CORRELATION ANALYSIS OF EGFR GENE MUTATION FREQUENCY AND RESISTANCE TO GEFITINIB TARGETED THERAPY IN NON-SMALL CELL LUNG CANCER

Bo Gao, Wendi Xiao, Rui Shi^*

Department of Respiratory, the Second People's Hospital of Shenzhen, Shenzhen 518000, Guangdong Province, China

Objective: To explore the correlation between gene mutation frequency and resistance to gefitinib in advanced NSCLC patients with activating EGFR mutations. 

Method: The clinical data of 200 patients with stage III/IV or recurrent NSCLC who received initial gefitinib treatment in XX Hospital were retrospectively analyzed, and the relationship between EGFR mutation frequency and gefitinib resistance was analyzed. Progression-free survival (PFS) and overall survival (OS) were compared between resistant patients using Kaplan–Meier survival analysis and log-rank test.

Result: Among the 200 NSCLC specimens, the EGFR gene mutation rate was 25% (50/200), and the EGFR mutation rate in women was significantly higher than that in men (P<0.05); the incidence of gefitinib resistance in 200 patients was 28.0% (56 /200), and 38 patients had EGFR gene mutation, the mutation rate was 76.0%; in the combined molecular analysis of EGFR signaling pathway and drug resistance genes, it was found that the EGFR signaling pathway in patients with EGFR mutation also changed, and there were Patients with resistance genes had worse PFS than those without resistance genes (P<0.001). 

Conclusion: The EGFR mutation rate in NSCLC patients was significantly positively correlated with gefitinib resistance, proving that EGFR mutation may be one of the reasons for gefitinib resistance in NSCLC patients.