Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) represent novel, effective tools in the management of advanced-stage non-small cell lung cancer (NSCLC). We aimed to evaluate the incidence and predictive role of EGFR gene amplification in patients with advanced-stage NSCLC treated with EGFR-TKIs.

The study included 290 patients with advanced-stage (IIIB or IV) NSCLC. Multiplex ligation-dependent probe amplification (MLPA) and polymerase chain reaction (PCR) were used for detection of EGFR gene amplification and EGFR mutations, respectively.

EGFR amplification was detected in 26 (9.0%) patients. EGFR amplification was found more frequently in patients harboring the EGFR mutation (p<0.001). No significant corelation between EGFR gene amplification and survival was observed.

EGFR gene amplification is associated with EGFR gene mutation. EGFR gene amplification is not a feasible predictive biomarker for treatment with EGFR-TKIs in patients with advanced-stage NSCLC.