Overexpression of EGFR pathway-related genes in the circulation is highly correlated with EGFR mutations and overexpression in paired cancer tissue from patients with non-small cell lung cancer.

Epidermal growth factor receptor (EGFR)-directed tyrosine kinase inhibitors (TKIs) have been established as a treatment option in patients with advanced non-small cell lung cancer (NSCLC). Clinically, PCR and RFLP are commonly used to evaluate the efficacy of TKIs, and these methods require cancer tissues to proceed. In the event a peripheral blood test is able to replace current evaluation methods, a greater clinical application advantage may be achieved. Therefore, in this study, we selected 30 EGFR pathway-related genes and constructed activated EGFR chips to identify overexpression of EGFR pathway-related genes from the peripheral blood of 72 NSCLC patients and 100 normal subjects. According to ROC curve analysis, the best chip interpretation cutoff value was 11 genes. Correlation analysis showed high significance among EGFR mutations, overexpression and the overexpression of EGFR pathway-related genes (p<0.0001). The potential application of this new technique may provide an accurate, instantaneous and convenient drug evaluation tool.