Irinotecan-Based Regimens in the Adjuvant Therapy of Colorectal Cancer

Irinotecan is a cornerstone drug in the management of metastatic colorectal cancer, as demonstrated by several randomized studies proving a survival benefit for the first time. In the adjuvant setting, FOLFOX (infusional 5-fluorouracil [5-FU]/leucovorin [LV] in combination with oxaliplatin) has improved 3-year disease-free survival in stage II/III colorectal cancer in the MOSAIC trial. Because 5-FU/LV-based combination therapy with oxaliplatin or irinotecan has similar efficacy in metastatic disease in the first-line setting, the impact of irinotecan in the adjuvant setting deserves further randomized clinical trials. Six such trials are ongoing or have already been closed to accrual, the results of which will be reported shortly. Five of these trials presently accruing patients or already closed combine irinotecan with an infusional regimen of 5-FU, based on a better tolerance and efficacy profile established in the metastatic setting according to clinical trials conducted principally in Europe. The results of 2 main randomized trials in the adjuvant therapy of stage III colon cancer will be presented at the 41st Annual Meeting of the American Society of Clinical Oncology in 2005 and are eagerly awaited. These results should provide important new insights as to how to manage stage II/III colon cancer.