Neoadjuvant Modified FOLFOX6 With or Without Radiation Versus Fluorouracil Plus Radiation for Locally Advanced Rectal Cancer: Final Results of the Chinese FOWARC Trial.

PURPOSE: In the multicenter, open-label, phase III FOWARC trial, modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus radiotherapy resulted in a higher pathologic complete response rate than fluorouracil plus radiotherapy in Chinese patients with locally advanced rectal cancer. Here, we report the final results. METHODS: Adults ages 18 to 75 years with stage II/III rectal cancer were randomly assigned (1:1:1) to five cycles of infusional fluorouracil (leucovorin 400 mg/m2, fluorouracil 400 mg/m2, and fluorouracil 2.4 g/m2 over 48 hours) plus radiotherapy (46.0 to 50.4 Gy delivered in 23 to 25 fractions during cycles 2 to 4) followed by surgery and seven cycles of infusional fluorouracil, the same treatment plus intravenous oxaliplatin 85 mg/m2 on day 1 of each cycle (mFOLFOX6), or four to six cycles of mFOLFOX6 followed by surgery and six to eight cycles of mFOLFOX6. The primary end point was 3-year disease-free survival (DFS). RESULTS: In total, 495 patients were randomly assigned to treatment. After a median follow-up of 45.2 months, DFS events were reported in 46, 39, and 46 patients in the fluorouracil plus radiotherapy, mFOLFOX6 plus radiotherapy, and mFOLFOX6 arms. In each arm, the probability of 3-year DFS was 72.9%, 77.2%, and 73.5% (P = .709 by the log-rank test), the 3-year probability of local recurrence after R0/1 resection was 8.0%, 7.0%, and 8.3% (P = .873 by the log-rank test), and the 3-year overall survival rate was 91.3%, 89.1%, and 90.7% (P = .971 by log-rank test), respectively. CONCLUSION: mFOLFOX6, with or without radiation, did not significantly improve 3-year DFS versus fluorouracil with radiation in patients with locally advanced rectal cancer. No significant difference in outcomes was found between mFOLFOX6 without radiotherapy and fluorouracil with radiotherapy, which requires additional investigation of the role of radiotherapy in these regimens.

Modified FOLFOX6 With or Without Radiation Versus Fluorouracil and Leucovorin With Radiation in Neoadjuvant Treatment of Locally Advanced Rectal Cancer: Initial Results of the Chinese FOWARC Multicenter, Open-Label, Randomized Three-Arm Phase III Trial.

PURPOSE: Total mesorectal excision with fluorouracil-based preoperative chemoradiotherapy and postoperative chemotherapy is a standard treatment of locally advanced rectal cancer. This study investigated the addition of oxaliplatin with and without preoperative radiotherapy. METHODS: In this multicenter, open-label, phase III trial, we randomly assigned (1:1:1) Chinese adults (age 18 to 75 years) with locally advanced stage II/III rectal cancer to three treatments: five 2-week cycles of infusional fluorouracil (leucovorin 400 mg/m(2), fluorouracil 400 mg/m(2), and fluorouracil 2.4 g/m(2) over 48 h) plus radiotherapy (46.0 to 50.4 Gy delivered in 23 to 25 fractions during cycles 2 through 4) followed by surgery and seven cycles of infusional fluorouracil, the same treatment plus intravenous oxaliplatin 85 mg/m(2) on day 1 of each cycle (modified FOLFOX6 [mFOLFOX6]), or four to six cycles of mFOLFOX6 followed by surgery and six to eight cycles of mFOLFOX6. Random assignment was performed by using computer-generated block randomization codes. The primary end point was 3-year disease-free survival. Secondary end points of histopathologic response and toxicity are reported. RESULTS: A total of 495 patients were enrolled from June 2010 to February 2015; 475 were evaluable (fluorouracil-radiotherapy, n = 155; mFOLFOX6-radiotherapy, n = 157; mFOLFOX6, n = 163). In the fluorouracil-radiotherapy, mFOLFOX6-radiotherapy, and mFOLFOX6 groups, the rate of pathologic complete response (pCR) was 14.0%, 27.5%, and 6.6%, and downstaging (ypStage 0 to 1) was achieved by 37.1%, 56.4%, and 35.5% of patients, respectively. Higher toxicity and more postoperative complications were observed in patients who received radiotherapy. CONCLUSION: mFOLFOX6-based preoperative chemoradiotherapy results in a higher pCR rate than fluorouracil-based treatment. Perioperative mFOLFOX6 alone had inferior results and a lower pCR rate than chemoradiotherapy but led to a similar downstaging rate as fluorouracil-radiotherapy, with less toxicity and fewer postoperative complications.