Effect of EGFR amplification on survival of patients with EGFR mutation-positive non-small cell lung cancer.

e21000 Background: Epidermal growth factor receptor (EGFR) mutation is a common mutation in non-small cell lung cancer (NSCLC). Patients with EGFR mutation generally respond well to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). EGFR mutation are often co-occurring with EGFR amplification. However, the effect of EGFR amplification on the survival of patients with EGFR mutations remained unclear. Methods: Treatment-naïve adult patients with advanced NSCLC and EGFR mutation confirmed by next generation sequencing (NGS) at Fujian Provincial Hospital between April 2017 and October 2021 were enrolled in this retrospective clinical study. The patients’ clinical characteristics, gene mutations, treatment and clinical outcomes were extracted. progression-free survival (PFS) and overall response rate (ORR) were compared between EGFR amplification and non-EGFR amplification groups using the Kaplan-Meier method and log-rank test. Results: EGFR amplification and non-EGFR amplification were identified in 55 patients (36.67%) and 95 patients (63.33%), and there were no significant differences in clinical characteristics. No significant differences between the EGFR amplification and non-EGFR amplification groups in median PFS (247 vs. 214 days, P = 0.605). The ORR in EGFR amplification group is higher than non-EGFR amplification group (60.87% vs 32.69%). Conclusions: There is a tendency that EGFR amplification might not be a well predictor in EGFR mutation positive NSCLC patients treated with EGFR-TKIs.