Herceptin Metastatic Breast Cancer Treatment
December 1998 -- Herceptin (trastuzumab) is the newest drug for the management of metastatic breast cancer (breast cancer that has spread beyond the breast). It is a new type of drug and has a different mechanism of action than any other drug used to treat breast cancer.
Most cells in the body, including breast cancer cells, are dependent
their growth on growth factors, proteins that are made by cells in
and then circulate in the blood. The circulating growth factors bind
protein receptors on cells and stimulate them to grow. Approximately
of breast cancers overexpress (have higher than normal amounts of) a
receptor for an important growth factor called HER2 protein.
Herceptin is a
synthetic (man-made) antibody which binds and blocks the HER2 protein
breast cancer cells so that circulating growth factor cannot bind and
stimulate the breast cancer cells to grow. Herceptin is given as an