title: BRAF (V600E) mutation analysis on liquid-based cytology-processed aspiration biopsies predicts bilaterality and lymph node involvement in papillary thyroid microcarcinoma.
abstract: BACKGROUND
  Activating mutations in the valine-to-glutamic acid substitution at position 600 of the v-raf murine sarcoma viral oncogene homolog B1 (BRAF-1) gene are detected frequently in patients with papillary thyroid carcinoma (PTC). These mutations have been identified in approximately 29% to 69% of PTCs and in >80% of PTCs of the tall cell variant, whereas they have not been detected in benign lesions or in the majority of those (80%) with the follicular variant of PTC. The objective of the current study was to evaluate the role of liquid-based cytology (LBC) for the detection of BRAF mutations in the outcome of patients who have thyroid PTC measuring ≤ 1 cm and, hence, in guiding their clinical and surgical management.
  
  
  METHODS
  From October 2010 through June 2011, 230 consecutive cases were diagnosed as positive for malignancy on fine-needle aspiration cytology processed by LBC. Of these, 73 PTCs ≤ 1 cm underwent BRAF mutational analysis. The aspirated material was processed using an LBC technique. After DNA extraction of the residual material, BRAF mutation analysis was performed using a direct sequencing method.
  
  
  RESULTS
  Fifty of 73 patients (68.5%) underwent surgery, and 34 of those patients (68%) had tumors that expressed a BRAF mutation (31 PTCs, including 11 tall cell variants and 3 follicular-variant PTCs). A significant association between BRAF mutation and bilaterality of cancer was observed (odds ratio, 0.077; P = .0007). BRAF mutation was associated significantly with lymph node involvement (odds ratio, 19; P = .0007) but not with extracapsular infiltration (odds ratio, 0.298; P = .179).
  
  
  CONCLUSIONS
  The current results indicated that BRAF gene mutations can be identified successfully on LBC material and using other cytologic methods with high reproducibility, feasibility, and informative results. The presence of a BRAF mutation may preoperatively predict the behavior of microscopic PTC, suggesting a more aggressive surgical approach.
authors.affiliation: Division of Anatomic Pathology and Histology, Agostino Gemelli School of Medicine, Catholic University of Sacred Heart, Rome, Italy. esther.rossi@rm.unicatt.it
authors.forename: Esther Diana
authors.initials: ED
authors.lastname: Rossi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Martini
authors.forename: Sara
authors.initials: S
authors.lastname: Capodimonti
authors.forename: Celestino Pio
authors.initials: CP
authors.lastname: Lombardi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pontecorvi
authors.forename: Valerio Gaetano
authors.initials: VG
authors.lastname: Vellone
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Zannoni
authors.forename: Luigi Maria
authors.initials: LM
authors.lastname: Larocca
authors.forename: Guido
authors.initials: G
authors.lastname: Fadda
mesh_terms: D044963:Biopsy, Fine-Needle; D001707:Biopsy, Needle; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000235:genetics* / Q000601:surgery; D003581:Cytodiagnosis; D004247:DNA / Q000235:genetics; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D013961:Thyroid Gland / Q000473:pathology* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000601:surgery
chemical_list: D004247:DNA; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf