title: Molecular classification of breast cancer: limitations and potential.
abstract: Reverse transcription polymerase chain reaction and DNA microarrays are increasingly used in the clinic and in clinical research as prognostic or predictive tests. Results from these tests led to novel risk stratification methods and to new molecular classification of breast cancer. Some of these tools already complement existing diagnostic tests and can aid medical decision making in some situations. Better understanding of the molecular classes of breast cancer, independent of their prognostic and predictive values, may also lead to new biological insights and eventually to better therapies that are directed toward particular molecular subsets. However, there is substantially less experience with these emerging technologies than with the more established methods, the accuracy of which is often overestimated. This review discusses some of the limitations and strengths of current gene expression-based molecular classification of breast cancer. To provide context for this discussion, we also briefly examine the performance of estrogen receptor immunohistochemistry, which represents an essential part of the routine diagnostic workup for all breast cancer patients.
authors.affiliation: D.Phil., University of Texas M.D. Anderson Cancer Center, Department of Breast Medical Oncology, Unit1354, PO Box 301439, Houston, Texas 77230-1439, USA. lpusztai@mdanderson.org
authors.forename: Lajos
authors.initials: L
authors.lastname: Pusztai
authors.forename: Chafika
authors.initials: C
authors.lastname: Mazouni
authors.forename: Keith
authors.initials: K
authors.lastname: Anderson
authors.forename: Yun
authors.initials: Y
authors.lastname: Wu
authors.forename: W Fraser
authors.initials: WF
authors.lastname: Symmans
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D001943:Breast Neoplasms / Q000145:classification* / Q000235:genetics*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008967:Molecular Biology / Q000145:classification*; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D011960:Receptors, Estrogen; D013673:Technology Assessment, Biomedical / Q000592:standards / Q000639:trends
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen