Biologic response modifiers:

These drugs bind with certain proteins on breast cancer cells, preventing their growth. The drug Herceptin (generic name, trastuzumab) is a monoclonal antibody that attaches itself to HER2 (also written HER2/neu), a protein found on breast cancer cells. Approximately 30% of breast cancer patients have extra copies of the HER2 protein, which can signal more aggressive cancers. Herceptin binds to HER2 receptors on breast cancer cells, preventing them from growing and dividing. Herceptin is only indicated for breast cancer patients who overexpress the HER2 protein. Patients should be tested for HER2 expression to determine whether Herceptin is a viable treatment option. Other hormonal therapies: Hormone therapies are used to treat breast cancers that are dependent on estrogen for survival. In addition to SERMs and aromatase inhibitors, there are several other hormonal therapies used to treat breast cancer. For example, the drug Zoladex (generic name, goserelin acetate) is a synthetic form of the body’s lutenizing hormone-releasing hormone (LHRH). Zoladex blocks the release of estrogen in breast cancer patients (and testosterone in prostate cancer patients), preventing breast and prostate cancer cells from growing.
Another hormone therapy, Faslodex (generic name, fulvestrant), appears to be effective for women who have become resistant to tamoxifen, according to recent studies. Instead of binding to estrogen receptors in breast cancer cells like tamoxifen, Faslodex destroys estrogen receptors in cancer cells.