Three-year outcomes of GCR-3: A phase II randomized trial comparing conventional preoperative chemoradiation (CRT) followed by surgery and postoperative adjuvant chemotherapy (CT) with induction CT followed by CRT and surgery in locally advanced rectal cancer.

Abstract

3552 Background: Compared with postoperative adjuvant Capecitabine/Oxaliplatin (CAPOX), induction chemotherapy before to CRT had similar pCR rates, but did achieve more favourable compliance and toxicity profiles as we previously have published. (J Clin Oncol 28:859-865, 2010). We now report on the 3-year outcomes of this randomized trial. Methods: Patients with locally advanced rectal cancer and stratified by institution, were randomly assigned to arm A—preoperative CRT with capecitabine, oxaliplatin, and concurrent radiation followed by surgery and four cycles of postoperative adjuvant CAPOX—or arm B—induction CAPOX followed by CRT and surgery. The following three-year outcomes were assessed: the cumulative incidence of local-regional (LRF) and distance failure (DF), disease-free (DFS) and overall (OS) using the Kaplan-Meier method. Results: Of 108 patients accrued, 103 were analyzable for outcomes. With a median follow-up time of 39.3 months (0.1-53), the 36 DFS rates were 68% (95% CI, 53% to 80%) for arm A and 70% (95% CI, 55% to 80%) in arm B. (p=0.97). The 36-month overall survival rates were 90% (95% CI, 77% to 96%) and 81%(95% CI, 68%to 89%) for arms A and B, respectively (p= 0.18). 11 patients experienced relapse in arm A (1 local, 10 distant),and 12 experienced relapse in arm B (2 local, and 10 distant). p = 0.6036. Conclusions: Although not powered to draw any comparative conclusions, induction CT prior to CRT and surgery for the treatment of locally advanced rectal cancer yields similar three-year outcomes as standard strategy. Because of the associated acute toxicity sparing and better compliance, a larger trial is warranted with this strategy.