A Significant Study on EGFR Mutations in Lung Carcinomas

Abstract

BACKGROUND Lung cancer is one of the leading causes of cancer related deaths among both men and women. Non-small cell lung carcinomas comprises the majority (about 75%) of lung cancers, has proven difficult to treat due to poorly understood pathological mechanism. Recent advances in cell signalling pathways that control cell survival have identified genetic and regulatory aberrations that suppress cell death, promote cell division and induce tumorogenesis. One such discovery is that of epidermal growth factor receptor. Overexpression of EGFR has been reported and implicated in pathogenesis of many human malignancies including Non- small cell carcinoma of lung. AIMS AND OBJECTIVES To study EGFR expression by immunohistochemistry in diagnosed cases of Non- small cell carcinomas of lung at our institute. To determine the value of EGFR test by IHC in predicting response to targeted therapy and clinical outcome. MATERIALS AND METHODS A retrospective and prospective study of bronchial biopsies diagnosed as Non-small cell carcinoma for a duration of two years with their expression to EGFR immunohistochemistry marker at our institute and these patients response to the targeted therapy. RESULTS Out of twenty nine (29) cases of lung malignancies majority were Non -small cell carcinomas- twenty seven cases (27), of which adenocarcinomas were seventeen (17) cases topped the list, followed by squamous cell carcinomas (5) cases, malignant epithelial lesions (3) cases and poorly differentiated carcinomas(2) cases. Small cell carcinomas were two (2) cases. Fifteen cases of non- small cell carcinomas cases showed EGFR mutations and twelve patients were started on the targeted therapy of Gefitinib and Erlonitib. All twelve of them showed good response to chemotherapy. CONCLUSIONS Most of the Non-small cell carcinomas of lung have EGFR mutations especially all adenocarcinomas in non-smokers. The clinical outcome of patients could be predicted. There is significant response to targeted chemotherapy.