title: Highly sensitive and quantitative evaluation of the EGFR T790M mutation by nanofluidic digital PCR.
abstract: The mutation of T790M in EGFR is a major mechanism of resistance to treatment with EGFR-TKIs. Only qualitative detection (presence or absence) of T790M has been described to date, however. Digital PCR (dPCR) analysis has recently been applied to the quantitative detection of target molecules in cancer with high sensitivity. In the present study, 25 tumor samples (13 obtained before and 12 after EGFR-TKI treatment) from 18 NSCLC patients with activating EGFR mutations were evaluated for T790M with dPCR. The ratio of the number of T790M alleles to that of activating mutation alleles (T/A) was determined. dPCR detected T790M in all 25 samples. Although T790M was present in all pre-TKI samples from 13 patients, 10 of these patients had a low T/A ratio and manifested substantial tumor shrinkage during treatment with EGFR-TKIs. In six of seven patients for whom both pre- and post-TKI samples were available, the T/A ratio increased markedly during EGFR-TKI treatment. Highly sensitive dPCR thus detected T790M in all NSCLC patients harboring activating EGFR mutations whether or not they had received EGFR-TKI treatment. Not only highly sensitive but also quantitative detection of T790M is important for evaluation of the contribution of T790M to EGFR-TKI resistance.
authors.affiliation: Faculty of Medical Sciences, Department of Comprehensive Clinical Oncology, Kyushu University, Fukuoka, Japan.|Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Iwama
authors.affiliation: Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Harada
authors.affiliation: Center for Clinical and Translational Research, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Isamu
authors.initials: I
authors.lastname: Okamoto
authors.affiliation: Division of Diagnostic Pathology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Ookubo
authors.affiliation: Department of Research and Development of Next Generation Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Kishimoto
authors.affiliation: Faculty of Medical Sciences, Department of Comprehensive Clinical Oncology, Kyushu University, Fukuoka, Japan.
authors.forename: Eishi
authors.initials: E
authors.lastname: Baba
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.|Center for Clinical and Translational Research, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakanishi
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods*; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage; D012680:Sensitivity and Specificity
chemical_list: D047428:Protein Kinase Inhibitors; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: EGFR; T790M; digital PCR; highly sensitive detection; quantification