Epidermal growth factor receptor inhibitors for the treatment of colorectal cancer: a promise fulfilled?

The epidermal growth factor receptor (EGFR) is commonly expressed in colorectal cancers but not in most normal tissues, raising the possibility that this receptor could serve as a target for highly selective therapy. Based on preclinical studies demonstrating that antagonists of EGFR resulted in the inhibition of tumor growth, the development of clinical reagents has been aggressively pursued. Early clinical studies demonstrated antitumor activity of EGFR inhibitors in patients with advanced colorectal cancer, with acceptable toxicity. This early success fueled rapid clinical development. In this article, we will review the current status of EGFR inhibitors in the treatment of patients with colorectal cancer, in an effort to describe both how far we have come as well as where we need to go in optimizing this promising therapeutic approach.