The combination of capecitabine and irinotecan in treating 5-Fluorouracil- and Oxaliplatin-pretreated metastatic colorectal cancer

Purpose: Since the combination of capecitabine and irinotecan has successfully been used as a first-line treatment in metastatic colorectal cancer (MCRC), we expected promising results when given as a second-line treatment to metastatic colorectal patients who had been pretreated with 5-Fluorouracil and Oxaliplatin. Methods: Thirty-three MCRC patients participated in this study and received an oral dose of 1,000 mg/m² capecitabine twice daily on days 1-14 and a dose of 100 mg/m² irinotecan infused over 90 min on days 1 and 8, every 3 weeks. Results: The overall response rate in intent-to-treat was 33.3% (95% CI, 21.5-58.3%), including one complete response (3.0%) and ten partial responses (30.3%); 12 patients (36.4%) had disease stabilization and only 9 (27.3%) progressed. The median time to progression was 6.7 months (95% CI, 4.8-8.6 months). After a median follow-up time of 12 months, nine patients (27.3%) were still alive with metastatic disease. The median response duration for all patients was 6.7 months (95% CI, 3.9-9.5 months) and the median overall survival was 13.4 months (95% CI, 11.0-15.8 months) with a 1-year survival rate of 55.4%. Myelosuppression was commonly observed; NCI-CTC (v 2.0) grade 3/4 neutropenia, however, occurred in eight (24%) patients and grade 3 anemia was seen in one patient (3%). The most common (grade 3/4) non-hematological toxicity was diarrhea (15%) and the other severe grade 3/4 toxicities included nausea/vomiting in one patient (3%), stomatitis in one patient (3%), hand-foot syndrome in one patient (3%). Conclusions: The combination of capecitabine and irinotecan is an effective and well-tolerated regimen for second-line treatment of metastatic colorectal cancer. However, further phase III trials are required to clarify its use in the treatment of metastastic colorectal cancer patients who have been pretreated with 5-fluorouracil and oxaliplatin.