Analysis of the EGFR gene mutation in patients with nonsmall cell lung cancer in a Chinese population

Purpose: To investigate the epidermal growth factor receptor (EGFR) gene mutations and analyze their clinical significance in patients with non-small cell lung cancer (NSCLC) in Hubei province of China.
Methods: A total of 138 paraffin embedded tissues were taken from patients with NSCLC who were treated at Hubei Hospital from January 2014 to June 2015. The tissue DNA was extracted and EGFR mutation was evaluated by polymerase chain reaction (PCR) sequencing analysis of exons 18, 19, 20, and 21.
Results: The overall mutation rate of EGFR gene was 30.43 % (42/138) in 138 NSCLC patients. The mutation rates of EGFR gene at exon 18, 19, 20, 21 were 0 %（0/138), 13.8 %（19/138), 0.7 % (1/138) and 15.9 % (22/138), respectively. The mutation rate of EGFR gene was higher in female patients than that in males (62.2 % (28/45) vs 15.1 % (14/93), p < 0.01), and higher in non-smoking patients than in smoking ones (p < 0.05), but had no correlation with age in NSCLC patients (p > 0.05). EGFR mutation frequency in adenocarcinoma was higher than that in squamous cell carcinoma: 33.9 % (41/121) vs. 5.9 % (1/17, p < 0.05).
Conclusion: EGFR mutations in NSCLC patients mainly exist in exons 19 and 21, and the mutation rate of exon 21 is higher than that of exon 19, which is more commonly found in female, adenocarcinoma and non-smoking patients.

Keywords
Non-small cell lung cancer; Epidermal growth factor receptor (EGFR); Targeted therapy; Sequencing