title: Elevated tumor and serum levels of the hypoxia-associated protein osteopontin are associated with prognosis for soft tissue sarcoma patients.
abstract: BACKGROUND
  Osteopontin (OPN) overexpression is correlated with a poor prognosis for tumor patients. However, only a few studies investigated the prognostic impact of expression of OPN in soft tissue sarcomas (STS) yet.
  
  
  METHODS
  This study is based on tumor and serum samples from 93 adult STS patients. We investigated OPN protein levels in serum (n = 86) and tumor tissue (n = 80) by ELISA and OPN mRNA levels in tumor tissue (n = 68) by quantitative real-time PCR.
  
  
  RESULTS
  No correlation was found between OPN levels in serum and tumor tissue. Moreover, an elevated OPN protein level in the serum was significantly associated with clinical parameters such as higher stage (p = 0.004), higher grade (p = 0.003), subtype (p = 0.002) and larger tumor size (p = 0.03). OPN protein levels in the tumor tissue were associated with higher stage (p = 0.06), higher grade (p = 0.003), subtype (p = 0.07) and an increased rate of relapse (p = 0.02). In addition, using a Cox's proportional hazards regression model, we found that an elevated OPN protein level in the serum and tumor tissue extracts is a significant negative prognostic factor for patients with STS. The relative risks of tumor-related death were 2.2 (p < 0.05) and 3.7 (p = 0.01), respectively.
  
  
  CONCLUSIONS
  Our data suggest OPN protein in serum as well as in tumor tissue extracts is an important prognostic factor for soft tissue sarcoma patients.
authors.affiliation: Department of Radiotherapy, Martin-Luther-University Halle-Wittenberg, Halle, Germany. matthias.bache@medizin.uni-halle.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Bache
authors.forename: Matthias
authors.initials: M
authors.lastname: Kappler
authors.forename: Henri
authors.initials: H
authors.lastname: Wichmann
authors.forename: Swetlana
authors.initials: S
authors.lastname: Rot
authors.forename: Antje
authors.initials: A
authors.lastname: Hahnel
authors.forename: Thomas
authors.initials: T
authors.lastname: Greither
authors.forename: Harun M
authors.initials: HM
authors.lastname: Said
authors.forename: Matthias
authors.initials: M
authors.lastname: Kotzsch
authors.forename: Peter
authors.initials: P
authors.lastname: Würl
authors.forename: Helge
authors.initials: H
authors.lastname: Taubert
authors.forename: Dirk
authors.initials: D
authors.lastname: Vordermark
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood / Q000378:metabolism*; D015687:Cell Hypoxia / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D053495:Osteopontin / Q000097:blood / Q000378:metabolism*; D012509:Sarcoma / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D053495:Osteopontin