title: Bone mineral density among long-term survivors of childhood acute lymphoblastic leukemia: results from the St. Jude Lifetime Cohort Study.
abstract: BACKGROUND
  The prevalence of low bone mineral density (BMD) in adult survivors of childhood acute lymphoblastic leukemia (ALL), and the degree of recovery or decline, are not well elucidated.
  
  
  METHODS
  Study subjects (age ≥ 18 years and ≥10 years post-diagnosis) participated in an institutional follow-up protocol and risk-based clinical evaluation based on Children's Oncology Group guidelines. Trabecular volumetric BMD was ascertained using quantitative computed tomography, reported as age- and sex-specific Z-scores.
  
  
  RESULTS
  At median age 31 years, 5.7% of 845 subjects had a BMD Z-score of ≤-2 and 23.8% had a Z-score of -1 to -2. Cranial radiation dose of ≥24 Gy, but not cumulative methotrexate or prednisone equivalence doses, was associated with a twofold elevated risk of a BMD Z-score of ≤-1. The cranial radiation effect was stronger in females than in males. In a subset of 400 subjects, 67% of those who previously had a BMD Z-score of ≤-2 improved by one or more categories a median of 8.5 years later.
  
  
  CONCLUSIONS
  Very low BMD was relatively uncommon in this sample of adult survivors of childhood ALL, and BMD Z-scores tended to improve from adolescence to young adulthood. High-dose cranial or craniospinal radiation exposure was the primary predictor of suboptimal BMD in our study. Given that cranial radiation treatment for childhood ALL is used far more sparingly now than in earlier treatment eras, concerns about persistently low BMD among most current childhood ALL patients may be unwarranted.
authors.affiliation: Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, Memphis, Tennessee; School of Public Health, University of Memphis, Memphis, Tennessee.
authors.forename: J G
authors.initials: JG
authors.lastname: Gurney
authors.forename: S C
authors.initials: SC
authors.lastname: Kaste
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: D K
authors.initials: DK
authors.lastname: Srivastava
authors.forename: W
authors.initials: W
authors.lastname: Chemaitilly
authors.forename: K K
authors.initials: KK
authors.lastname: Ness
authors.forename: J Q
authors.initials: JQ
authors.lastname: Lanctot
authors.forename: R P
authors.initials: RP
authors.lastname: Ojha
authors.forename: K A
authors.initials: KA
authors.lastname: Nottage
authors.forename: C L
authors.initials: CL
authors.lastname: Wilson
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: L L
authors.initials: LL
authors.lastname: Robison
authors.forename: M M
authors.initials: MM
authors.lastname: Hudson
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology* / Q000532:radiotherapy*; D012189:Retrospective Studies; D012737:Sex Factors; D017741:Survivors
keywords: cranial radiation; epidemiology; late effects; osteopenia; osteoporosis