An 8-gene qRT-PCR-based gene expression score that has prognostic value in early breast cancer

BMC Cancer. 2010 Jun 28;10:336. doi: 10.1186/1471-2407-10-336.

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.

MeSH terms

  • Breast Neoplasms / diagnosis
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / secondary
  • Breast Neoplasms / therapy
  • Databases, Genetic
  • Female
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation, Neoplastic*
  • Genetic Predisposition to Disease
  • Genetic Testing / methods*
  • Humans
  • Kaplan-Meier Estimate
  • Middle Aged
  • Neoplasm Staging
  • Paraffin Embedding
  • Polymerase Chain Reaction*
  • Predictive Value of Tests
  • Prognosis
  • Proportional Hazards Models
  • Reproducibility of Results
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors