title: Pathogenetic Implications of BRAF Mutation Distribution in Stage IV Melanoma Patients.
abstract: BACKGROUND
  BRAF mutation frequencies in melanoma subtypes have clinical implications and offer pathogenetic clues.
  
  
  OBJECTIVE
  To characterize BRAF mutation status in melanoma of unknown primary (MUP) patients, in histological melanoma subtypes and by localization of primary tumors.
  
  
  METHODS
  In 179 patients with stage IV metastatic melanoma, BRAF mutation status, histological subtype and localization of primary (except for 29 MUP patients) were analyzed.
  
  
  RESULTS
  BRAF mutations were found in 44.3%, of which 80.5% were BRAF V600E and 19.5% showed non-V600E BRAF mutations. BRAF mutation frequency depended on histological subtype (57.4% superficial spreading melanoma, 54.7% nodular melanoma, 11.1% mucosal melanoma, 28.6% acral lentiginous melanoma) and concerning non-V600E BRAF mutations on localization of primary. In MUP the BRAF mutation pattern resembled superficial spreading and nodular melanomas.
  
  
  CONCLUSIONS
  BRAF mutation frequencies depend on histological subtype and localization of primary melanoma. Non-V600E BRAF mutations mostly occur in patients with primaries on 'head and neck' as well as 'trunk' but not on 'extremities'.
authors.affiliation: Department of Dermatology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Baiter
authors.forename: Gerold
authors.initials: G
authors.lastname: Schuler
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.forename: Regine
authors.initials: R
authors.lastname: Schneider-Stock
authors.forename: Lucie
authors.initials: L
authors.lastname: Heinzerling
mesh_terms: D005121:Extremities; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000473:pathology / Q000556:secondary; D009092:Mucous Membrane; D059645:Mutation Rate; D009367:Neoplasm Staging; D009382:Neoplasms, Unknown Primary / Q000235:genetics* / Q000473:pathology; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology / Q000556:secondary; D060726:Torso
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf