Evaluation of Epidermal Growth Factor Receptor Gene  Mutations in an Iranian Population with Non-Small Cell Lung Carcinoma

Hamzeh  Salmani; Mahin  Yahyaei; Reza  Raoofian; Shiva  Irani; Iman  Salahshouri Far; Seyed Mohammad  Akrami

doi:10.18502/ijph.v51i2.8698

Hamzeh Salmani Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Mahin Yahyaei Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Reza Raoofian Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
Shiva Irani Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Iman Salahshouri Far Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Seyed Mohammad Akrami Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/ijph.v51i2.8698

Keywords: Non-small cell lung cancer (NSCLC); Epidermal growth factor receptor (EGFR); Gene Mutation; Clinicopathological data; Iran

Abstract

Background: Mutations of the epidermal growth factor receptor (EGFR) gene, predominantly in exons 18-21, have been highlighted to function as the crucial predictors of the response rate of patients with non-small cell lung cancer (NSCLC) to EGFR tyrosine kinase inhibitors (TKIs).

Methods: This study was performed at Tehran University of Medical Sciences. Data and information were retrospectively collected from the period between Dec 2010 and Apr 2014. Exons 18 to 21 of the EGFR were analyzed for any potential mutation by PCR, accompanied by DNA sequencing on 160 with pathological confirmation of NSCLC.

Results: Demographically, the male to female ratio was approximately 2:1, and a substantial difference in age between sexes was not observed (P=0.065), but a noticeable difference was found in the smoking variable, where 77.8% of males were smokers compared to 17.3% of women (odds ratio (OR) (95% CI) = 16.72 (7.15-39.11)). We found a frequency of 10.63% (17/160) for mutations found in exons 19 and 21, nonetheless, no mutations in exon 18 and exon 20 were observed. The most frequently observed mutations were c.2235_2249, del and c.2240_2257, del in exon 19 and p. L858R in exon 21. The c.2253A>G was found as a novel mutation that was the rarest mutation detected in this work. Interestingly, a remarkable negative association was revealed between smoking and mutation rates in NSCLC patients (OR (95% CI) = 0.13 (0.04- 0.46).

Conclusion: The occurrence of EGFR mutations is largely varied among the different states of Iran, probably due to variations in ethnicity, smoking rate, and sex ratio of participants.