OBJECTIVEIrinotecan (CPT-11), a specific inhibitor of topoisomerase I, has been proven to be effective in the treatment of refractory or metastatic colorectal cancer. Furthermore, several first line phase III trials of the combination therapy (FOLFIRI) using CPT-11 and fuorouracil/leucovorin (5-Fu/LV) were reported to have significant improvement in treatment result. Therefore, we designed a multicenter clinical study to observe the overall survival (OS), time to death (TTD), time to progression (TTP), efficacy and safety of FOLFIRI regimen for patients with refractory or metastatic colorectal cancer after first line chemotherapy failure.

METHODSPatients with metastatic or refractory colorectal cancer after first line oxaliplatin-based chemotherapy failure were enrolled into this prospective, one arm and open-labeled multicenter study. Irinotecan 180 mg/m2 was administered biweekly on D1, LV 200 mg/m2 by intravenous infusion in 2 hours before bolus intravenous injection of 5-Fu 400 mg/m2, then followed immediately by intravenous infusion of 5-Fu 2.4 g/m2 in 46 hours. OS, TTD, TTP, response rate (RR) and adverse events were assessed according to RSCIST criteria and NCIC-CTG CTCAE (3.0).

RESULTSSixty-six patients were valuable for safety assessment and and 61 for efficacy. There was no CR patient in this series. Ten patients had PR, 35 SD (57.4% ) and 16 PD (26.2%) with a response rate of 16.4% (10/61). The median TTP was 5.0 months (1-12 months), median TTD 9.9 months (5-27 months)and median OS 18.2 months (7-33 months). The adverse events including nausea,vomiting, anorexia,diarrhea, leucopenia and cholinergic syndrome were frequent, but usually in I - II degree. The rate of III/IV degree diarrhea and leucopenia was 7.6% and 22.7%, respectively.

CONCLUSIONThe regimen of irinotecan plus fuorouracil/leucovorin (FOLFIRI) is effective and well-tolerated as a second-line chemotherapy and may prolong the overall survival for the patient with refractory or metastatic colorectal cancer.