Epidermal Growth Factor Receptor Mutations in Lung Adenocarcinomas: A Single Center Study from Iran

ABSTRACT

Introduction: Lung cancer is the fifth leading tumor in Iran, and while its incidence remains relatively low, it has been increasing steadily. Targeted therapies have brought new hope to patients with non small cell lung cancer (NSCLC). The epidermal growth factor receptor (EGFR) gene is the prototype member of the type I receptor tyrosine kinase (TK) family and plays a pivotal role in cell proliferation and differentiation. Studies from Asian countries have revealed a higher frequency of EGFR mutations than in the West. The aim of this study was to measure the frequency and type of EGFR mutations in a group of Iranian patients with lung adenocarcinomas. Methods: Formalin fixed paraffin embedded (FFPE) lung adenocarcinoma tissues from 103 Iranian patients were sequentially tested for EGFR mutations by the polymerase chain reaction (PCR) followed by direct nucleotide sequencing of exons 18, 19, 20, and 21. Patient's demographics and other clinical details were obtained from the medical records of hospitals affiliated to Iran University of Medical Sciences, Tehran, Iran. Statistical analyses were performed with SPSS v.20. Results: EGFR mutations were detected in 25/103 (24.3%) patients. The most frequent was an exon 21 point mutation (L858R) (15 patients; 60%), followed by one in exon 19 (10 patients; 40%). The frequency of EGFR mutations in never-smoker patients was significantly higher than in smokers (68% versus 32%; p < 0. 01). Conclusion: EGFR mutation frequency is higher than in the West but lower than in East Asian and almost equal to reported rates for Indian and North African populations. Smoking is negatively associated with EGFR mutations in Iranian lung adenocarcinomas.