EGFRvIII Expression in Squamous Cell Carcinoma of the Skin

Abstract

Cutaneous squamous cell carcinoma (SCC) is a common cancer with an estimated 200 000 new cases annually.¹ It is usually readily curable. However, a small subset of SCC tumors (approximately 10%, or 20 000 cases annually), termed “high-risk SCC,” carries an elevated risk of metastasis and death and accounts for nearly all the mortality associated with SCC.² Epidermal growth factor receptor (EGFR) is overexpressed in a large percentage of SCC. Several therapeutic trials using EGFR blockade (with agents such as lapatinib, erlotinib, or panitumumab) to treat high-risk or metastatic SCCs are ongoing.³ Cetuximab, a chimeric IgG1 monoclonal antibody against EGFR, has been considered and used in the treatment of SCC; however, formal trials have not been performed, and good data are lacking.⁴ The most common form of mutant EGFR, called EGFRvIII, has been described in several cancers, including head and neck cancer. It has been shown that EGFRvIII contributes to enhanced growth of SCC and resistance to EGFR inhibitor drugs.⁵The aim of this study was the assessment of wild-type EGFR (wtEGFR) and EGFRvIII expression in skin SCC and its correlation with tumor biology.