title: Prevalence and clinical impact of anaplasia in childhood rhabdomyosarcoma : a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group.
abstract: BACKGROUND
  Anapalsia is rare in childhood rhabdomyosarcoma and has not been included in the International Classification of Rhabdomyosarcoma (ICR). A recent review of cases from the Soft Tissue Sarcoma Committee of the Children's Oncology Group (COG) suggests that anaplasia might be more common than previously reported and may impact clinical outcome.
  
  
  METHODS
  The prevalence of anaplasia (focal or diffuse) was prospectively assessed in 546 eligible cases who were registered in an Intergroup Rhabdomyosarcoma Study Group (IRSG) or COG therapeutic trial from 1995 through 1998. The incidence of anaplasia in tumor samples and its impact in predicting clinical outcome was assessed.
  
  
  RESULTS
  Overall, 71 (13%) of all samples analyzed had anaplasia. Anaplasia was more common in patients with tumors in favorable sites and was less commonly observed in younger patients and in those with stage II, III, or clinical group III disease. Regardless of its distribution (focal or diffuse), on univariate analysis the presence of anaplasia negatively influenced the failure-free survival rate (63% vs 77% at 5 years) and overall survival (68% vs 82% at 5 years) rates in patients with embryonal rhabdomyosarcoma. This effect was most pronounced in children with intermediate-risk tumors. Anaplasia did not affect outcome in patients with alveolar tumors.
  
  
  CONCLUSIONS
  The incidence of anaplasia in patients with rhabdomyosarcoma is higher than previously described and may be of prognostic significance in children with intermediate-risk embryonal rhabdomyosarcoma.
authors.affiliation: Center for Childhood Cancer, Columbus, Ohio, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Qualman
authors.forename: James
authors.initials: J
authors.lastname: Lynch
authors.forename: Julia
authors.initials: J
authors.lastname: Bridge
authors.forename: David
authors.initials: D
authors.lastname: Parham
authors.forename: Lisa
authors.initials: L
authors.lastname: Teot
authors.forename: William
authors.initials: W
authors.lastname: Meyer
authors.forename: Alberto
authors.initials: A
authors.lastname: Pappo
mesh_terms: D000708:Anaplasia / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012208:Rhabdomyosarcoma / Q000473:pathology*; D018233:Rhabdomyosarcoma, Embryonal / Q000473:pathology; D012509:Sarcoma / Q000473:pathology*; D016019:Survival Analysis