, also an antiestrogenic drug, is also being tested for effectiveness. Raloxifene decreased the risk of estrogen receptorpositive breast cancer by 90% (Cummings). New approaches involving reprogramming of the tumor cell genes and targeting of the blood vessels that feed tumors provide hope for more effective and less toxic therapy. One of the newest forms of breast cancer treatments is a monoclonal antibody called trastuzumab and marketed under the brand name Herceptin. This drug targets cells that overproduce HER-2, a protein implicated in about one-third of all breast cancer cases. Although still under study, Herceptin, helps make chemotherapy more effective by shrinking tumors and slowing the progression of the disease. An advisory committee of the FDA has recommended that Herceptin be approved for use; it will be most effective in a type of breast cancer that afflicts about 30 percent of breast cancer patients. Herceptin reverses the process, by starting with a discovery about the basic genetics of cancer, and then designing a drug to counteract the abnormality. The key in this case is a gene called HER-2/neu. The gene carries instructions for a protein that sits on the surface of a cell and receives signals from "growth factor" molecules. Thus the HER-2/neu gene and protein play a key role in the fundamental threat of cancer: tumor cells that grow out of control. Meanwhile, researchers are continuing to study the drug to see if it can improve the prognosis of women with earlier stage breast cancers. Experts point out that although Herceptin is unlikely to cure women with metastatic breast cancer, the results of the trials so far are a clear sign of progress. Normal cells carry two copies of HER-2/neu, and have a small number of the HER-2/neu protein receptors on their surfaces. But researchers found that some cancers have extra copies of the gene and an overabundance of cell surface receptors. The abnormality is not inherited; r...
