title: Insulin-like growth factor type 1 (IGF-1) and IGF binding protein-3 in patients with Ewing sarcoma family of tumors.
abstract: BACKGROUND
  Ewing sarcoma family of tumors (ESFTs) are the second most common bone tumor, that most often affects persons ages 3-40 years. The ESFTs rely on signaling through the insulin-like growth factor-1 receptor (IGF-1R) for growth and transformation. The current studies were performed to determine the levels of IGF-1 and IGF binding protein-3 (IGFBP-3) in patients with ESFT. The authors then performed an exploratory analysis to evaluate whether IGF parameters could differentiate event free or overall survival in ESFT patients.
  
  
  METHODS
  The authors measured serum levels of IGF-1 and IGFBP-3 by using a radioimmunoassay from 111 patients with ESFT with a median follow-up of 13 years from diagnosis.
  
  
  RESULTS
  The IGF-1 levels were lower among patients with metastatic disease to the bones or the bone marrow compared with patients without metastasis to these sites (p2 = 0.021 and 0.0038, respectively). IGFBP-3 is known to sequester IGF-1; the ratios of IGFBP-3 to IGF-1 were evaluated. Patients with metastatic disease to any site had higher IGFBP-3 to IGF-1 ratios than patients with localized disease (p2 = 0.0067). There was a trend toward increased survival in patients with localized disease who had high IGFBP-3 to IGF-1 levels. Metastatic patients showed a similar trend.
  
  
  CONCLUSIONS
  Levels of IGF-1 and IGFBP-3 in ESFT patients can identify patients with the most widespread disease. The IGFBP-3 to IGF-1 ratio in patients with either localized or metastatic disease identified patients with a trend toward increased survival. Further prospective evaluation with higher patient numbers might show a prognostic role for the IGFBP-3 to IGF-1 ratio in patients with ESFT.
authors.affiliation: Department of Pediatrics, University of Maryland, Baltimore, Maryland, USA. toretsky@helix.nih.gov
authors.forename: J A
authors.initials: JA
authors.lastname: Toretsky
authors.forename: S M
authors.initials: SM
authors.lastname: Steinberg
authors.forename: M
authors.initials: M
authors.lastname: Thakar
authors.forename: D
authors.initials: D
authors.lastname: Counts
authors.forename: B
authors.initials: B
authors.lastname: Pironis
authors.forename: C
authors.initials: C
authors.lastname: Parente
authors.forename: A
authors.initials: A
authors.lastname: Eskenazi
authors.forename: L
authors.initials: L
authors.lastname: Helman
authors.forename: L H
authors.initials: LH
authors.lastname: Wexler
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D001859:Bone Neoplasms / Q000097:blood* / Q000401:mortality; D019992:Databases as Topic; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D011379:Prognosis; D012512:Sarcoma, Ewing / Q000097:blood* / Q000401:mortality; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I