Harvard classification system

The Harvard classification system is a way doctors categorize breast cancers based on the presence of hormone receptors and other proteins. It mainly looks at whether the cancer cells have estrogen receptors (ER), progesterone receptors (PR), and the HER2 protein. These markers help determine how the cancer might grow and respond to treatments. The system divides breast cancers into groups like hormone receptor-positive, HER2-positive, and triple-negative (lacking all three). This classification guides doctors in selecting the most effective therapies and helps predict the cancer’s likely behavior.