title: YY1 overexpression is associated with poor prognosis and metastasis-free survival in patients suffering osteosarcoma.
abstract: BACKGROUND
  The polycomb transcription factor Yin Yang 1 (YY1) overexpression can be causally implicated in experimental tumor growth and metastasization. To date, there is no clinical evidence of YY1 involvement in outcome of patients with osteosarcoma. Prognosis of osteosarcoma is still severe and only few patients survive beyond five years. We performed a prospective immunohistochemistry analysis to correlate YY1 immunostaining with metastatic development and survival in a selected homogeneous group of patients with osteosarcoma.
  
  
  METHODS
  We studied 41 patients suffering from osteosarcoma (stage II-IVa). Multivariate analysis was performed using Cox proportional hazard regression to evaluate the correlation between YY1 expression and both metastasis development and mortality.
  
  
  RESULTS
  YY1 protein is not usually present in normal bone; in contrast, a high number of patients (61%) showed a high score of YY1 positive cells (51-100%) and 39% had a low score (10-50% positive cells). No statistical difference was found in histology, anatomic sites, or response to chemotherapy between the two degrees of YY1 expression. Cox regression analysis demonstrated that the highest score of YY1 expression was predictive of both low metastasis-free survival (HR = 4.690, 95%CI = 1.079-20.396; p = 0.039) and poor overall survival (HR = 8.353, 95%CI = 1.863-37.451 p = 0.006) regardless of the effects of covariates such as age, gender, histology and chemonecrosis.
  
  
  CONCLUSIONS
  Overexpression of YY1 in primary site of osteosarcoma is associated with the occurrence of metastasis and poor clinical outcome.
authors: Department of General Pathology, Division of Clinical Pathology and U.O.C. Immunohematology, Second University of Naples, 80138 Naples, Italy. filomena.denigris@unina2.it
authors: Filomena
authors: F
authors: de Nigris
authors: Licciana
authors: L
authors: Zanella
authors: Francesco
authors: F
authors: Cacciatore
authors: Anna
authors: A
authors: De Chiara
authors: Flavio
authors: F
authors: Fazioli
authors: Gennaro
authors: G
authors: Chiappetta
authors: Gaetano
authors: G
authors: Apice
authors: Teresa
authors: T
authors: Infante
authors: Mario
authors: M
authors: Monaco
authors: Raffaele
authors: R
authors: Rossiello
authors: Gaetano
authors: G
authors: De Rosa
authors: Marco
authors: M
authors: Alberghini
authors: Claudio
authors: C
authors: Napoli
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001859:Bone Neoplasms / Q000378:metabolism* / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009363:Neoplasm Proteins / Q000378:metabolism*; D012516:Osteosarcoma / Q000378:metabolism* / Q000556:secondary / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D050986:YY1 Transcription Factor / Q000378:metabolism*
chemical_list: D009363:Neoplasm Proteins; D050986:YY1 Transcription Factor