title: Improved survival in osteosarcoma patients with atypical low vascularization.
abstract: BACKGROUND
  Osteosarcoma is considered a highly vascularized bone tumor with early metastatic dissemination through intratumoral blood vessels mostly into the lung. Novel targets for therapy such as tumor vascularization are highly warranted since little progress has been achieved in the last 30 years. However, proof of relevance for vascularization as a major prognostic parameter has been hampered by tumor heterogeneity, difficulty in detecting microvessels by immunohistochemistry, and small study cohorts. Most recently, we demonstrated that highly standardized whole-slide imaging could overcome these limitations (Kunz et al., PloS One 9(3):e90727, 2014). In this study, we applied this method to a multicenter cohort of 131 osteosarcoma patients to test osteosarcoma vascularization as a prognostic determinant.
  
  
  METHODS
  Computer-assisted whole-slide analysis, together with enzymatic epitope retrieval, was used for CD31-based microvessel quantification in 131 pretreatment formalin-fixed and paraffin-embedded biopsies from three bone tumor centers. Kaplan-Meier-estimated survival and chemoresponse were determined and multivariate analysis was performed. Conventional hot-spot-based microvessel density (MVD) determination was compared with whole-slide imaging.
  
  
  RESULTS
  We detected high estimated overall (p ≤ 0.008) and relapse-free (p ≤ 0.004) survival in 25 % of osteosarcoma patients with low osteosarcoma vascularization in contrast to other patient groups. Furthermore, all patients with low osteosarcoma vascularization showed a good response to neoadjuvant chemotherapy. Comparison of conventional MVD determination with whole-slide imaging suggests false high quantification or even exclusion of samples with low osteosarcoma vascularization due to difficult CD31 detection in previous studies.
  
  
  CONCLUSIONS
  Low intratumoral vascularization at the time of diagnosis is a strong predictor for prolonged survival and good response to neoadjuvant chemotherapy in osteosarcoma.
authors.affiliation: Department of Orthopedics and Traumatology, University Hospital Heidelberg, Heidelberg, Germany, Pierre.Kunz@gmx.de.
authors.forename: Pierre
authors.initials: P
authors.lastname: Kunz
authors.forename: Joerg
authors.initials: J
authors.lastname: Fellenberg
authors.forename: Linda
authors.initials: L
authors.lastname: Moskovszky
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Sápi
authors.forename: Tibor
authors.initials: T
authors.lastname: Krenacs
authors.forename: Isidro
authors.initials: I
authors.lastname: Machado
authors.forename: Johannes
authors.initials: J
authors.lastname: Poeschl
authors.forename: Burkhard
authors.initials: B
authors.lastname: Lehner
authors.forename: Miklos
authors.initials: M
authors.lastname: Szendrõi
authors.forename: Peter
authors.initials: P
authors.lastname: Ruef
authors.forename: Michael
authors.initials: M
authors.lastname: Bohlmann
authors.forename: Antonio Llombart
authors.initials: AL
authors.lastname: Bosch
authors.forename: Volker
authors.initials: V
authors.lastname: Ewerbeck
authors.forename: Ralf
authors.initials: R
authors.lastname: Kinscherf
authors.forename: Benedikt
authors.initials: B
authors.lastname: Fritzsching
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000098:blood supply* / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality*; D017024:Chemotherapy, Adjuvant; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000098:blood supply* / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism*; D011379:Prognosis; D055815:Young Adult
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1