Combined Irinotecan, Oxaliplatin and 5-Fluorouracil in Patients with Advanced Colorectal Cancer

Abstract

Objectives: To evaluate the feasibility and a possible activity range of combination irinotecan (CPT-11), oxaliplatin, and 5-FU in advanced colorectal cancer (ACC). Patients and Methods: A total of 53 patients (51% chemoresistant) were treated. Twenty-eight received monthly intravenous oxaliplatin (120 mg/m²) and CPT-11 (250 mg/m²) on day 1 and a course of 5-FU; these constituted the IRI250 group. Twenty-five received monthly intravenous oxaliplatin (120 mg/m²), CPT-11 (300 mg/m²) on day 1, and a course of 5-FU (IRI300 group). 5-FU administration was carried out as follows. Those with predominant hepatic disease (n = 32) received an intra-arterial infusion of 5-FU (2,500 mg/day on days 1–4); these were the IA-FU group. The remaining 21 patients received intravenous 5-FU (2,600 mg/m² plus leucovorin 500 mg/m² on days 1 and 15); these constituted the IV-FUFOL group. Results: Intention-to-treat response rate was 54.7% (4 CR, 7.5%). Twelve patients (22.5%) had stable disease; only 4 (7.5%) progressed. Median progression-free and overall survivals were 10 and 18 months, respectively. One-year progression-free and overall survival rates were 44.3 and 67.4%, respectively. Grade 3–4 toxicities included diarrhea (45.3% of patients), neutropenia (52.8%), mucositis (13.2%), and emesis (11.3%). There were 3 treatment-related deaths (5.7%), all in the IA-FU/IRI300 subgroup. Severe adverse effects requiring chemotherapy dose adjustment were observed in 67.9% of the patients, with odds ratios 9.04-fold higher in the IA-FU/IRI300 group (95% CI: 1.07–76.20) and 0.23-fold lower in the IV-FUFOL/IRI250 group (95% CI: 0.05–0.97). Conclusion: This combination seems to have substantial activity in ACC. Overall toxicity was unacceptable in the IA-FU and IRI300 groups, with diarrhea and cytopenia constituting the dose-limiting side effects. Tolerance and efficacy profiles achieved with IV oxaliplatin (120 mg/m² day 1), IV CPT-11 (250 mg/m² day 1) and IV 5-FU 2.6 g/m² with IV leucovorin (500 mg/m² days 1 and 15) was favorable and deserves further investigation.