Targeted cancer therapies are drugs or other substances that block the growth and spread of cancer. Targeted therapies select specific cells to attack, leaving healthy cells alone. They are often used with other types of therapy suited to specific types of breast cancer. Targeted therapies are a cornerstone of precision medicine, a form of medicine that uses information about a person’s genes and proteins to prevent, diagnose, and treat disease.
Most targeted therapies focus on HER2-positive breast cancer. About 25% of cancers express the Her 2 protein gene. HER2 positive breast cancers make too much of the HER2 protein, which accepts signals that tell the cancer to keep dividing and spreading. Herceptin and Perjeta are drugs that attach themselves to the HER2 receptors on the surface of breast cancer cells and block them from receiving growth signals; they can also alert the immune system to destroy cancer cells onto which it is attached.
Other targeted therapies are used in women with late stage or metastatic breast cancer.
