OBJECTIVES: This research aims to investigate the influencing factors of the therapeutic effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) in patients with advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer,to explore the acceptable cost-effectiveness that can improve treatment effect.

METHODS: 104 patients with advanced EGFR mutant NSCLC who received EGFR-TKI treatment. A correlation analysis was made between different types of EGFR mutation and the other clinical indicactors retrospectively.A Cox proportional hazard model was used to identify independent prognostic factors for PFS of patients receiving EGFR-TKI treatment, including different types of EGFR mutation and the other clinical indicactors, including the clinicopathological characteristics, hematological examination results and treatment mode.

RESULTS: The overall DCR of patients receiving EGFR-TKI treatment was 92.3%. The univariate analysis showed that the levels of CEA, CA125, D-dimer, and previous surgical treatment history of patients were associated with PFS of patients receiving EGFR-TKI treatment (respectively HR=2.464, 95%CI: 1.368-4.438; HR=2.211, 95%CI: 1.329-3.679; HR=1.866, 95%CI: 1.165-2.988; HR=0.484, 95%CI: 0.267-0.875; allP<0.05). However, there was no significant influence in the multivariate Cox analysis (HR=1.425, 95%CI: 0.723-2.809; HR=1.727, 95%CI: 0.829-3.594; HR=1.233, 95% CI: 0.667-2.280; HR=0.815, 95%CI: 0.364-1.825; all P>0.05). Type of EGFR mutation (HR=2.371, 95%CI: 1.298-4.332, P=0.005), combination therapy (HR=0.489, 95%CI: 0.245-0.978, P=0.043) and therapeutic drugs (HR=0.261, 95%CI: 0.113-0.606, P=0.002) were independent factors in the multivariate Cox analysis. After further stratification by EGFR mutation types, it was found that EGFR19 mutant patients receiving EGFR-TKI in first-line treatment could obtain better PFS than those in second-line (median PFS: 14 months vs 9.5 months, HR=2.553, 95% CI: 1.422-4.584, P=0.002). EGFR19 mutant patients with CA125<85U/ml could obtain longer PFS than those with CA125≥85U/ml (median PFS: 14 months vs 6.5 months, HR=2.537, 95 %CI: 1.426-4.512, P=0.002).

CONCLUSIONS: The therapeutic effect of EGFR-TKI in patients with advanced EGFRmutant NSCLC is positive. EGFR19-mutant NSCLC patients with low-level CA125 receivingEGFR-TKIinfirst linetreatmentcan obtain better PFS.