Phase II trial finds adding gemcitabine to cisplatin-radiotherapy does not improve 2-year disease-free survival in muscle-invasive bladder cancerAdding gemcitabine to cisplatin did not improve disease-free survival in bladder cancer patients

INTRODUCTION: Trimodal therapy (TMT) is a viable option for muscle-invasive bladder cancer (MIBC), but the optimal chemotherapy regimen remains unclear. This phase II randomized trial (NCT01495676) compared cisplatin (CDDP) with twice-weekly gemcitabine (GEM) and radiation therapy (RT) with CDDP plus RT. METHODS: Patients with pT2-pT3N0M0 MIBC, after macroscopically complete transurethral resection (TURBT), received RT (63 Gy to the bladder, 45 Gy to the pelvis, 1,8 Gy/ fraction) with chemotherapy (CDDP 20 mg/m/day for 4 days every 21 days alone or plus GEM 25 mg/m twice weekly). The primary endpoint was 2-year disease-free survival (DFS); secondary endpoints included overall survival (OS) and toxicities. A 1:2 randomization was planned to include 36 patients in the control arm and 73 patients in the experimental arm. RESULTS: Sixty-nine patients were included: 24 in the RT/CDDP arm and 45 in the RT/CDDP/GEM arm. The median follow-up was 63 months. Two-year DFS was similar between groups (58.3% CI95% [36.6-77.9] vs. 60.0% CI95% [44.3-74.3]), with median DFS of 29.8 (RT/CDDP) vs. 37.4 (RT/CDDP/GEM) months. OS at 24 and 60 months was 91.3% [IC 95% 69.5-97.8] and 66.8% [IC 95% 39.6-83.9] (RT/CDDP) vs. 66.7% % [IC 95% 50.2 - 78.8] and 53.7% [IC 95% 37.2 - 67.6] (RT/CDDP/GEM). Toxicity profiles were comparable except for increased cytopenias in the GEM arm. CONCLUSIONS: Adding GEM to CDDP did not improve 2-year DFS in MIBC patients treated with TMT. Results should be interpreted cautiously due to early study termination and insufficient accrual.