Epidermal growth factor receptor (EGFR) mutations are predictive marker of EGFR-tyrosine kinase inhibitor (TKI) therapy. We compared the sensitivity of EGFR mutation detection techniques between matched tumor tissue and peripheral blood sample in patients with lung adenocarcinoma.
We collected the paired samples from plasma and paraffin-embedded tumor tissue in 295 patients before EGFR-TKIs therapy. DNA extraction was performed using the QIAamp MinElute virus spin kit and EGFR mutation analysis was done by two detection methods. One is the PNAClamp™ (Clamp) which is the PNA-based PCR clamping that selectively amplifies only the mutated target DNA sequence as minor portion in mixture with the major wild type DNA sequences. The other is the PANAMutyper™ EGFR kit (Mutyper), which use PNA clamping-assisted fluorescence melting curve analysis to perform mutation detection and genotyping.
In tissue samples, the positive rates of EGFR sensitive mutation were not different between two methods (26.8% in Mutyper vs. 24.7% in Clamp). Plasma sensitivity was significantly higher in Mutyper than Clamp (70.9% vs. 30.1%, p
The plasma sensitivity and concordance of Mutyper were better than Clamp test. And Mutyper could better predict the PFS of EGFR mutation in plasma. So this technique is expected to be useful to detect EGFR mutation in circulating cell-free DNA sample.
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This research was financially supported by grants from the Panagene Inc.
All authors have declared no conflicts of interest.