Targeted therapies can attack specific breast cancer cells without harming normal cells. They are drugs that block the growth of breast cancer cells in specific ways.
The best known targeted therapies are the hormone therapies targeting the oestrogen receptor. HER2 therapies (Herceptin, Perjeta, Kadcyla and Tykerb) that block the action of HER2 receptors on cells are the best known newer targeted therapies. Breast cancers that are HER2-positive have excessive numbers of HER2 receptors on the surface of the cancer cells. These receptors allow growth factors to stimulate the growth of the cancer cells. Treatments that block the HER2 receptors prevent this growth stimulation, in turn controlling the cancer.
New targeted therapies that block other pathways within cancer cells are currently in development. These targeted therapies are sometimes called biological therapies.
Herceptin may cause heart problems in some women, which can be detected with heart tests before symptoms occur. Your medical oncologist will discuss any possible benefits and drawbacks of taking Herceptin as part of your treatment.
The page on managing symptoms and side effects contains advice on dealing with certain side effects from various forms of treatment, including targeted therapies.