Analysis of EGFR Gene Mutations in Lung Adenocarcinoma in Karamay, Xinjiang

Abstract

To investigate the mutation types and mutation rate of the epidermal growth factor receptor (EGFR) gene in patients with lung adenocarcinoma and the clinical features of lung adenocarcinoma with EGFR gene mutations in Karamay, Xinjiang, China. Paraffin-embedded tissue samples of adenocarcinoma patients were collected in the Karamay Central Hospital from March 2016 to June 2019, and mutations in exon 18–21 of the EGFR gene were detected by the allele-specific amplification polymerase chain reaction (Amplification Refractory Mutation System–PCR) method. The relationships between the mutation types, mutation incidence, and clinical features were analyzed. Of the 170 patients with lung adenocarcinoma, 83 had EGFR mutations. The total mutation rate of EGFR in patients with lung adenocarcinoma was 48.8%, which included mutations in exons 18 (1.2% [2/170]), 19 (19.4% [33/170]), 20 (2.4% [4/170]), and 21 (20.6% [35/170]). Intriguingly, there was a case with 9 mutations in exons 20 and 21. The mutations in exon 19 of EGFR resulted in the deletion of codons 746 to 750. The main mutation in exon 21 was L858R (91.4% [32/35]). There was no significant difference in exons 19 and 21 mutation rates (P > 0.05). The mutation rate of EGFR in female patients was significantly higher than that in male patients (P < 0.05) but had no correlation with the age, smoking status, and clinical stage of patients with non–small cell lung cancer (P > 0.05). The EGFR mutation rate may be related to the degree of tumor differentiation. Among patients with lung adenocarcinoma in Kelamayi (city in Xinjiang), EGFR mutations were more frequently detected in female patients, and the main sites of mutations were exons 19 and 21.