Abstract: Objective  To evaluated the effect of first-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) on advanced non-small cell lung cancer (NSCLC) patients with different EGFR mutation status (exon 19 deletion and exon 21 mutation). Methods  Seventytwo advanced NSCLC patients with EGFR mutation confirmed by histopathology were enrolled. All of the patients received firstline EGFRTKI. The relationships between EGFR mutation status and objective response rate (ORR), disease control rate (DCR), progression free survival (PFS) and overall survival (OS) were analyzed. Results  Of the 72 patients, 37 patients expressed exon 19 deletion, 35 patients expressed exon 21 mutation, and all of them could be evaluated. The ORR and DCR of patients with exon 19 deletion were higher than those of patients with exon 21 mutation (75.7% vs. 51.4%, χ²=4.583, P=0.032; 89.2% vs. 68.6%, χ²=4.636, P=0.031). The modified median PFS of patients with exon 19 deletion was significantly higher than that of patients with exon 21 mutation (13.2 month vs. 10.8 month, χ²=4.700, P=0.030). The median OS of patients with exon 19 deletion was significantly higher than that of patients with exon 21 mutation (30.2 month vs. 25.6 month, χ²=4.686, P=0.030). The side effects were similar between the two groups. The most common adverse reaction was rash, and the incidence had no significant difference between the two groups (48.7% vs. 48.6%, χ²=0.000, P=0.995). Conclusion   EGFR mutation status is a predictor for PFS, OS and ORR of first-line EGFR-TKI in patients with advanced NSCLC. NSCLC patients with EGFR exon 19 deletion are associated with longer survival time and better response rate compared with those with exon 21 mutation.

Key words: Receptor, epidermal growth factor, Carcinoma, non-small-cell lung, EGFR-TKI