Epidermal Growth Factor Receptor Expression of Non-small Cell Carcinoma and Its Relationship with Genomic Mutation

ABSTRACT

BACKGROUND: It has recently been clarified that epidermal growth factor receptor (EGFR), which is a receptor tyrosine kinase of the erbB family, is abnormally activated in non-small cell lung carcinomas (NSCLC) and this fact is being utilized for creating targeted therapy. In this study, we aimed to identify the frequency of the EGFR expression and gene mutation in NSCLC, and to determine the correlation between them. METHODS: Immunohistochemical staining for EGFR, C-erbB-2, cytokeratin 7, p53 and thyroid transcription factor-1, and EGFR mutation analysis were performed using paraffin-embedded archival tissue from 228 cases of NSCLC; this included 112 squamous cell carcinomas and 116 adenocarcinomas. RESULTS: An EGFR expression and gene mutation occurred in 112 casees (53.5%) and 52 cases (22.8%), respectively. EGRF mutation was more frequent in the adenocarcinomas than in the squamous cell carcinomas, in non-smokers than in smokers, and in females than in males. EGFR mutation was significantly associated with an EGFR protein expression, and especially in adenocarcinomas. CONCLUSION: The EGFR expression in NSCLC was associated with EGFR mutation, and especially in adenocarcinomas. More studies are needed to prove the clinical significance of the EGFR expression for creating targeted therapy to treat NSCLC.