Two different first-line 5-fluorouracil regimens with or without oxaliplatin in patients with metastatic colorectal cancer

Background: Oxaliplatin, 5-fluorouracil (5-FU), and leucovorin (LV) are standard first-line treatments for patients with metastatic colorectal cancer (mCRC). The aim of this multicentre, open-label, phase IIIb study was to assess the addition of oxaliplatin to two different 5-FU regimens. Patients and methods: Patients with previously untreated mCRC were randomised to arm A [two-weekly oxaliplatin 85 mg/m² + either continuous intravenous infusion (CIV) of 5-FU without LV or two-weekly bolus and CIV 5-FU + LV (LV5FU2)] or arm B (5-FU CIV or LV5FU2 alone). Irinotecan monotherapy was planned on progression. Results: A total of 725 patients were enrolled. After a fixed follow-up of 2 years for each patient, 2-year survival rates were 27.3% and 24.8% in arms A and B, respectively (hazard ratio 0.93; 95% confidence interval 0.78-1.10). The addition of oxaliplatin significantly improved response rates (54.1 versus 29.8%; P < 0.0001) and median progression-free survival (7.9 versus 5.9 months; P < 0.0001). The most common grade 3-4 toxic effects were neutropenia (arm A, 33%; arm B, 5%), diarrhoea (arm A, 14%; arm B, 8%), and fatigue (arm A, 9%; arm B, 8%). Conclusions: Despite improved rates of tumour control, these results failed to demonstrate a survival benefit from the addition of oxaliplatin to infused 5-FU and lend further support to the use of sequential monotherapy in some patients with mCRC.