Molecular Stratification of Triple-Negative Breast Cancers, Oncologist

advisory role: CALGB Breast Committee; Ownership interest: University Genomics. The content of this article has been reviewed by independent peer reviewers to ensure that it is balanced, objective, and free from commercial bias. No financial relationships relevant to the content of this article have been disclosed by the authors or independent peer reviewers. Research focused on the analysis and classification of breast tumors, primarily using DNA microarrays and patterns of gene expression, has resulted in distinct tu-mor subtypes. Although no knowledge of patient sur-vival or outcomes was used to derive these gene descriptions, these different classes based upon patterns of gene expression have important prognostic implica-tions. Predictive markers in estrogen receptor–negative and triple-negative disease will be particularly impor-tant because in the absence of therapy, these tumor sub-types tend to have a poor prognosis. In addition, the claudin-low subgroup has been found to be common within the triple-negative cancers and may have further prognostic and therapeutic implications. Patients with tri-ple-negative breast cancer do benefit from chemotherapy, but better treatment options are needed that are less toxic, reduce the risk of disease progression, and are more tar-geted to this patient population. Potential treatments in-clude poly (ADP-ribose) polymerase inhibitors, and therapies that target cancer stem cells could also have an important impact in these patients. This article will focus on the molecular stratification of triple-negative breast cancers and the therapeutic implications of these classifi-cations. The Oncologist 2011;16(suppl 1):61–7