Systematic review and meta-analysis of radiation therapy for high-risk non-muscle invasive bladder cancer.

Radiation therapy (XRT) has been investigated as a possible treatment for high-risk non-muscle invasive bladder cancer (NMIBC) with the goal of bladder preservation, especially with the ongoing Bacillus Calmette-Guerin (BCG) shortage. Yet, little is known about the clinical efficacy and the quality of evidence supporting XRT for NMIBC. Herein, we performed a systematic review and meta-analysis to evaluate XRT in the treatment of patients with high-risk NMIBC.

Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, and Web of Science were searched for high-risk NMIBC (high grade T1, T1/Ta with associated risk features: carcinoma in-situ (CIS), multifocality, > 5cm in diameter, and/or multiple recurrences) treated with primary XRT. Outcomes evaluated were recurrence-free survival (RFS), cancer-specific-survival (CSS), overall survival (OS), and salvage cystectomy and progression to metastatic disease rates. A meta-analysis was performed to assess outcomes for XRT in NMIBC.

Overall,13 studies including 746 patients met the search criteria. The 5-year rates of RFS, CSS and OS were 54% (95% CI = 38% - 70%), 86% (95% CI = 80% - 92%), and 72% (95% CI = 64% - 79%). Notably, 13% of patients proceeded to salvage radical cystectomy and 9% developed metastatic disease. All studies were of poor quality, comprising single institution and retrospective studies with only one clinical trial.

XRT for high-risk NMIBC provides some degree of oncologic control, although distant progression was noted. In the setting of the low-quality evidence, a prospective clinical trial is needed to clearly define the risks and benefits of this approach.

Urologic oncology. 2021 Apr 10 [Epub ahead of print]

Rodrigo Rodrigues Pessoa, Adam C Mueller, Peter Boxley, Thomas W Flaig, Christi Piper, Badrinath Konety, James B Yu, Boris Gershman, Janet Kukreja, Simon P Kim

University of Colorado, Division of Urology, Aurora, CO., University of Colorado, Department of Radiation Oncology, Aurora, CO., University of Colorado, Division of Medical Oncology, Aurora, CO., University of Colorado, Strauss Health Sciences Library, Aurora, CO., Rush University Medical, Division of Urology, Chicago, IL., Yale University, Department of Radiation Oncology, New Haven, CT; Yale University, Cancer Outcomes and Public Policy Effectiveness Research, (COPPER) Center, New Haven, CT., Beth Israel Deaconess Medical Center, Division of Urologic Surgery, Boston, MA., University of Colorado, Division of Urology, Aurora, CO; Yale University, Cancer Outcomes and Public Policy Effectiveness Research, (COPPER) Center, New Haven, CT. Electronic address: .