title: High-throughput screening of extended RAS mutations based on high-resolution melting analysis for prediction of anti-EGFR treatment efficacy in colorectal carcinoma.
abstract: OBJECTIVE
  Recent studies have demonstrated that, in advanced colorectal carcinoma (CRC) patients, extended RAS (in KRAS exons 2-4 and NRAS exons 2-4) and BRAF mutations are negative predictors for anti-EGFR treatment efficacy and negative prognostic factor, respectively. Thus, high-throughput and cost-effective methods for identification of the mutation status are required.
  
  
  METHODS
  We developed a PCR-high-resolution melting (HRM)-based method for screening extended RAS and BRAF mutations, and relative frequency of mutations in formalin-fixed paraffin-embedded samples of CRC was analyzed.
  
  
  RESULTS
  Among 93 CRC samples, 29 harbored mutations in KRAS exon 2, and 9 harbored mutations in BRAF exon 15. Analysis of 55 KRAS exon 2 and BRAF exon 15 wild-type CRC samples identified the following mutations: 1/55 in exon 3 and 2/55 in exon 4 of KRAS; 1/55 in exon 2, 3/55 in exon 3, and 0/55 in exon 4 of NRAS.
  
  
  CONCLUSIONS
  Our PCR-HRM method will enable rapid determination of the extended RAS and BRAF mutation status prior to anti-EGFR treatment in the clinical setting.
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan. Electronic address: ishige.t@chiba-u.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ishige
authors.affiliation: Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Sakae
authors.initials: S
authors.lastname: Itoga
authors.affiliation: Department of Medical Technology and Sciences, International University of Health and Welfare, Fukuoka, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kitamura
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Motoi
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Setsu
authors.initials: S
authors.lastname: Sawai
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Matsushita
authors.affiliation: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Pathology, Chiba University Hospital, Chiba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ota
authors.affiliation: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyauchi
authors.affiliation: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Hisahiro
authors.initials: H
authors.lastname: Matsubara
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Pathology, Chiba University Hospital, Chiba, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani
authors.affiliation: Department of Molecular Diagnosis, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Nomura
mesh_terms: D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics; D004252:DNA Mutational Analysis / Q000379:methods; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005091:Exons / Q000235:genetics; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D009154:Mutation; D009691:Nucleic Acid Denaturation; D017063:Outcome Assessment, Health Care / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D015203:Reproducibility of Results; D018631:ras Proteins / Q000235:genetics*
chemical_list: D066246:ErbB Receptors; D048493:Proto-Oncogene Proteins B-raf; D018631:ras Proteins
keywords: Anti-EGFR treatment; Colorectal carcinoma; Extended RAS; High-resolution melting