title: An 8-gene qRT-PCR-based gene expression score that has prognostic value in early breast cancer.
abstract: BACKGROUND
  Gene expression profiling may improve prognostic accuracy in patients with early breast cancer. Our objective was to demonstrate that it is possible to develop a simple molecular signature to predict distant relapse.
  
  
  METHODS
  We included 153 patients with stage I-II hormonal receptor-positive breast cancer. RNA was isolated from formalin-fixed paraffin-embedded samples and qRT-PCR amplification of 83 genes was performed with gene expression assays. The genes we analyzed were those included in the 70-Gene Signature, the Recurrence Score and the Two-Gene Index. The association among gene expression, clinical variables and distant metastasis-free survival was analyzed using Cox regression models.
  
  
  RESULTS
  An 8-gene prognostic score was defined. Distant metastasis-free survival at 5 years was 97% for patients defined as low-risk by the prognostic score versus 60% for patients defined as high-risk. The 8-gene score remained a significant factor in multivariate analysis and its performance was similar to that of two validated gene profiles: the 70-Gene Signature and the Recurrence Score. The validity of the signature was verified in independent cohorts obtained from the GEO database.
  
  
  CONCLUSIONS
  This study identifies a simple gene expression score that complements histopathological prognostic factors in breast cancer, and can be determined in paraffin-embedded samples.
authors.affiliation: Unidad de Investigación, Instituto de Investigación Sanitaria IdIPAZ, Hospital Universitario La Paz, Paseo de la Castellana 261, Madrid 28046, Spain.
authors.forename: Iker
authors.initials: I
authors.lastname: Sánchez-Navarro
authors.forename: Angelo
authors.initials: A
authors.lastname: Gámez-Pozo
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pinto
authors.forename: David
authors.initials: D
authors.lastname: Hardisson
authors.forename: Rosario
authors.initials: R
authors.lastname: Madero
authors.forename: Rocío
authors.initials: R
authors.lastname: López
authors.forename: Belén
authors.initials: B
authors.lastname: San José
authors.forename: Pilar
authors.initials: P
authors.lastname: Zamora
authors.forename: Andrés
authors.initials: A
authors.lastname: Redondo
authors.forename: Jaime
authors.initials: J
authors.lastname: Feliu
authors.forename: Paloma
authors.initials: P
authors.lastname: Cejas
authors.forename: Manuel
authors.initials: M
authors.lastname: González Barón
authors.forename: Juan
authors.initials: J
authors.lastname: Angel Fresno Vara
authors.forename: Enrique
authors.initials: E
authors.lastname: Espinosa
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000556:secondary / Q000628:therapy; D030541:Databases, Genetic; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009367:Neoplasm Staging; D016612:Paraffin Embedding; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors