Evaluation of the incidence and prognostic value of mutant epidermal growth factor receptor (EGFRvIII) protein expression in head and neck squamous cell carcinomas (HNSCC) using AQUA.

5538 Background: EGFR VIII represents a common form of mutant EGFR and has been described in several cancers, mainly glioblastoma. Data derived from cell line and xenograft models indicate that EGFRVIII expression is implicated in resistance to targeting wild-type EGFR in HNSCC. Two studies (Sok et al, Hama et al) have evaluated the incidence of EGFRVIII expression in HNSCC. Sok et al reported the presence of EGFRVIII in 42% of HNSCC using immunohistochemistry and reverse transcription polymerase chain reaction whereas Hama et al reported no EGFRVIII mutation in HNSCC by sequencing full-length EGFR. We sought to evaluate the incidence and prognostic significance of EGFRVIII in a cohort of HNSCC who had not received EGFR-targeted therapy. Methods: A tissue microarray composed of 102 specimens from primary HNSCC cases was constructed. Protein expression for EGFRVIII was analyzed using an immunofluorescence-based assay that provides an automated, quantitative analysis of expression within subcellular compart...