title: Predictors of bony morbidity in children with acute lymphoblastic leukemia.
abstract: BACKGROUND
  To evaluate the relationship between lumbar spine (LS) bone mineral density (BMD) and patient-, disease-, and therapy-related variables, and to define the risk-factors for fractures in children receiving therapy on Dana-Farber Cancer Institute acute lymphoblastic leukemia (ALL) protocols.
  
  
  METHODS
  Children (≤18 years) diagnosed with ALL during the period 1995-2006, who are in first clinical remission, were included (n = 124). Dual-energy X-ray absorptiometry provided LS-BMD at diagnosis (n = 46) and during continuation therapy. LS-BMD was expressed as Z scores based on local population norms. Regression analyses evaluated the risk of osteopenia (Z-score -1.01 to -1.99, osteoporosis (Z-score -2.00 or less) and fractures.
  
  
  RESULTS
  At diagnosis, 14 0f 46 (30%) patients had osteopenia and 5 (11%) had osteoporosis; whereas, during continuation therapy, 47 of 124 (39.5%) patients had osteopenia, and 10 (8%) had osteoporosis. LS-BMD at diagnosis had a positive linear relationship with LS-BMD during continuation therapy (Pearson correlation coefficient 0.619, P < 0.0001). Multivariable analyses identified age ≥10 years and LS-BMD at diagnosis as independent predictors of LS-BMD during continuation therapy. Twenty-three (18.5%) patients developed fractures. Dexamethasone therapy (OR 3.4, 95% CI 1.31, 7.52, P = 0.01) and lower LS-BMD during the continuation therapy (OR 1.8, 95% CI 1.2, 2.8, P = 0.01) were independent predictors of fracture.
  
  
  CONCLUSIONS
  Older age and lower LS-BMD at diagnosis are predictors of lower LS-BMD during continuation therapy. Dexamethasone and lower LS-BMD during continuation therapy are associated with fractures. Using these variables it is feasible to develop a predictor model to define the risk of bony morbidity in children receiving ALL therapy.
authors.affiliation: Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Meera S
authors.initials: MS
authors.lastname: Rayar
authors.forename: Trishana
authors.initials: T
authors.lastname: Nayiager
authors.forename: Colin E
authors.initials: CE
authors.lastname: Webber
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Barr
authors.forename: Uma H
authors.initials: UH
authors.lastname: Athale
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects; D015519:Bone Density / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D003907:Dexamethasone / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008954:Models, Biological; D010024:Osteoporosis / Q000139:chemically induced / Q000401:mortality; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000401:mortality; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D016103:Spinal Fractures / Q000139:chemically induced / Q000401:mortality
chemical_list: D003907:Dexamethasone