title: A comparison of immunohistochemical and molecular methods used for analyzing the BRAF V600E gene mutation in malignant melanoma in Taiwan.
abstract: OBJECTIVE
  The BRAF V600 mutation has been shown to be clinically meaningful in terms of both the prognosis and sensitivity of BRAF inhibitors in patients with metastatic melanoma. Recently, a BRAF V600E mutation-specific antibody, VE1, was generated for the detection of tumors bearing BRAF V600E mutations. To determine the clinical value of immunohistochemical testing, we compared the prevalence of mutant BRAF detected by VE1 with direct sequencing results.
  
  
  METHODS
  Paraffin-embedded, formalin-fixed melanoma biopsies were analyzed for the BRAF mutation status by immunohistochemistry with the VE1 antibody. Sanger sequencing was applied to verify the immunohistochemical results.
  
  
  RESULTS
  A total of 73 melanoma cases with tumor samples from primary lymph nodes and metastatic sites were selected for this study. Direct sequencing demonstrated that 18 of 73 cases (24.6%) harbored the BRAF V600 mutation: 17 with V600E and one with V600K. All 18 tumors shown to harbor the BRAF V600E/K mutations were VE1-positive. One additional case was false-positive for VE1. The sensitivity and specificity of VE1 was 100% (18/18) and 98% (54/55), respectively. The overall concordance between the immunohistochemical method and direct sequencing was excellent (98.6%).
  
  
  CONCLUSIONS
  Our findings demonstrate that immunohistochemical analysis using VE1 constitutes a highly sensitive test for the detection of BRAF mutations and suggest that this cost-effective method is suitable as a rapid diagnostic approach complementary to molecular testing.
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Wen-Kuan
authors.initials: WK
authors.lastname: Huang
authors.affiliation: Department of Pathology, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Tseng-Tong
authors.initials: TT
authors.lastname: Kuo
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Chiao-En
authors.initials: CE
authors.lastname: Wu
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Cheng
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Chia-Hsun
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.|Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Jia-Juan
authors.initials: JJ
authors.lastname: Hsieh
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.|Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Yung-Chi
authors.initials: YC
authors.lastname: Shen
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Ming-Mo
authors.initials: MM
authors.lastname: Hou
authors.affiliation: Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Todd
authors.initials: T
authors.lastname: Hsu
authors.affiliation: Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: John Wen-Cheng
authors.initials: JW
authors.lastname: Chang
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000737:chemistry; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000737:chemistry* / Q000235:genetics* / Q000556:secondary; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000032:analysis* / Q000235:genetics*; D012680:Sensitivity and Specificity; D013624:Taiwan
chemical_list: D014408:Biomarkers, Tumor; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF V600E; immunohistochemistry; melanoma