Randomized trial comparing monthly low-dose leucovorin and fluorouracil bolus with bimonthly high-dose leucovorin and fluorouracil bolus plus continuous infusion for advanced colorectal cancer: a French intergroup study.

PURPOSE: This multicenter study compared the therapeutic ratio of a monthly schedule of low-dose leucovorin (LV) and fluorouracil (5-FU) bolus with a bimonthly schedule of high-dose LV and 5-FU bolus plus continuous infusion in patients with advanced colorectal cancer. PATIENTS AND METHODS: Of the 448 patients randomly assigned to treatment, 433 were assessable. Treatment A was a monthly regimen of intravenous (IV) LV 20 mg/m2 plus bolus 5-FU 425 mg/m2 for 5 days every 4 weeks. Treatment B was a bimonthly regimen of IV LV 200 mg/m2 as a 2-hour infusion followed by bolus 5-FU 400 mg/m2 and 22-hour infusion 5-FU 600 mg/m2 for 2 consecutive days every 2 weeks. Therapy was continued until disease progression. Second-line chemotherapy, which included 5-FU continuous infusion, was allowed in both arms. RESULTS: The response rates in 348 patients with measurable lesions were 14.4% (monthly regimen) and 32.6% (bimonthly regimen) (P = .0004). The median progression-free survival times were 22 weeks (monthly regimen) and 27.6 weeks (bimonthly regimen) (P = .0012). The median survival times were 56.8 weeks (monthly regimen) and 62 weeks (bimonthly regimen) (P = .067). Grade 3-4 toxicities occurred in 23.9% of patients in the monthly arm compared with 11.1% of those in the bimonthly arm (P = .0004). Patients in arm A more frequently experienced severe granulocytopenia (7.3% v 1.9%), diarrhea (7.3% v 2.9%), and mucositis (7.3% v 1.9%) than patients in arm B. CONCLUSION: The bimonthly regimen was more effective and less toxic than the monthly regimen and definitely increased the therapeutic ratio. However, there was no evidence of increased survival.