title: Expression of c-kit in human osteosarcoma and its relevance as a prognostic marker.
abstract: OBJECTIVE
  To examine the prognostic relevance of c-kit expression in human osteosarcomas and to evaluate the mutation status in exon 9 and exon 11 of the c-kit gene.
  
  
  METHODS
  c-kit expression was examined in 100 human osteosarcomas by immunohistochemistry using paraffin embedded tumour tissues, and capillary sequencing of genomic DNA was performed to search for mutations in exons 9 and 11 of the c-kit gene.
  
  
  RESULTS
  20 osteosarcomas showed c-kit expression ranging from 5% to 90% (mean 5.9%; SD 16.74%). Furthermore, DNA sequences of exon 9 and exon 11 of the c-kit gene were not altered in these tumours. Overall and disease free survival analysis did not reveal any differences between patients with osteosarcoma with c-kit expression and those with c-kit negative tumours.
  
  
  CONCLUSIONS
  C-kit expression is not a prognostic marker in patients with osteosarcoma. The protein expression is not linked to mutations in exon 9 or exon 11 of the c-kit gene. Therefore, these exons may not function as targets for treatment modalities based on the suppression of c-kit tyrosine kinase activity.
authors.affiliation: Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria. irene.sulzbacher@meduniwien.ac.at
authors.forename: Irene
authors.initials: I
authors.lastname: Sulzbacher
authors.forename: Peter
authors.initials: P
authors.lastname: Birner
authors.forename: Cyril
authors.initials: C
authors.lastname: Toma
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Wick
authors.forename: Peter R
authors.initials: PR
authors.lastname: Mazal
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002648:Child; D004252:DNA Mutational Analysis / Q000379:methods; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism*; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D019009:Proto-Oncogene Proteins c-kit