Safety of irinotecan and infusional fluorouracil/leucovorin (FOLFIRI) in Japan: a retrospective review of 48 patients with metastatic colorectal cancer

Abstract

Background: A combination of irinotecan and infusional fluorouracil/leucovorin (FOLFIRI) has become one of the global standard chemotherapy regimens for metastatic colorectal cancer. The aim of this study was to evaluate the feasibility of FOLFIRI in a Japanese population with metastatic colorectal cancer.

Methods: This retrospective analysis included 48 patients with unresectable metastatic colorectal cancer who received FOLFIRI between May 2004 and June 2005. Evaluation points included adverse events, dose intensity, response rate, progression-free survival, and overall survival.

Results: Thirty-eight (79%) patients received FOLFIRI as first-line chemotherapy. Eighteen patients received original full-dose FOLFIRI and 30 patients received reduced FOLFIRI with irinotecan at 150 mg/m(2). Eighteen (38%) of the 48 patients experienced grade 3 or 4 neutropenia, 5 (10%) had grade 3 vomiting and 5 (10%) had grade 3 diarrhea. Toxicity was tolerable, with appropriate dose reduction if necessary. There were no treatment-related deaths or early deaths within the first 60 days of treatment. Median dose intensities (with relative dose intensities in parentheses) in all patients and in patients who received full-dose FOLFIRI were 129 mg/m(2) per 2 weeks (71%) and 144 mg/m(2) per 2 weeks (80%) for irinotecan and 2349 mg/m(2) per 2 weeks (84%) and 2376 mg/m(2) per 2 weeks (85%) for fluorouracil, respectively. The response rate in patients with measurable lesions was 37% (13/35; 95% confidence interval [CI], 21.1%-53.2%), and median progression-free survival was 8.4 months (95% CI, 6.4-10.3).

Conclusion: The dose intensity of irinotecan was relatively low, and toxicity was tolerable with appropriate dose reduction; efficacy was comparable to that previously reported. FOLFIRI is feasible and can be one of the standard treatment options for Japanese patients with metastatic colorectal cancer.