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.
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.