title: How to minimise the effect of tumour cell content in detection of aberrant genetic markers in neuroblastoma.
abstract: BACKGROUND
  Clinical heterogeneity reflects the complexity of genetic events associated with neuroblastoma (NB). To identify the status of all described genetic loci with possible prognostic interest, high-throughput approaches have been used, but only with tumour cell content >60%. In some tumours, necrotic, haemorrhagic and/or calcification areas influence the low amount of neuroblasts. We evaluated the effect of tumour cell content in the detection of relevant aberrant genetic markers (AGM) diagnosed by fluorescence in situ hybridisation (FISH) on tissue microarrays (TMA) in NB.
  
  
  METHODS
  Two hundred and thirty-three MYCN non-amplified primary NB included in 12 TMAs were analysed.
  
  
  RESULTS
  Presence of AGM reduced event-free survival (EFS) (P=0.004) as well as overall survival (OS) (P=0.004) of patients in the whole cohort. There were no differences in prognostic impact of presence of AGM according to tumour cell content.
  
  
  CONCLUSIONS
  We propose the use of FISH to diagnose AGM of all NB samples having the above-mentioned areas to determine patient risk.
authors.affiliation: Department of Pathology, Medical School, University of Valencia, Avda. Blasco Ibáñez, 17, 46010 Valencia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Piqueras
authors.forename: S
authors.initials: S
authors.lastname: Navarro
authors.forename: A
authors.initials: A
authors.lastname: Cañete
authors.forename: V
authors.initials: V
authors.lastname: Castel
authors.forename: R
authors.initials: R
authors.lastname: Noguera
mesh_terms: D002874:Chromosome Mapping; D005260:Female; D005784:Gene Amplification; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D000071447:N-Myc Proto-Oncogene Protein; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000145:classification / Q000175:diagnosis* / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics; D015513:Oncogene Proteins / Q000235:genetics; D011379:Prognosis; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: D005819:Genetic Markers; C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins