A phase II study of irinotecan, 5-fluorouracil and leucovorin for treatment in patients with previously untreated advanced colorectal cancer

Purpose: We prospectively conducted a non-randomized phase II trial to evaluate the efficacy and safety of combination irinotecan, leucovorin (LV) and 5-fluorouracil (FU) as a first-line regimen for treating patients with previously untreated advanced colorectal cancer (CRC).

Materials and methods: Twenty-six previously untreated patients with advanced, recurrent or metastatic CRC were enrolled in this study. The patients received either irinotecan 180 mg/m(2) on day 1 with LV bolus of 200 mg/m(2) and FU bolus of 400 mg/m(2), and this was followed by FU continuous infusion of 600 mg/m(2) on day 1 and day 2 (the FOLFIRI regimen), or they were treated with LV bolus of 400 mg/m(2) and FU bolus of 400 mg/m(2) followed by FU continuous infusion of 2,400 mg/m(2) for 46 hours (the simplified FOLFIRI regimen), and these treatments were repeated every 2 weeks until disease progression.

Results: The objective response rate was 23.1% (6/26) respectively, for both treatments. The median time to progression was 5.3 months (range: 0.4 approximately 19.9), and the overall survival was 11.2 months (range: 0.5 approximately 52.3). The prognostic factor for longer survival was the Eastern Cooperative Oncology Group (ECOG) performance status (PS). The non-hematological toxicities were similar for both treatment groups, with more frequent grade >or=3 neutropenia being noted for the simplified FOLFIRI regimen.

Conclusion: The biweekly irinotecan based regimen was demonstrated to have a moderate antitumor activity with acceptable toxicity profiles, and the ECOG PS was the independent prognostic factor.