Expression of EGFR in Primary Squamous Cell Carcinoma of Lung

Background: Lung cancer is one of the leading cause of death in developing countries.Epidermal growth factor receptor (EGFR) is a transmembrane protein with cytoplasmic kinase activity that transduces important growth factor signaling from the extracellular milieu to the cell.Materials and methods: This study includes all cases of primary lung squamous cell carcinomas presented in the Department of Pathology from Jan 2011 to Dec 2013 in Sri Ramachandra Medical College.Formalin fixed paraffin embedded tissue stained with H&E were used for routine morphology.Immunohistochemical staining was done using monoclonal anti EGFR antibody by Streptavidin biotin peroxidase complex technique.Positive cases were graded as 1+, 2+, 3+ based on staining intensity.Results: A total of 149 cases of carcinoma lung were retrieved.Of these 26 (20%) were SCC.Eighty eight percent of these were EGFR positive, of which 70% showed 3+ positivity, 11% showed 2+ positivity, 7% showed 1+ positivity.Conclusion: EGFR expression appears to be significant in primary squamous cell carcinoma of the lung which aid in treating these patients with tyrosine kinase inhibitors and may improve the outcome of these patients.We conclude that EGFR marker expression is mandatory not only in lung adenocarcinomas but also in Primary squamous cell carcinoma of the lung.