title: Non-metastatic osteosarcoma of the extremities in children aged 5 years or younger.
abstract: BACKGROUND
  The occurrence of high-grade osteosarcoma is rare in children aged 5 years or younger and only limited series or case reports have been described.
  
  
  METHODS
  The records of patients aged 5 years or younger with non-metastatic high-grade osteosarcoma of the extremities treated with surgery and adjuvant or neo-adjuvant chemotherapy at Rizzoli Institute between 1972 and 1999 were retrospectively evaluated in relation to gender, primary tumor site, histological subtype, surgical treatment, chemotherapy-induced tumor necrosis, 5- and 10-year event-free survival (EFS), and rate of local recurrence. Data were compared to patients aged 6-40 years entered with the same diagnosis and over the same time interval.
  
  
  RESULTS
  Data from 20 patients were collected. Comparing these data with those from 1,106 patients 6-40 years of age only two main differences resulted: the younger group showed a higher rate for fibroblastic subtype (P < 0.01) and for amputation surgery (P < 0.01). Among the two groups, no statistical difference was observed for the 5-year EFS (60% vs. 53.8%; P = 0.6) and 10-year EFS (60% vs. 52.1%; P = 0.5). The rate of local recurrence was 5.0% and 5.4%.
  
  
  CONCLUSIONS
  These findings suggest that in non-metastatic osteosarcoma of the extremities outcome and clinical characteristics are similar among children 5 years of age or younger and older patients. However, in the younger group we have observed a significant higher rate of fibroblastic subtype as well as a significant higher rate of mutilating surgery. Pediatr Blood Cancer.
authors.affiliation: Department of Chemotherapy, Istituto Ortopedico Rizzoli, Bologna, Italy. massimo.abate@ior.it
authors.forename: Massimo Eraldo
authors.initials: ME
authors.lastname: Abate
authors.forename: Alessandra
authors.initials: A
authors.lastname: Longhi
authors.forename: Stefano
authors.initials: S
authors.lastname: Galletti
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferrari
authors.forename: Gaetano
authors.initials: G
authors.lastname: Bacci
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001859:Bone Neoplasms / Q000453:epidemiology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D005121:Extremities; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012516:Osteosarcoma / Q000453:epidemiology* / Q000628:therapy