A phase II study of irinotecan alternated with a weekly schedule of oxaliplatin, high-dose leucovorin and 48-hour infusion 5-fluorouracil in patients with advanced colorectal cancer.

ABSTRACT

OBJECTIVES: To evaluate the safety and efficacy of irinotecan (CPT-11) alternated with a weekly treatment for 4 weeks of oxaliplatin (L-OHP), high-dose leucovorin (LV) and a 48-hour 5-fluorouracil infusion (5-FU 48 h) as first-line chemotherapy for patients with advanced colorectal cancer (ACC). PATIENTS AND METHODS: Previously untreated patients with ACC received chemotherapy consisting of a weekly treatment for 4 weeks of L-OHP (65 mg/m2), high-dose LV (150 mg/m2) followed by a 5-FU 48 h infusion (2,300 or 1,800 mg/m2) alternated with CPT-11 (350 mg/m2). A cycle was to be performed every 8 weeks. Treatment was continued up to tolerance, disease progression or patient refusal. Forty consecutive patients with measurable ACC, aged 26-70, performance status < or =2, entered our study. RESULTS: Six complete and 17 partial responses were observed (overall response rate, 57.5%; 95% confidence interval, CI 38.8-71.1%); an additional 35% of the patients had stable disease. The median duration of response was 10.9 months (range, 6.5-30+ months). The median time to progression and the median overall survival time were 11.4 (95% CI 10.4-12.3) and 20.3 (95% CI 16.4-23.7) months, respectively. At the median follow-up period of 24 months, 17 patients (42.5%) are still alive. After a median number of 4 cycles, one toxic death occurred. The incidence of grade 3-4 toxicity per patient in any cycle was stomatitis 7.5%, nausea/vomiting 2.5% and diarrhea 45% for the infusional part, neutropenia 37.5%, anemia 2.5%, thrombocytopenia 5%, alopecia 5% and diarrhea 10% for the CPT-11 part of the regimen. Gastrointestinal toxicity was different according to the dose of 5-FU. Serious adverse events occurred most frequently when 5-FU was given at a dose of 2,300 mg/m2 with a high incidence of grade 3-4 diarrhea (72.2%) and stomatitis (16.6%), and led to dose reduction of 5-FU in 13 of 18 patients (72.2%). For 22 patients who started 5-FU at a dose of 1,800 mg/m2, a dose reduction of 5-FU was necessary only 5 times (22.7%). No patient discontinued treatment because of severe neurotoxicity. CONCLUSIONS: The activity of our alternating regimen of L-OHP/LV/5-FU 48 h and CPT-11 for not previously treated ACC patients is counterbalanced by a high toxicity and a inconvenient schedule.