Irinotecan (CPT11) plus high-dose 5-fluorouracil (5-FU) and leucovorin (LV) as salvage therapy for metastatic colorectal cancer (MCRC) after failed oxaliplatin plus 5-FU and LV: a pilot study in Taiwan

Background: Irinotecan (CPT11) has established activity against advanced colorectal cancer without cross-resistance with 5-fluorouracil + leucovorin-based therapy. We conducted this pilot study to evaluate the efficacy and tolerance of combination treatment with irinotecan and 5-fluorouracil (5-FU) for patients in whom combination treatment with oxaliplatin with 5-FU + leucovorin has failed. Methods: Patients were enrolled in this study after oxaliplatin treatment had failed. The treatment protocol consisted of CPT11 (180 mg/m(2) for 90 min) on day 1 and a 2 h infusion of 200 mg/m(2) leucovorin followed by 400 mg/m2 5-FU as an intravenous bolus injection plus a 22 h continuous infusion of 600 mg/m(2) 5-FU. This regimen was repeated for two consecutive days every 2 weeks. Results: A total of 18 patients were eligible for this study and in total 144 cycles of therapy (median eight cycles) were given to these patients. Four patients (22.2%; 95% CI: 8-36.4%) achieved an objective response of partial remission (PR) and an additional seven obtained stable disease (SD) status or minor response. The median duration of response was 8 months and 14 patients were alive at the end of the study. Hematological toxicity (neutropenia) was the most common serious side effect (29.2%), followed by gastrointestinal effects (diarrhea, 28.5%). Grade II-III diarrhea was experienced for at least one cycle by each patient. Conclusions: The results of treatment for patients after oxaliplatin failure are encouraging and this treatment protocol is also well tolerated by previously heavily treated patients.