Radiation Combined With EGFR Signal Inhibitors: Head and Neck Cancer Focus

Molecular inhibition of epidermal growth factor receptor (EGFR) signaling represents one of the most promising current arenas for the advancement of molecularly targeted cancer therapies. A series of EGFR inhibitors from both the monoclonal antibody (mAb) and tyrosine kinase inhibitor (TKI) class have shown clear clinical activity in the treatment of several common human cancers. Three EGFR inhibitors have recently gained Food and Drug Administration (FDA) approval for cancer therapy in the United States including the mAb cetuximab (Erbitux™) and the small-molecule TKIs gefitinib (Iressa™) and erlotinib (Tarceva™). The rapidly expanding preclinical and clinical data contributing to these FDA approvals validate a central role of the EGFR as an important molecular target in epithelial malignancies. Indeed, one of the more striking clinical results in this field has been recently achieved by combining an EGFR inhibitor (cetuximab) with radiation in the treatment of advanced head and neck cancer patients. Nevertheless, the overall clinical gains realized to date with the EGFR inhibitors are modest for the global cancer population. Much remains to be learned regarding the rational integration of EGFR inhibitors into cancer treatment regimens as well as methods to optimize the selection of patients most likely to benefit from EGFR inhibitor strategies.