In this study, we analysed 54 consecutive blood samples from 48 patients with advanced lung adenocarcinoma, carrying a druggable EGFR mutation, at progression time after treatment with first- or second-generation EGFR TKIs, using the Therascreen® EGFR RGQ PCR kit and compared the results with those obtained using two additional screening techniques: the Biocartis IdyllaTM test and an NGS-based assay. This evidence concerns the gene EGFR and lung adenocarcinoma.