SAN FRANCISCO, CA USA (UroToday.com) - Complete Title: GU Cancers Symposium 2014 - The initial report of RTOG 0524: Phase I/II trial of a combination of paclitaxel and trastuzumab with daily irradiation or paclitaxel alone with daily irradiation following transurethral surgery for noncystectomy candidates with muscle-invasive bladder cancer - Session Highlights
Dr. M. Dror Michaelson and colleagues reported on the RTOG 0524 trial, looking at the safety and efficacy of trimodality, organ-preserving therapy in patients with UC overexpress HER2/neu, who were not suitable for radical cystectomy. Patients with invasive bladder UC (stages T2-T4a, N0-1, M0) who underwent cystoscopic tumor resection were analyzed by HER2/neu immunohistochemistry (IHC) and assigned to chemotherapy groups I (IHC 2+ or 3+; paclitaxel and trastuzumab) or II (IHC negative or 1+; paclitaxel alone). Concurrent weekly paclitaxel (50 mg/m2), weekly trastuzumab (group I only) and daily radiation (64.8 Gy total in 36 fractions) were also given for seven consecutive weeks. The primary endpoint of the study was acute protocol-defined toxicity related to treatment.
Twenty-one eligible patients were included in group I and 47 in group 2. Median ages were 80 and 73, respectively. Acute toxicity was observed in 7/21 patients (33%) in group I and 14/47 patients (30%) in group II. Most common grade > 3 adverse events in groups I and II were marrow suppression (43% and 17%), diarrhea (33% and 30%), and hyponatremia (14% and 4%). Three deaths on study were attributed to colonic perforation, pneumonia, and sudden death. Radiation completion rates were 72% and 85% in the two groups, and full-dose chemotherapy completion rates were 52% and 51%. Evaluation by cystoscopy and/or tumor biopsy at 12 weeks noted complete response in 9/13 patients (69%) in group I, in 19/33 patients (58%) in group II, and was not performed in the remaining patients.
They concluded that although the response rate for HER2/neu-targeted therapy is acceptable, it may also increase certain adverse events in this challenging population. Also, they show that trimodality bladder-preserving therapy can be an appropriate treatment in patient with invasive UC who do not have adequate cardiopulmonary reserve to undergo radical cystectomy.
Highlights of a presentation by M. Dror Michaelson, MD, PhD at the 2014 Genitourinary Cancers Symposium - January 30 - February 1, 2014 - San Francisco Marriott Marquis - San Francisco, California USA
Massachusetts General Hospital, Boston, MA USA