title: Clinical significance of the BRAF V600E mutation in multifocal papillary thyroid carcinoma in Korea.
abstract: BACKGROUND
  We examined the frequency of the BRAF(V600E) mutation and compared the clinicopathologic features based on the BRAF(V600E) mutation status in multifocal papillary thyroid carcinoma (PTC).
  
  
  METHODS
  A total 85 patients who were diagnosed with multifocal PTC were enrolled. We confirmed the status of the BRAF(V600E) mutation in each tumor focus by the real-time polymerase chain reaction technique.
  
  
  RESULTS
  Among the 85 patients, 49 (57.6%), 34 (40.0%), and 2 (2.4%) patients were determined to have all BRAF(V600E)-positive, mixed BRAF(V600E), and all BRAF(V600E)-negative in their tumor foci, respectively. When we compared clinicopathologic features according to the BRAF(V600E) mutation status of the dominant tumor, the BRAF(V600E) -positive group (n = 70) showed more extrathyroidal invasion in the dominant tumor (32.9% vs 6.7%, P = .041) and more lymph node metastasis (67.2% vs 40.0%, P = .049) than the BRAF(V600E) -negative group (n = 15). Considering all tumor foci, the all BRAF(V600E) mutation group exhibited a younger population (P = .039), showed increased extrathyroidal invasion (38.8% vs 14.7%, P = .017) and lymph node metastasis (71.4% vs 48.4%, P = .038), and received more radioactive iodine therapy (79.2% vs 52.9%, P = .012) than the mixed BRAF(V600E) mutation group. A larger tumor size and heavier preoperative body weight was positively correlated with the relative expression of BRAF(V600E) mutation calculated by 2(-△△Ct) method.
  
  
  CONCLUSIONS
  Most of the Korean patients with multifocal PTC had the BRAF(V600E) mutation in one or more tumor foci, and all BRAF(V600E)-positive multifocal PTC showed more aggressive features.
authors.affiliation: Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Hwa Young
authors.initials: HY
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Yun Jae
authors.initials: YJ
authors.lastname: Chung
authors.affiliation: Department of Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Byung Seup
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Kang
authors.affiliation: Department of Nuclear Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Ju Won
authors.initials: JW
authors.lastname: Seok
authors.affiliation: Department of Pathology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Hee Sung
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea. Electronic address: bycho@cau.ac.kr.
authors.forename: Bo Youn
authors.initials: BY
authors.lastname: Cho
mesh_terms: D002277:Carcinoma / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D002291:Carcinoma, Papillary; D018450:Disease Progression; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf