HER2statusin

HER2 status refers to the testing of a tumor for the presence and level of the HER2 protein. HER2, which stands for Human Epidermal growth factor Receptor 2, is a gene that plays a role in cell growth and division. In some types of cancer, particularly breast cancer, the HER2 gene can be amplified or mutated, leading to an overproduction of the HER2 protein. This overexpression can cause cancer cells to grow and divide more rapidly.

HER2 status is determined through laboratory tests performed on a sample of the tumor. The most common tests are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). IHC measures the amount of HER2 protein on the surface of cancer cells, while FISH detects the number of HER2 gene copies. A positive HER2 status indicates that the cancer cells have an abnormal amount of HER2 protein or gene copies.

Knowing a patient's HER2 status is crucial for treatment planning, especially in breast cancer. Cancers that are HER2-positive can be treated with targeted therapy drugs, such as trastuzumab, pertuzumab, and ado-trastuzumab emtansine. These medications specifically target the HER2 protein, inhibiting cancer cell growth and improving treatment outcomes. Conversely, HER2-negative cancers are not typically responsive to these targeted therapies. Therefore, accurate HER2 testing is a vital step in personalizing cancer treatment.