Peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp-based detection test for gefitinib-refractory T790M epidermal growth factor receptor mutation
H. Miyazawa et al
05/22/2014
Japanese Cancer Association
Mutations in the epidermal growth factor receptor (EGFR) areobserved in a fraction of non-small-cell lung cancers (NSCLS). EGFRmutation-positive NSCLS responds to gefitinib. Secondary T790Mmutation confers gefitinib resistance to NSCLS. A detection test forthe T790M mutation was designed based on the peptide nucleicacid–locked nucleic acid polymerase chain reaction clamp method.The specificity and sensitivity of the test were both greater than0.99. The test revealed that only a small population of the PC-13 cellscarried the T790M mutation. The test also revealed that the T790Mmutation was found in none of 151 NSCLC specimens obtainedbefore gefitinib treatment, whereas it was found in four of fourspecimens obtained from NSCLS that had become refractory togefitinib. In one patient in whom the L858R-positive EGFR allele wasamplified to multiple copies, an L858R-T790M double-mutant alleleemerged during the gefitinib therapy. This allele was expressedhighly. The T790M mutation detection test based on the peptidenucleic acid–locked nucleic acid polymerase chain reaction clampmethod is sensitive and specific, and is applicable to clinical practice.It detects T790M-positive cells in the course of gefitinib treatment,and thus will help to devise therapies effective for T790M-positiveNSCLS. (Cancer Sci 2008)