title: Osteosarcoma in patients younger than 12 years old without metastases have similar prognosis as adolescent and young adults.
abstract: BACKGROUND
  Childhood cancer is relatively rare and tends to present specific age distribution, as a prognostic factor for some of these diseases. Information on how young age affects prognosis, response to chemotherapy, and local control options in children versus AYA with osteosarcoma (OST) is minimal.
  
  
  METHODS
  In order to identify the main differences in clinical pathologic features, surgical approaches and survival rates of primary high grade OST of the extremity between children (n = 156; <12 years old) and AYA (n = 397; 12-30 years old), the institutional database with 553 patients treated by BOTG studies over 15 years were reviewed.
  
  
  RESULTS
  There were no differences in metastases at diagnosis, tumor size, and grade of necrosis between the two age groups. The rate of amputation was 30% higher in the children group (P = 0.018). The rate of limb salvage surgery using reconstruction with allograft or autograft was 70% higher in the children group (P = 0.018) while endoprosthesis rate was 40% higher in the AYA group (P = 0.018). The log rank test revealed that survival is similar between the two age groups for non-metastatic patients (P = 0.424 for OS and P = 0.393 for EFS). Metastatic patients of both ages group had higher risk of dying compared to non-metastatic (HR 3.283 95% CI 2.581-4.177; P < 0.001). Children with metastases at diagnosis had less OS time (P = 0.049) and EFS time (P = 0.032) than adolescents.
  
  
  CONCLUSIONS
  Non-metastatic OST in preadolescent patients does not appear to be significantly different from those seen in AYA patients, but has local control challenges. Children presenting with metastases should be considered an ultra-high-risk group.
authors.affiliation: Institutode Oncologia Pediatrica/GRAACC-Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Sabrina Jeane Prates
authors.initials: SJ
authors.lastname: Eleutério
authors.affiliation: Institutode Oncologia Pediatrica/GRAACC-Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Andreza Almeida
authors.initials: AA
authors.lastname: Senerchia
authors.affiliation: Instituto da Crianca-Universidade de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Almeida
authors.affiliation: Hospital do Cancer A. C. Camargo, Sao Paulo, Brazil.
authors.forename: Cecilia Maria
authors.initials: CM
authors.lastname: Da Costa
authors.affiliation: Hospital do Cancer do Ceara, Ceara, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lustosa
authors.affiliation: Sociedade Pernambucana de Combate ao Cancer, Pernambuco, Brazil.
authors.forename: Luiz Mario
authors.initials: LM
authors.lastname: Calheiros
authors.affiliation: Sociedade de Oncologia da Bahia, Bahia, Brazil.
authors.forename: Jose Henrique Silva
authors.initials: JH
authors.lastname: Barreto
authors.affiliation: Hospital de Clınicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Algemir Lunardi
authors.initials: AL
authors.lastname: Brunetto
authors.affiliation: Institutode Oncologia Pediatrica/GRAACC-Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Carla Renata Pacheco Donato
authors.initials: CR
authors.lastname: Macedo
authors.affiliation: Institutode Oncologia Pediatrica/GRAACC-Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Antonio Sergio
authors.initials: AS
authors.lastname: Petrilli
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001859:Bone Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005121:Extremities / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D011379:Prognosis; D015996:Survival Rate; D055815:Young Adult
keywords: adolescent; amputation; chemotherapy; childhood bone cancer; children; osteosarcoma; young adult