Patients Treated with Bladder Preserving Trimodality Chemoradiation Therapy (BPTMCRT) Off-Trial Compared to Those on Trials

e16014 Background: We assessed characteristics and outcome of patients treated with radiotherapy for muscle-invasive bladder cancer off-trial at forty-four community-based radiotherapy centers in the United States compared to those on clinical trials. Methods: We retrospectively reviewed 155 patients who had been treated from August 2010 to June 2014. Overall survival (OS) and progression free survival (PFS) were estimated using the Kaplan-Meier method. Results were compared to a pooled analysis of six RTOG protocols. Results: Characteristics were significantly inferior versus those on RTOG studies: lower rate of complete transurethral resection of bladder tumor: 36.8% versus 70.7% (p<0.0001), poorer performance status (PS): 36.8% were 0 to 1 versus 100% (p<0.0001), higher median age: 79 years versus 66 (p<0.0001), more medically inoperable: (51.0%) versus 0% in RTOG (p<0.001). Forty-seven percent had refused surgery. Fewer patients underwent concurrent chemotherapy: 56.1% versus 100% (p<0.0001). Median radiotherapy dose was similar: 64.8 Gy. At median follow-up of 12.6 months (range, 3.1-49.2), 36-month OS was 51.3% for those who refused surgery versus 24.5% for medically inoperable (p=0.009); 36-month OS was 58.1% post complete TURBT versus 29.8% if incomplete (p=0.07); 18-month PFS was 74.9% for PS 0-1 versus 36.3% for >1 (p=0.04). PS >1 patients were deceased or censored by 24 months. The 36-month OS was 54.3% with chemoradiation therapy (CRT) versus 17.2% without chemotherapy (p=0.03). Among CRT patients, the 36-month OS was 38.9% for medically inoperable versus 66.3% for those who refused surgery (p=0.04), similar to the pooled analysis of prospective RTOG protocols. Conclusions: The 66.3% 36-month OS for patients who refused surgery and received CRT suggests that it is appropriate to offer BPTMCRT to these patients in free standing centers. However, we may not be able to translate clinical trial protocols to many patients in this setting due to their poor functional reserve. More treatment options are needed for these patients given the aging population.