title: The PCR-invader method (structure-specific 5' nuclease-based method), a sensitive method for detecting EGFR gene mutations in lung cancer specimens; comparison with direct sequencing.
abstract: BACKGROUND
  Several sensitive assays, including the PCR-invader method (structure-specific 5' nuclease-based method), have been used to detect EGFR mutations in non-small-cell lung cancer (NSCLC). However, validation has not been reported. We assessed the detection rate of EGFR mutation by the PCR-invader method and direct sequencing using same clinical specimens.
  
  
  METHODS
  EGFR mutations were analyzed with the PCR-invader method and compared with direct sequencing using paraffin tissues and pleural and pericardial effusions from NSCLC patients. The relationships between the treatment responses and mutations were evaluated retrospectively.
  
  
  RESULTS
  Fifty-four samples from 42 NSCLC patients were studied. EGFR mutations were identified in 52% of the patients and 52% of the samples with the PCR-invader method, but only in 43% of the patients and in 35% of the samples by direct sequencing. In the samples obtained from the same patients at different sites and different times, EGFR mutations were coincident in nine out of ten patients by the PCR-invader method but in six out of ten patients by direct sequencing. Seventeen patients with EGFR mutations were treated with gefitinib; the response rate (RR) and disease control rate (DCR) were 41 and 94%, and median treatment duration was more than 6 months. Seven EGFR mutation-negative patients were treated with gefitinib; the RR and DCR were 0 and 14%, and median treatment duration was 1 month.
  
  
  CONCLUSIONS
  The PCR-invader method was useful for detecting EGFR mutations in clinical lung cancer specimens and is more sensitive than direct sequencing.
authors.affiliation: Division of Pulmonary Medicine, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan. knaoki@pg7.so-net.ne.jp
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Naoki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Soejima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
authors.forename: Junko
authors.initials: J
authors.lastname: Hamamoto
authors.forename: Naoya
authors.initials: N
authors.lastname: Hida
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakachi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasuda
authors.forename: Sohei
authors.initials: S
authors.lastname: Nakayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoda
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Satomi
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Ikemura
authors.forename: Hideki
authors.initials: H
authors.lastname: Terai
authors.forename: Takashi
authors.initials: T
authors.lastname: Sato
authors.forename: Koshiro
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D004252:DNA Mutational Analysis; D003851:Deoxyribonucleases; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: C512478:EGFR protein, human; D066246:ErbB Receptors; D003851:Deoxyribonucleases