Bladder-Preserving Trimodality Treatment for High-Grade T1 Bladder Cancer: Results From Phase II Protocol NRG Oncology/RTOG 0926

Abstract

PURPOSE To investigate the use of radiation with radiosensitizing chemotherapy following repeated transurethral resection (trimodality therapy) as an alternative to radical cystectomy in T1 bladder cancer which has failed Bacillus Calmette-Guerin (BCG). PATIENTS AND METHODS Patients with recurrent T1 bladders who had failed BCG and were recommended to undergo cystectomy were treated with trimodality therapy. The primary end point was 3-year freedom from cystectomy. Secondary end points were distant metastasis at 3 and 5 years, local recurrence, disease-specific and overall survival (OS), and safety. RESULTS This single-arm phase II study enrolled 37 patients. Efficacy and safety were evaluated in 34 patients after three exclusions. The median follow-up was 5.1 years. The 3-year freedom from cystectomy rate was 88% (lower one-sided 97.5% confidence limit [CI], 72%), meeting the primary study goal. OS at 3 and 5 years was 69% (95% CI, 54 to 85) and 56% (95% CI, 39 to 74), respectively. The distant metastasis rates at 3 and 5 years were 12% (95% CI, 4 to 26) and 19% (95% CI, 7 to 34), respectively. Eight patients died due to urothelial cancer, 12 exhibited local recurrence at 3 years (cumulative incidence: 32%; 95% CI, 17 to 48), 18 experienced grade 3 adverse events, mostly hematological, and one developed grade 4 neutropenia. CONCLUSION Trimodality therapy is an effective potential alternative to radical cystectomy for recurrent high-grade T1 urothelial cancer of the bladder. At 3 years, 88% of the patients remained free of cystectomy.