Topotecan in colorectal cancer: a phase II study of the EORTC early clinical trials group.

PURPOSE This phase II study with the topoisomerase I inhibitor topotecan was performed to determine its clinical activity and toxicity in patients with metastatic or locally unresectable colorectal cancer. PATIENTS AND METHODS Topotecan 1.5 mg/m2 was administered intravenously by 30-minute infusion for 5 days. Fifty-nine patients entered the study, 2 were considered ineligible and 57 were evaluable for response and toxicity. RESULTS Partial response was obtained in 4 of 57 evaluable patients (7%). The median duration of the response was 11 months (range 9.3 to 12.2). This topotecan regimen was very well tolerated. A total of 290 courses were given, with a median of 4 courses per patient (range, 1 to 18). The major toxic effects were leuko- and neutropenia (91%), grade 3-4 in 48% and 79% of courses, respectively, but with only 2 infectious complications. Other side effects were grade 1 alopecia (77%) in 46%, nausea (35%), vomiting (10%), and maculo-papular rash (6%). CONCLUSIONS Topotecan administered as a daily-times-five regimen has only minor activity as a single-agent therapy in colorectal cancer.