Patients with curatively resected rectal cancer are more likely to be disease-free at 3 years after treatment with an oxaliplatin-containing regimen than with fluorouracil (5-FU)/leucovorin, Korean investigators of the phase II multicenter ADORE trial reported at the ASCO Annual Meeting.1
Study Details
“The ADORE study demonstrated that adjuvant FOLFOX [5-FU/leucovorin/oxaliplatin] improves 3-year disease-free survival compared with 5-FU/leucovorin in patients with pathologic stage II or III rectal cancer after fluoropyrimidine-based preoperative chemoradiotherapy,” said Tae Won Kim, MD, of Asan Medical Center at the University of Ulsan College of Medicine, South Korea.
The study included 321 patients who underwent preoperative chemoradiotherapy and total mesorectal excision with curative intent. Only those with postoperative stage II or III were selected for this study. The study aimed to evaluate the benefit of adding oxaliplatin to fluoropyrimidine-based adjuvant therapy after this standard approach.
The phase II study randomly assigned 321 patients to adjuvant FOLFOX every 2 weeks for eight cycles or 5-FU/leucovorin every 4 weeks for four cycles. Patients received conventional preoperative radiotherapy (median dose, 50 Gy; median duration, 5 weeks) and concurrent chemotherapy with 5-FU or capecitabine. The median follow-up was 38 months.
Improved Disease-Free Survival
Disease-free survival events occurred in 39 patients receiving adjuvant FOLFOX and 53 receiving 5-FU/leucovorin, amounting to 3-year disease-free survival rates of 71.6% and 62.9%, respectively (stratified hazard ratio [HR] = 0.630, P = .032).
The difference was seen only in patients with postneoadjuvant pathologic (yp) stage III disease , and not in patients with yp stage II disease, he added. Among patients with yp stage II rectal cancer, disease-free survival was 81.6% with FOLFOX and 71.3% with 5-FU/leucovorin (HR = 0.744, P = .469).
“Adjuvant FOLFOX remained as a significant factor affecting 3-year disease-free survival after stratified Cox regression analysis,” Dr. Kim reported.
FOLFOX was associated with more neutropenia and thrombocytopenia of all grades and more fatigue and nausea, but there were no differences in grade 3/4 nonhematologic or hematologic adverse events. ■
Disclosure: The authors reported no potential conflicts of interest.
Reference
1. Hong YS, Nam B, Kim K, et al: Adjuvant chemotherapy with oxaliplatin/5-fluorouracil/leucovorin (FOLFOX) versus 5-fluorouracil/leucovorin for rectal cancer patients whose postoperative yp stage 2 or 3 after preoperative chemotherapy: Updated results of 3-year disease-free survival from a randomized phase II study (The ADORE). ASCO Annual Meeting. Abstract 3502. Presented June 2, 2014.
