Epidermal growth factor receptor revisited: prognostic marker or target for therapy?

摘要

Colorectal cancer is the number two cause of cancer deaths for both sexes worldwide (Cancer Facts and Figures. 2010). Despite aggressive treatment, the clinical response rate for metastatic colorectal cancer is less than 39%. Often it is difficult to determine at the time of the primary tumor resection which patients have metastatic disease and which will have a worse prognosis. To address this issue, numerous studies have been conducted to establish reliable prognostic markers for survival of metastatic colon cancer. The studies have identified markers for prognosis, metastasis and targets for therapy. One such marker is the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase that is activated or overexpressed in a large percentage of tumors; including colorectal cancer, although there have been conflicting reports as to whether EGFR expression correlates with poor prognosis.