Immunohistochemical detection of mutated epidermal growth factor receptors in pulmonary adenocarcinoma

Abstract

Background: Epidermal growth factor receptor (EGFR) mutational analysis has become essential in determining a therapeutic strategy for lung cancer. This study validated the reliability of recently generated rabbit monoclonal antibodies that recognise specific mutations of the EGFR protein. Patients and Methods: Pulmonary adenocarcinoma tissue from 20 previously genotyped specimens was prepared for immunohistochemical staining by two antibodies that recognise products of in-frame deletions in exon 19 (E746-A750del) and a point mutation that replaces leucine with arginine at codon 858 in exon 21 (L858R) of the EGFR gene. Results: The findings of EGFR-mutation-specific immunohistochemistry were concordant with the results of DNA analysis in 18 of 20 tested samples leading to 90% sensitivity and 100% specificity of the method. Conclusion: This immunohistochemical assay for products of representative EGFR gene mutations may be performed reliably using tissue specimens from resected pulmonary adenocarcinomas.