Effective detection of the epidermal growth factor receptor mutation in pathologic specimens of non-small cell lung cancer patients by a rapid and sensitive detection system, the peptide nucleic acid-locked nucleic acid PCR Clamp

Abstract

20113 Background: EGFR mutations link to the responsiveness to gefitinib, so it is important to get result of EGFR mutations more rapidly and sensitively. Methods: We screened 14 trans-bronchial lung biopsy (TBLB) specimens of non-small cell lung cancer (NSCLC) patients; 10 patients responded to gefitinib and 4 patients did not respond to gefitinib. We examined exons 18 through 21 (the area of the EGFR gene coding for the tyrosine kinase domain) both by the PNA-LNA PCR clamp method and the conventional sequence method. Results: We found five different mutations in 9 patients of 10 who responded to gefitinib by the PNA-LNA PCR clamp method, but only in 7 patients by the conventional sequence method. Detected mutations were the point mutation of exon 18(719S) and exon 21(858R), deletions of exon 19 (E746-A750del (nt2235–2249), E746-A750del (nt2236–2250), L747-E749del A750P). All 4 patients who did not respond to gefitinib were not detected any EGFR mutations either by the PNA-LNA PCR clamp method or by the conventional sequence method. We could get result for 2 days by the PNA-LNA PCR method, but by 7 days by the conventional sequence method routinely. Conclusions: The PNA-LNA PCR clamp method is more sensitive and rapid than the conventional sequence method. The detected EGFR mutations have good relation to gefitinib response. No significant financial relationships to disclose.