title: Clinical significance of MYCN amplification and ploidy in favorable-stage neuroblastoma: a report from the Children's Oncology Group.
abstract: OBJECTIVE
  MYCN amplification is rarely detected in patients with favorable-stage neuroblastoma (NB). To determine the clinical significance of MYCN amplification in children with favorable-stage NB, we performed a retrospective review of data from the Pediatric Oncology Group (POG) biology study 9047.
  
  
  METHODS
  MYCN status, tumor cell ploidy, treatment, and outcome of patients with stage A, B, or Ds NB, enrolled on POG 9047 between 1990 and 1999 were analyzed. Event-free survival (EFS) and overall (OS) survival rates were analyzed using the Kaplan-Meier method.
  
  
  RESULTS
  Of the 1,667 patients enrolled on POG 9047, 643 had favorable-stage disease. Of these, follow-up data were available on 568 (34%) with stage A, B, or Ds disease and normal MYCN copy number, and 32 (1.9%) patients with MYCN-amplified, stage A, B, or Ds tumors. Within the cohort lacking MYCN amplification, the 7-year EFS and OS rates (+/- SE) were 91% +/- 1% and 96% +/- 1%, respectively. Patients with MYCN amplification had significantly worse EFS and OS (50% +/- 9% and 59% +/- 9%, respectively, P < .0001). Within the cohort of children with MYCN amplification, the 7-year EFS and OS rates were 80% +/- 10% and 87% +/- 9%, respectively for patients with hyperdiploid tumors and 25% +/- 11% and 38% +/- 12% for patients with diploid/hypodiploid NBs (P = .0063 and P = .0074, respectively).
  
  
  CONCLUSIONS
  Tumor cell ploidy may be a clinically useful factor for prognostication and treatment stratification in children with MYCN-amplified, favorable-stage NB tumors.
authors.affiliation: Children's Memorial Hospital, Department of Pediatrics, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Schneiderman
authors.forename: Wendy B
authors.initials: WB
authors.lastname: London
authors.forename: Garrett M
authors.initials: GM
authors.lastname: Brodeur
authors.forename: Robert P
authors.initials: RP
authors.lastname: Castleberry
authors.forename: A Thomas
authors.initials: AT
authors.lastname: Look
authors.forename: Susan L
authors.initials: SL
authors.lastname: Cohn
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004171:Diploidy; D018572:Disease-Free Survival; D005260:Female; D005784:Gene Amplification; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D000071447:N-Myc Proto-Oncogene Protein; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D009687:Nuclear Proteins / Q000235:genetics*; D015513:Oncogene Proteins / Q000235:genetics*; D011003:Ploidies; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016879:Salvage Therapy; D016896:Treatment Outcome; D014481:United States
chemical_list: C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins