Targeted therapy in colorectal cancer.

Adjuvant therapy can reduce the risk of disease recurrence in patients with stage II-IV colorectal cancer. Recently, 3 monoclonal antibodies have been shown to improve clinical outcome in this group of patients. Bevacizumab is an antiangiogenesis agent that has been shown in clinical and preclinical models to reverse the effects of proangiogenic molecules. Bevacizumab is active in the adjuvant setting and in the treatment of metastatic disease. Cetuximab is targeted to the epidermal growth factor receptor. Panitumumab is a fully human immunoglobulin G2 antibody that also binds to the epidermal growth factor receptor. Combination therapies of monoclonal therapies and chemotherapy have resulted in better clinical outcomes than with either modality alone.