title: Survival rate and prognostic factors of conventional osteosarcoma in Northern Thailand: A series from Chiang Mai University Hospital.
abstract: BACKGROUND
  Osteosarcoma is a common and aggressive primary malignant bone tumor occurring in children and adolescents. It is one of the most aggressive human cancers and the most common cause of cancer-associated limb loss. As treatment in Thailand has produced a lower survival rate than in developed countries; therefore, this study identified survival rate and the poor prognostic factors of osteosarcoma in Northern Thailand.
  
  
  METHODS
  The retrospective cases of osteosarcoma, diagnosis between 1 January 1996 and 31 December 2013, were evaluated. Five and ten year overall survival rates were analyzed using time-to-event analysis. Potential prognostic factors were identified by multivariate regression analysis.
  
  
  RESULTS
  There were 208 newly diagnosed osteosarcomas during that period, and 144 cases met the criteria for analysis. The majority of the osteosarcoma cases (78.5%) were aged 0-24 years. The overall 5- and 10-year survival rates were 37.9% and 33.6%, respectively. Presence of metastasis at initial examination, delayed and against treatment co-operation, and axial skeletal location were identified as independent prognostic factors for survival, with hazard ratios of 4.3, 2.5 and 3.8, and 3.1, respectively.
  
  
  CONCLUSIONS
  This osteosarcoma cohort had a relatively poor overall survival rate. The prognostic factors identified would play a critical role in modifying survival rates of osteosarcoma patients; as rapid disease recognition, a better treatment counselling, as well as improving of chemotherapeutic regimens were found to be important in improving the overall survival rate in Thailand.
authors.affiliation: Department of Orthopedics, Faculty of Medicine, Chiang Mai University, Thailand; Excellence Center in Osteology Research and Training Center (ORTC), Chiang Mai University, Thailand.
authors.forename: Dumnoensun
authors.initials: D
authors.lastname: Pruksakorn
authors.affiliation: Department of Orthopedics, Faculty of Medicine, Chiang Mai University, Thailand.
authors.forename: Areerak
authors.initials: A
authors.lastname: Phanphaisarn
authors.affiliation: Department of Orthopedics, Faculty of Medicine, Chiang Mai University, Thailand; Orthopedic Surgery Division, Bangkok Hospital Chiang Mai, Thailand.
authors.forename: Olarn
authors.initials: O
authors.lastname: Arpornchayanon
authors.affiliation: Department of Orthopedics, Faculty of Medicine, Chiang Mai University, Thailand.
authors.forename: Nantawat
authors.initials: N
authors.lastname: Uttamo
authors.affiliation: Department of Orthopedics, Faculty of Medicine, Chiang Mai University, Thailand.
authors.forename: Taninnit
authors.initials: T
authors.lastname: Leerapun
authors.affiliation: Department of Pathology, Faculty of Medicine, Chiang Mai University, 50200, Thailand. Electronic address: jsettakorn@gmail.com.
authors.forename: Jongkolnee
authors.initials: J
authors.lastname: Settakorn
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000401:mortality* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D012516:Osteosarcoma / Q000401:mortality* / Q000473:pathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
keywords: Metastasis; Osteosarcoma; Patient compliance; Prognosis; Thailand