Prognostic Effect of Epidermal Growth Factor Receptor and EGFRvIII in Glioblastoma Multiforme Patients

PURPOSE: The epidermal growth factor receptor (EGFR) is overexpressed in approximately 50% to 60% of glioblastoma multiforme tumors, and the most common EGFR mutant, EGFRvIII, is expressed in 24% to 67% of cases. We sought to determine whether glioblastoma multiforme expression of either overexpressed wild-type EGFR or the mutant EGFRvIII is an independent predictor of overall patient survival. EXPERIMENTAL DESIGN: Glioblastoma multiforme patients (n = 196) underwent a > or =95% volumetric tumor resection followed by conformal radiation. Their EGFR and EGFRvIII status was determined by immunohistochemistry and survival analyses were done. RESULTS: In our study of glioblastoma multiforme patients, 46% (n = 91) failed to express EGFR, 54% (n = 105) had overexpression of the wild-type EGFR, and 31% (n = 61) also expressed the EGFRvIII. Patients within groups expressing the EGFR, EGFRvIII, or lacking EGFR expression did not differ in age, sex, Karnofsky performance scale score, extent of tumor resection, or radiation. The median overall survival times for patients with tumors having EGFR expression absent, overexpressed only, or mutant (EGFRvIII) were 0.96, 0.98, and 1.07 years, respectively. However, for patients surviving > or =1 year, these values were 2.03, 2.02, and 1.21 years (P or =1 year, the expression of EGFRvIII was an independent negative prognostic indicator.