Purpose: A combination of irinotecan with continuous infusional 5-fluorouracil (5-FU) is the standard treatment for advanced colorectal cancer. The aim of this study was to determine the efficacy and safety of combining irinotecan and S-1 (IRIS) in patients with advanced colorectal cancer.
Methods: Irinotecan was administered as an intravenous infusion at a dose of 120 mg/m(2) on day 1 and 15. And S-1 was administered orally on days 1-14 of a 28-day cycle. S-1 was given orally at a dose that did not exceed 40 mg/m(2) based BSA: BSA < 1.25 m(2), 40 mg twice daily; 1.25-1.5 m(2), 50 mg twice daily, and BSA > 1.5 m(2), 60 mg twice daily, for 14 consecutive days.
Results: A total of 38 patients were enrolled. An intent-to-treat analysis showed a complete response and partial response to occur in 13.2% and 50.0%, respectively. The disease control rate was 84.2%. The median progression-free survival and overall survival were 10.0 months and 29.1 months, respectively. The rates of grade 3/4 toxicity over 4 cycles were the following: neutropenia, 15.8%; leucopenia, 7.9%; anorexia, 15.8%; diarrhea, 10.5%.
Conclusion: IRIS is an effective, well tolerated and convenient treatment regimen for patients with advanced colorectal cancer.