title: Prognostic role of hypoxia-inducible factor-1 alpha expression in osteosarcoma: a meta-analysis.
abstract: BACKGROUND
  Hypoxia-inducible factor-1α (HIF-1α) plays an important role in tumor progression and metastasis. A number of studies have investigated the association of HIF-1α with prognosis and clinicopathological characteristics of osteosarcoma but yielded inconsistent results.
  
  
  METHODS
  Systematic computerized searches were performed in PubMed, Embase, and Web of Science databases for relevant original articles. The pooled hazard ratios (HRs) and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated to assess the prognostic value of HIF-1α expression. The standard mean difference was used to analyze the continuous variable.
  
  
  RESULTS
  Finally, nine studies comprising 486 patients were subjected to final analysis. Protein expression level of HIF-1α was found to be significantly related to overall survival (HR =3.0; 95% CI: 1.46-6.15), disease-free survival (HR =2.23; 95% CI: 1.26-3.92), pathologic grade (OR =21.33; 95% CI: 4.60-98.88), tumor stage (OR =10.29; 95% CI: 3.55-29.82), chemotherapy response (OR =9.68; 95% CI: 1.87-50.18), metastasis (OR =5.06; 95% CI: 2.87-8.92), and microvessel density (standard mean difference =2.83; 95% CI: 2.28-3.39).
  
  
  CONCLUSIONS
  This meta-analysis revealed that overexpression of HIF-1α is a predictive factor of poor outcomes for osteosarcoma. HIF-1α appeared to play an important role in prognostic evaluation and may be a potential target in antitumoral therapy.
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Hai-Yong
authors.initials: HY
authors.lastname: Ren
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China; The First Department of Orthopaedics, Hospital of Zhejiang General Corps of Armed Police Forces, Jiaxing, People's Republic of China.
authors.forename: Yin-Hua
authors.initials: YH
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Heng-Yuan
authors.initials: HY
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xie
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Sun
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhu
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Sheng-Dong
authors.initials: SD
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Zhao-Ming
authors.initials: ZM
authors.lastname: Ye
keywords: HIF-1α; meta-analysis; osteosarcoma; prognosis