Current issues in the targeted therapy of advanced colorectal cancer.

Currently used cytotoxic drugs in the treatment of advanced colorectal cancer (ACC) are primarily the fluoropyrimidines, irinotecan, and oxaliplatin. The introduction of targeted therapy has increased the therapeutic arsenal. Two classes of monoclonal antibodies have been approved for clinical use in ACC: bevacizumab, an antibody against the vascular endothelial growth factor (VEGF), and cetuximab and panitumumab, antibodies against the epidermal growth factor receptor (EGFR). We review the current status of targeted therapy and the mechanism of action of monoclonal antibodies in ACC.