Expression of Epidermal Growth Factor Receptor (EGFR) in non-small cell lung carcinoma using Immunohistochemistry

Abstract

Introduction: Lung cancer is one of the leading causes of death in both men and women. It accounts for 5.9% of all cancers and 8.1% of all cancer-related deaths. Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer. It comprises different histological tumour types, including adenocarcinoma, squamous cell carcinoma and large-cell carcinoma.  Uncontrolled proliferation and the development of cancer can occur if EGFR, a transmembrane receptor tyrosine kinase protein, is mutated or overexpressed. Therefore, understanding the role of EGFR in NSCLC is vital because this protein is involved in regulating cell growth and division.

Aim: To evaluate the expression of epidermal growth factor receptor (EGFR) in non-small cell lung carcinomas using immunohistochemistry. Methods: A series of lung biopsy cases were collected from the Institute of ACS Medical College and Hospital. The tissue was fixed in formalin and taken up for routine histopathological and immunohistochemistry studies.

Results: In our study, EGFR is expressed mostly in adenocarcinoma with grades of 3+,2+ and 1+ whereas in other types of NSCLC, it is expressed in grades of 2+ and 1+. Conclusion:  In our study, we found that approximately two-thirds (>60%) of NSCLC patients express an EGFR mutation. Therefore, it is crucial to identify EGFR expression to improve patient management because it is a poor prognostic factor.