title: Association of BRAF V600E Mutation and MicroRNA Expression with Central Lymph Node Metastases in Papillary Thyroid Cancer: A Prospective Study from Four Endocrine Surgery Centers.
abstract: BACKGROUND
  Studies have demonstrated an association of the BRAF(V600E) mutation and microRNA (miR) expression with aggressive clinicopathologic features in papillary thyroid cancer (PTC). Analysis of BRAF(V600E) mutations with miR expression data may improve perioperative decision making for patients with PTC, specifically in identifying patients harboring central lymph node metastases (CLNM).
  
  
  METHODS
  Between January 2012 and June 2013, 237 consecutive patients underwent total thyroidectomy and prophylactic central lymph node dissection (CLND) at four endocrine surgery centers. All tumors were tested for the presence of the BRAF(V600E) mutation and miR-21, miR-146b-3p, miR-146b-5p, miR-204, miR-221, miR-222, and miR-375 expression. Bivariate and multivariable analyses were performed to examine associations between molecular markers and aggressive clinicopathologic features of PTC.
  
  
  RESULTS
  Multivariable logistic regression analysis of all clinicopathologic features found miR-146b-3p and miR-146b-5p to be independent predictors of CLNM, while the presence of BRAF(V600E) almost reached significance. Multivariable logistic regression analysis limited to only predictors available preoperatively (molecular markers, age, sex, and tumor size) found miR-146b-3p, miR-146b-5p, miR-222, and BRAF(V600E) mutation to predict CLNM independently. While BRAF(V600E) was found to be associated with CLNM (48% mutated in node-positive cases vs. 28% mutated in node-negative cases), its positive and negative predictive values (48% and 72%, respectively) limit its clinical utility as a stand-alone marker. In the subgroup analysis focusing on only classical variant of PTC cases (CVPTC), undergoing prophylactic lymph node dissection, multivariable logistic regression analysis found only miR-146b-5p and miR-222 to be independent predictors of CLNM, while BRAF(V600E) was not significantly associated with CLNM.
  
  
  CONCLUSIONS
  In the patients undergoing prophylactic CLNDs, miR-146b-3p, miR-146b-5p, and miR-222 were found to be predictive of CLNM preoperatively. However, there was significant overlap in expression of these miRs in the two outcome groups. The BRAF(V600E) mutation, while being a marker of CLNM when considering only preoperative variables among all histological subtypes, is likely not a useful stand-alone marker clinically because the difference between node-positive and node-negative cases was small. Furthermore, it lost significance when examining only CVPTC. Overall, our results speak to the concept and interpretation of statistical significance versus actual applicability of molecular markers, raising questions about their clinical usefulness as individual prognostic markers.
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Patricia Aragon
authors.initials: PA
authors.lastname: Han
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Hyun-seok
authors.initials: HS
authors.lastname: Kim
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Soonweng
authors.initials: S
authors.lastname: Cho
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Fazeli
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Alireza
authors.initials: A
authors.lastname: Najafian
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Hunain
authors.initials: H
authors.lastname: Khawaja
authors.affiliation: 2 Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Melissa
authors.initials: M
authors.lastname: McAlexander
authors.affiliation: 3 Departments of Surgery, Mayo Clinic , Rochester, Minnesota.
authors.forename: Benzon
authors.initials: B
authors.lastname: Dy
authors.affiliation: 4 Division of Endocrine Surgery, University of Michigan Health System , Ann Arbor, Michigan.
authors.forename: Meredith
authors.initials: M
authors.lastname: Sorensen
authors.affiliation: 5 Endocrine Surgery Section, Department of Surgery, New York Presbyterian Hospital-Weill Cornell Medical Center , New York, New York.
authors.forename: Anna
authors.initials: A
authors.lastname: Aronova
authors.affiliation: 6 Laboratory Medicine and Pathology, Mayo Clinic , Rochester, Minnesota.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Sebo
authors.affiliation: 7 Departments of Pathology and Internal Medicine, University of Michigan Health System , Ann Arbor, Michigan.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Giordano
authors.affiliation: 5 Endocrine Surgery Section, Department of Surgery, New York Presbyterian Hospital-Weill Cornell Medical Center , New York, New York.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Fahey
authors.affiliation: 3 Departments of Surgery, Mayo Clinic , Rochester, Minnesota.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Thompson
authors.affiliation: 4 Division of Endocrine Surgery, University of Michigan Health System , Ann Arbor, Michigan.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Gauger
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Helina
authors.initials: H
authors.lastname: Somervell
authors.affiliation: 8 Department of Pathology, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Bishop
authors.affiliation: 8 Department of Pathology, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: James R
authors.initials: JR
authors.lastname: Eshleman
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Schneider
authors.affiliation: 2 Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Witwer
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Umbricht
authors.affiliation: 1 Endocrine Surgery, Department of Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.
authors.forename: Martha A
authors.initials: MA
authors.lastname: Zeiger
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D002291:Carcinoma, Papillary / Q000473:pathology; D003657:Decision Making; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation; D011379:Prognosis; D011446:Prospective Studies; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology; D013965:Thyroidectomy / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D048493:Proto-Oncogene Proteins B-raf; C542542:MIRN146 microRNA, human; C525710:MIR222, human; C482119:BRAF protein, human