Modified irinotecan plus bolus 5-fluorouracil/L-leucovorin for metastatic colorectal cancer at a single institution in Japan.

BACKGROUND: The modified irinotecan plus bolus 5-fluorouracil/L-leucovorin (IFL) regimen (irinotecan plus bolus 5-fluorouracil/L-leucovorin) used to be one of the standard treatments for metastatic colorectal cancer until approval of oxaliplatin in Japan. We evaluated the efficacy of modified IFL therapy for Japanese patients.

METHODS: Forty-seven patients with metastatic colorectal cancer received irinotecan (100 mg/m(2)) and bolus 5-fluorouracil (500 mg/m(2)) plus L-leucovorin (10 mg/m(2)) on days 1 and 8 every 3 weeks until progression or unmanageable toxicity occurred. The data on toxicity and tumor response were analyzed retrospectively.

RESULTS: All patients discontinued modified IFL therapy due to cancer progression, except for one patient who developed severe liver dysfunction. The overall response rate was 25%. The median progression-free survival time (PFS) was 8.6 [corrected] months. The median overall survival time (OS) was 27.8 [corrected] months for all patients, 30.9 [corrected] months for patients receiving subsequent oxaliplatin therapy, and 14.5 [corrected] months for patients without oxaliplatin (P = 0.0031). According to multivariate analysis results, good performance status, a normal white cell count, and absence of local recurrence were associated with a better PFS. Tumor response was a good prognostic factor for both PFS and OS. Gastrointestinal symptoms were the most common toxicities, including grade 3 diarrhea (8%) and grade 3 anorexia (10%). Grade 4 neutropenia occurred in 6% of patients. No other drug-related severe adverse events or deaths were observed.

CONCLUSIONS: Modified IFL therapy is an effective and well-tolerated regimen for Japanese patients with metastatic colorectal cancer. Modified IFL therapy combined with biological agents might remain an option for some patients who refuse a central venous catheter.