A comparison of EGFR mutation status in tissue and plasma cell-free DNA detected by ADx-ARMS in advanced lung adenocarcinoma patients

Previous studies have shown that there are different methods used to detect the epidermal growth factor receptor ( ) mutation status in plasma cell-free DNA (cfDNA) for advanced lung adenocarcinoma patients including the ADx-Amplification Refractory Mutation System (ADx-ARMS). We explored the performance of the ADx-ARMS in detecting the mutations in cfDNA. This prospective cohort study enrolled patients who presented with advanced (stage IIIb/IV) lung adenocarcinoma. mutations in plasma cfDNA and tumor tissues by ADx-ARMS were detected. Next-generation sequencing (NGS) in plasma was performed in patients with inconsistent gene region mutations in the plasma and matched tissue samples. We calculated the clinical parameters of the ADx-ARMS for mutation status in the plasma of cfDNA, using the tumor tissues as the standard for measurement. The objective response rate (ORR) and progression-free survival (PFS) were also calculated for patients receiving first-generation EGFR-tyrosine kinase inhibitors (TKIs) therapy. In total, 203 patients were included in the final analysis. Mutations were discovered in 58.6% (119/203) of the tumor tissues and 31.0% (63/203) were detected mutations in both tumor tissues and matched plasma. The sensitivity and the specificity setting for detecting the mutations in the plasma using the ADx-ARMS were configured to 52.9% and 98.8%. An ORR of 64.8% was observed among the 71 patients who were identified as being -positive in their tumor tissues, who had received treatments using Gefitinib or Icotinib. Next, the ORR was observed to be 69.0% among the 42 patients with an mutation in their plasma. The median PFS of the patients with an mutation in tumor tissues and plasma were 10.0 11.0 months (P=0.175). The median PFS of the patients with an wild-type in the plasma was 8.7 months, which was significantly shorter than the mutant-type in plasma (P=0.001). Using ADx-ARMS as an approach with high specificity but moderate sensitivity to detect the mutations in plasma cfDNA and mutation status in plasma cfDNA using the ADx-ARMS can predict the tumor response for EGFR-TKIs.