Assays and Intrinsic Subtypes of Breast Cancer

Lisa A. Carey, MD, Professor of Medicine, University of North Carolina at Chapel Hill, discusses assays and intrinsic subtypes of breast cancer.

The six intrinsic subtypes of breast cancer are luminal A, luminal B, HER2-enriched, basal-like, normal breast, and claudin-low. Though these subtypes are prognostic, Carey says, the way they inform treatment is a work in progress.

Several assays exist specifically to prognosticate the disease such as the 70-gene MammaPrint and the Oncotype DX Recurrence Score. A number of assays exist, though Carey notes that nothing is valid for ER-, HER2+ disease.

Clinical Pearls

The question remains as to how assays will be assessed regarding the information they give off and how pathways can be put together within a subtype, Carey says. In the future, physicians and researchers will molecularly characterize tumors and then use assays to get better information regarding treatment.

• There are six intrinsic subtypes of breast cancer: luminal A, luminal B, HER2-enriched, basal-like, normal breast, and claudin-low
• The way intrinsic subtypes inform treatment is a work in progress
• Carey believes that, in the future, physicians and researchers will molecularly characterize tumors and then use assays to get better information regarding treatment