How is classification of breast carcinoma done?

➢ This system, which is currently used mainly in the context of clinical research, divides breast cancers into four major types: • Luminal A. The majority are lower-grade ER-positive cancers that are HER2 negative • Luminal B. The majority are higher-grade ER-positive cancers that may be HER2 positive • HER2-enriched. The majority overexpress HER2 and do not express ER • Basal-like. The majority by gene expression profiling resemble basally located myoepithelial cells and are ER-negative, HER2-negative