To detect epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients, and to study the relationship between EGFR mutation and clinical features, pathological features, the therapy efficacy.

Collect 203 NSCLC patients, specimens, including surgical specimen, lymph node tissues, transthoracic needle biopsyspecimen, bronchoscopy biopsy specimen and pleural effusion cells specimen. EGFR mutations in 203 NSCLC were analyzed by ADx-AMRS assay. The relationship between the muta-tions and the clinicopathologic features was further evaluated. And observed the clinical efficacy of EGFR-TKIs. SPSS23.0 software was used for statistical analysis, the data were compared with chi square test, PFS was calculated by Kaplan-Meier method, and the influence of various factors on survival was analyzed by Log-rank test.

The age of 203 NSCLC patients, inluding 116 male and 87 female, was range 25 years to 82 years. Smoking index was greater than or equal to 400 in 61 cases, less than 400 in 142 cases.The pathological characteristics of 203 cases were different, ininluding 152 cases of adenocarcinoma, 21 cases of squamous cell carcinoma, 14 cases of adenocarcinoma-squamous carcinoma, and other NSCLC 16 cases. The EGFR mutation rate of 203 cases in patients with NSCLC was 51.2% (104/203), including 51 deletions in exon 19(49.0%), 44 cases of exon 21 mutation, 3 cases of exon 18 mutation(2.9%), 1 case of exon 20 mutation, 3 exon 19/21 double mutation(2.9%), 1 case of 19del/T790M and 1 case of L858R/T790M. The mutation rate of 19del and L858R were higher 96.1% in 104 cases. The mutation rates of EGFR were higher in females than those in males(66.7% vs. 36.2%); Non smoking group EGFR mutation rate was higher than that in the smoking group(63.4% vs. 16.4%); EGFR mutation rate of patients, with lung adenocarcinoma was higher than that of squamous cell carcinoma(53.3% vs. 33.3%), P<0.05. Conversely, between EGFR gene mutation status and specimen type, including surgicai specimen, lymph node biopsy, lung biopsy, bronchoscopy, and pleural effusions, was no significant statistical difference (P=0.418 ). The objective response rate (ORR) to first-line TKI treatment of 101 patients was 61.4%. The disease control rate (DCR) was 71.3%, and the median progression-free survival (PFS) was 10 months. The ORR and DCR to EGFR-TKIs therapy of patients with EGFR mutation were significantly higher than those of patients with EGFR mutation/ undefined EGFR mutation (88.6% vs. 16.7% vs. 43.1%, P=0.000; 95.5% vs. 16.7% vs. 56.9%, P=0.000); the median PFS was also significantly longer (P=0.001). Furthermore, the ORR and DCR in 19-del group were higher than that of group L858R (91.2% vs. 85%, P=0.646 100%; vs. 90%, P=0.201); Patients with NSCLC in after TKI treatment, the median PFS was 14.5 months compared with 10 months in the L858R group, there were significant differences (P=0.010).

EGFR mutation rate was higher in NSCLC with the advantages of female, non smoking and adenocarcinoma. EGFR mutation detection can better predict the efficacy of molecular targeted drugs and reduce the risk of tumor progression, especialli in 19-del or L858R mutation.