[Irinotecan monotherapy in the treatment of colorectal cancers: results of phase II trials].

Irinotecan or CPT11 is a topoisomerase 1 inhibitor. The European and American regimens of irinotecan in monotherapy are different: respectively 350 mg/m2 i.v. every 3 weeks and 125 mg/m2 i.v. weekly (4 weeks out of 6). In a large phase 2 programme an important activity has been shown in metastatic colorectal cancer. In 5FU resistant colorectal cancer an objective response rate of 13% has been shown. This was associated with a long median time of response, a long median time to progression and a long median survival. More than 40% of patients had also a stabilisation in second line treatment. This interesting activity was the basis for the phase 3 studies that have positioned irinotecan as the standard treatment in 5FU resistant colorectal cancer. The response rate in first line treatment of colorectal cancer varies between 18% and 32%. The main side effects are neutropenia and delayed diarrhea.