Targeted therapies in the treatment of colorectal cancers.

BACKGROUND: In solid organ malignancies, no tumor type has seen a greater impact from the development of novel targeted therapies in 2004 than metastatic colorectal cancer. METHODS: We review the current progress to date with the use of monoclonal antibodies in colorectal cancer and look at newer therapies under investigation. RESULTS: Two monoclonal antibodies received Food and Drug Administration approval in early 2004, both for the indication of advanced, metastatic colorectal cancer. A large, randomized, placebo-controlled study demonstrated that the addition of a monoclonal antibody to vascular endothelial growth factor, bevacizumab, led to a statistically significant improvement in overall survival, with tolerable additional toxicity. Chimeric monoclonal antibody therapy directed at the epidermal growth factor receptor was associated with radiographic responses in a significant minority of patients with irinotecan-refractory colon cancer in a randomized phase II study of patients with irinotecan-refractory disease. CONCLUSIONS: These dramatic successes have led to further clinical studies of targeted therapy in colorectal cancer, making it one of the most promising areas of cancer research.