title: Clinical application of gene expression profiling in breast cancer.
abstract: Breast cancer is a heterogeneous disease associated with variable clinical outcomes and response to therapy. Classic clinicopathologic factors associated with outcome include anatomic features associated with prognosis (eg, tumor size, number of positive regional lymph nodes) and biologic features associated with prognosis and/or predictive of response to specific therapies, usually by evaluating protein expression by immunohistochemistry (eg, estrogen and/or progesterone receptors) or amplification of a single gene (eg, HER2/neu). Gene expression profiling evaluating thousands of genes is now feasible, and has facilitated the development of multiparameter assays that may identify breast cancer subtypes associated with distinct clinical outcomes that were not previously recognized, or provide more accurate information about prognosis or response to specific therapies than may be provided by classic clinicopathologic features alone. Several multiparameter gene expression assays are commercially available, and additional assays are being developed that will facilitate more accurate therapeutic individualization.
authors.affiliation: Department of Medicine and Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, 1825 Eastchester Road, Bronx, NY 10461, USA. jsparano@montefiore.org
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sparano
authors.forename: Melissa
authors.initials: M
authors.lastname: Fazzari
authors.forename: Paraic A
authors.initials: PA
authors.lastname: Kenny
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor