Long-Term Results of Bladder Preservation with Twice-Daily Radiation plus 5-Flourouracil/Cisplatin or Daily Radiation plus Gemcitabine for MIBC - Updated Report of NRG/RTOG 0712: A Randomized Phase 2 Trial.

5-FU/cisplatin and twice-daily radiation (FCT) or gemcitabine and once daily radiation (GD) are effective chemoradiation (CRT) regimens for bladder sparing treatment of muscle-invasive bladder cancer (MIBC). This trial evaluated these regimens and demonstrated efficacy with either regimen at 3 years. With further follow-up, longer term results are reported here.

Patients with cT2-4a MIBC were randomized to FCT or GD. Patients had a transurethral resection and induction CRT to 40 Gy. Patients with a complete response (CR) received consolidation CRT to 64 Gy. Others had cystectomy. Adjuvant gemcitabine/cisplatin chemotherapy was administered. The primary endpoint was freedom from distant metastasis (FDM). This updated analysis reports 7-year data. Toxicity and efficacy endpoints, including bladder intact distant metastasis free survival (BI-DMFS) were also assessed.

From 12/2008 to 4/2014, 70 patients were enrolled; 66 eligible for analysis, 33 per arm. Median follow-up was 9.1 years for eligible living patients. At 7 years, FDM was 65% and 73% for FCT and GD, respectively. BI-DMFS was 58% (95% CI: 41 - 76) and 68% (95% CI: 51-84), respectively. The post-hoc hazard ratio of 0.75 (95% CI: 0.37-1.55) showed no difference between treatments (p=0.44). Overall survival at 7 years was 48% and 59%. There were 4 and 5 cystectomies performed for FCT and GD, respectively. In the FCT arm, there were 5 (16%), 1 (3%) and 0 grade 3, 4 and 5 late toxicities reported. In the GD arm, there were 7 (23%), 0 and 0.

Both regimens maintained high FDM rates at 7 years. Cystectomy rates were low and overall survival rates high on both arms. Late toxicity rates were low. Either gemcitabine and daily radiation or a cisplatin-based regimen are effective bladder sparing therapies.

International journal of radiation oncology, biology, physics. 2024 Aug 13 [Epub ahead of print]

John J Coen, Joseph P Rodgers, Philip J Saylor, Cheryl T Lee, Chin-Lee Wu, William Parker, Tim Lautenschlaeger, Anthony L Zietman, Jason Efstathiou, Ashesh B Jani, Omer Kucuk, Luis Souhami, Stephanie L Pugh, Howard M Sandler, William U Shipley

21st Century Oncology, Providence, RI. Electronic address: ., NRG Oncology Statistics and Data Management Center - American College of Radiology, Philadelphia, PA., Massachusetts General Hospital, Boston, MA., Ohio State University Comprehensive Center, Columbus, OH., McGill University Health Centre, Montreal, QC., Indiana University, Indianapolis, IN., Massachusetts General Hospital, Harvard Medical School, Boston, MA., Emory University, Atlanta, GA., Cedars-Sinai Medical Center, Los Angeles, CA.