladder tumor.