Preoperative Chemoradiotherapy and Postoperative Chemotherapy in Locally Advanced Rectal Cancer—Results of the CAO/ARO/AIO-04 Trial

Conference Correspondent - ASCO 2014 - Colorectal and Head & Neck Cancer

A previous clinical study established preoperative chemoradiotherapy, total mesorectal excision (TME) surgery, and adjuvant chemotherapy with 5-fluorouracil (5-FU) as the standard treatment for locally advanced rectal cancer (LA-RC). The CAO/ARO/AIO-04 trial for which the results were reported at ASCO 2014 attempted to determine the most effective adjuvant chemotherapy protocol for these patients (Rodel C, et al. ASCO 2014. Abstract 3500). A total of 637 patients with cT3/4 or cN+ rectal cancer were randomized into 2 treatment arms: Arm A = preoperative 50.4 Gy plus 5-FU, followed by TME, and 4 cycles of adjuvant 5-FU, or Arm B = preoperative 50.5 Gy plus 5-FU plus oxaliplatin, followed by TME, and 8 cycles of adjuvant oxaliplatin, leucovorin, and 5-FU. The primary endpoint was disease-free survival (DFS) at 3 years. At a median follow-up of 50 months, the 3-year DFS was 71.2% in Arm A and 75.9% in Arm B (P = .03). Grade 3 or 4 adverse events occurred in 23% of patients in Arm A and 26% in Arm B (P = .14). These data suggest that adding oxaliplatin to 5-FU as adjuvant therapy significantly improves DFS in patients with LA-RC. “It has been estimated that the additional cost of oxaliplatin when combined with 5-FU/leucovorin is approximately $6000 per QALY [quality-adjusted life-year] gained, making the regimen outlined in Arm B a cost-effective treatment to extend DFS in these patients.”