[Effect of chemotherapy using irinotecan (CPT-11) against recurrent colorectal cancer]

Irinotecan (CPT-11) is a camptothecine derivative with antitumor activity and inhibitor of DNA topoisomerase I. CPT-11 showed a excellent and broad anticancer activity against several malignant tumors. In this study, as in the Japanese phase II study, CPT-11 was administered at 100 mg/m2 weekly by intravenous infusion against 10 patients with recurrent colorectal cancer. Median total dose was 513 mg. Partial responses were obtained in 4/10 patient (40%). Lung metastases showed a 33.3% response and lymphnode metastases showed a 60% response. However, liver metastases showed no response. The median duration to the onset of partial response was 20 days and the median overall response duration was 89 days. Adverse effects were leukopenia (40%), nausea, vomiting and diarrhea (80%), fever (20%), and general malaise (30%). These were generally well tolerated and reversible. From these results, CPT-11 seemed to become an effective drug for recurrent colorectal cancer. Further trials of combination chemotherapy utilizing CPT-11 seem to be warranted.