title: The limited screening value of insulin-like growth factor-I as a marker for alterations in body composition in very long-term adult survivors of childhood cancer.
abstract: BACKGROUND
  The clinical relevance of low IGF-I levels, caused by cranial radiotherapy, in adult childhood cancer survivors has not been studied extensively. We evaluated whether IGF-I is a useful marker for altered body composition and growth hormone deficiency (GHD) in this group.
  
  
  METHODS
  We analyzed retrospective data from 610 adult childhood cancer survivors, retrieved from the late effects clinic. Median age at diagnosis was 6 years (interquartile range 3-11) and follow-up time was 18 years (13-24). We assessed IGF-I standard deviation scores (SDS), anthropometrical measures, growth hormone stimulation tests in patients with clinical signs of GHD, and measures of body composition (assessed by dual X-ray absorptiometry, Lunar Prodigy).
  
  
  RESULTS
  In 58 cranially irradiated acute leukemia survivors (25 Gy (24-25)) and 56 locally irradiated brain tumor survivors (42 Gy (35-54)) we found significantly lower IGF-I SDS (P < 0.001), lower height SDS (P < 0.001), higher body mass index (P = 0.01), higher waist-hip ratio (WHR; P = 0.001), higher total fat percentage SDS (P < 0.001), and lower lean body mass SDS (P < 0.001), as compared to 452 not cranially irradiated survivors. IGF-I showed a weak inverse correlation with BMI (r = -0.12, P = 0.04), WHR (r = -0.15, P = 0.01), total fat percentage (r = - 0.14, P = 0.02), and a positive correlation with lean body mass (r = 0.15, P = 0.01). In patients with low IGF-I levels, IGF-I did not significantly differ between subjects with and without GHD as determined by GH-stimulation testing (P = 0.39).
  
  
  CONCLUSIONS
  This study shows that IGF-I has limited value as a marker for alterations in body composition in adult childhood cancer survivors.
authors.affiliation: Department of Pediatric Oncology/Hematology, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands. k.blijdorp@erasmusmc.nl
authors.forename: Karin
authors.initials: K
authors.lastname: Blijdorp
authors.forename: Marry
authors.initials: M
authors.lastname: van den Heuvel-Eibrink
authors.forename: Rob
authors.initials: R
authors.lastname: Pieters
authors.forename: Annemieke
authors.initials: A
authors.lastname: Boot
authors.forename: Johanna
authors.initials: J
authors.lastname: Sluimer
authors.forename: Aart-Jan
authors.initials: AJ
authors.lastname: van der Lelij
authors.forename: Sebastian
authors.initials: S
authors.lastname: Neggers
mesh_terms: D050154:Adiposity; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001823:Body Composition / Q000528:radiation effects; D001827:Body Height / Q000528:radiation effects; D015992:Body Mass Index; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002648:Child; D016371:Cranial Irradiation; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007938:Leukemia / Q000532:radiotherapy*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000532:radiotherapy; D017741:Survivors; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I