Oxaliplatin combined with weekly bolus fluorouracil and leucovorin as surgical adjuvant chemotherapy for stage II and III colon cancer: Results from NSABP C-07

Purpose: This phase III clinical trial evaluated the impact on disease-free survival (DFS) of adding oxaliplatin to bolus weekly fluorouracil (FU) combined with leucovorin as surgical adjuvant therapy for stage II and III colon cancer. Patients and Methods: Patients who had undergone a potentially curative resection were randomly assigned to either FU 500 mg/m² intravenous (IV) bolus weekly for 6 weeks plus leucovorin 500 mg/m² IV weekly for 6 weeks during each 8-week cycle for three cycles (FULV), or the same FULV regimen with oxaliplatin 85 mg/m² IV administered on weeks 1, 3, and 5 of each 8-week cycle for three cycles (FLOX). Results: A total of 2,407 patients (96.6%) of the 2,492 patients randomly assigned were eligible. Median follow-up for patients still alive is 42.5 months. The hazard ratio (FLOX v FULV) is 0.80 (95% Cl, 0.69 to 0.93), a 20% risk reduction in favor of FLOX (P < .004). The 3- and 4-year disease-free survival (DFS) rates were 71.8% and 67.0% for FULV and 76.1% and 73.2% for FLOX, respectively. Grade 3 neurosensory toxicity was noted in 8.2% of patients receiving FLOX and in 0.7% of those receiving FULV (P < .001). Hospitalization for diarrhea associated with bowel wall thickening occurred in 5.5% of the patients receiving FLOX and in 3.0% of the patients receiving FULV(P < .01). A total of 1.2% of patients died as a result of any cause within 60 days of receiving chemotherapy, with no significant difference between regimens. Conclusion: The addition of oxaliplatin to weekly FULV significantly improved DFS in patients with stage II and III colon cancer. FLOX can be recommended as an effective option in clinical practice.