What is HER2-positive breast cancer?

HER2-positive breast cancer refers to a subtype of breast cancer characterized by the overexpression of the HER2 (human epidermal growth factor receptor 2) protein. This protein is part of a family of growth factor receptors and is involved in the signaling pathways that promote cell growth and division. When breast cancer cells have an abundance of HER2, it typically indicates a more aggressive form of cancer that can grow and spread more quickly than other types of breast cancer.

The diagnosis of HER2-positive breast cancer is determined through specific tests like immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). These tests assess the presence and amount of HER2 protein in cancer cells. Understanding this characteristic is crucial for guiding treatment options, as HER2-positive cancers often respond well to targeted therapies, such as trastuzumab (Herceptin) and other HER2 inhibitors, which can significantly improve patient outcomes.

In contrast, the other options do not accurately describe HER2-positive breast cancer. It is not specifically a slow-growing type, nor is it defined by hormone receptor negativity; HER2-positive tumors can coexist with hormone receptor-positive status as well. Additionally, HER2-positive breast cancer can occur in women of all ages, debunking