title: Gene expression-based prognostic and predictive markers for breast cancer: a primer for practicing pathologists.
abstract: BACKGROUND
  Gene expression-based prognostic assays for breast cancer are now available as commercial reference laboratory tests covered by insurance.
  
  
  OBJECTIVE
  To provide practicing pathologists with information about the nature of these assays, differences among them, and their use by clinical oncologists in the management of patients diagnosed with breast cancer.
  
  
  METHODS
  Review of literature and unpublished data from the National Surgical Adjuvant Breast and Bowel Project. This review focused on a general conceptual description of the technology behind these assays and differences among them to aid understanding by pathologists in practice.
  
  
  CONCLUSIONS
  While these assays are clinically useful, they are still evolving. The future development of gene expression-based markers will need to be more clinical-context-specific to be clinically useful.
authors.affiliation: Division of Pathology, National Surgical Adjuvant Breast and Bowel Project Foundation, Pittsburgh, Pennsylvania, USA.
authors.forename: Chungyeul
authors.initials: C
authors.lastname: Kim
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Taniyama
authors.forename: Soonmyung
authors.initials: S
authors.lastname: Paik
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D010336:Pathology / Q000379:methods*; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor