[Efficacy of cetuximab in therapy of metastatic colorectal cancer: a system evaluation].

Objective: To assess the clinical efficacy of cetuximab in the treatment of individuals with metastatic colorectal cancer.

Methods: Literature searches were performed on all clinical trails reported on target-therapy agent cetuximab in treating metastatic colorectal cancer prior to August 2008. The basic characteristics and clinical efficacy data of trials meeting the screening criteria were extracted. Date analysis was performed by RevMan 4.2 if the data came from randomized controlled trials with the same objective.

Results: According to the selection criteria, 22 clinical studies were included. There were 8 randomized controlled trials, 1 non-randomized controlled trial and 13 single group trials. Because of different study objectives of 8 randomized controlled trials, no data could be analyzed by the Meta-analysis method. Cetuximab plus irinotecan as second-line therapy for patients with EGFR-expressing metastatic colorectal cancer who had previously failed to respond to irinotecan-added therapy could reach a tumor response rate of 16.4% - 23.0%, and median overall survival duration of 8.6 - 10.7 months. The addition of cetuximab to irinotecan as first-line therapy to treat metastatic colorectal cancer resulted in a tumor response rate of 42.0% - 67.0%, and median overall survival duration of 33.0 months. The response rate of cetuximab combined with oxaliplatin/5-FU/LV as first-line therapy for metastatic colorectal cancer was 46.0% - 72.0% and the median duration of overall survival was 28.2 - 30.0 months. Compared with the colorectal cancer population with mutant KRAS, the patients with wild-type KRAS could obtain a higher response rate and a longer progression-free survival.

Conclusion: Cetuximab in combination with chemotherapy has promising efficacy in the therapy of metastatic colorectal cancer, and status of gene KRAS is an independent predictive marker for response of cetuximab.