FDA has approved several new drugs and new uses for older drugs in the past year that improve the chances of successfully treating breast cancer. Recent follow-up research shows that Herceptin also may modestly extend the lives of terminal breast cancer patients. Updated survival figures reported from a two-year study by one of the drug's key developers from the University of California at Los Angeles showed the risk of death to be 16 percent lower in those getting Herceptin. Selection of patients who are most likely to benefit from Herceptin is important because of the possible serious risks from the drug, including weakening of the heart muscle that can lead to congestive heart failure. FDA also approved in September a test called DAKO HercepTest to measure HER2 protein in tumors.
Doctors know that estrogen promotes the growth of breast cancer cells.
Tamoxifen interferes with the activity of estrogen by slowing or stopping the growth of cancer cells already present in the body. As adjuvant therapy, tamoxifen has been shown to help prevent the original breast cancer from returning, and also the development of new cancers in the other breast. An NCI study showed that the drug reduced the chance of getting breast cancer by 44 percent in women who were judged to be at increased risk for the disease. FDA emphasizes, however, that tamoxifen, manufactured by Zeneca Pharmaceutical Inc., Wilmington, Del., will not eliminate breast cancer risk completely, and should be used only following a medical evaluation of individual risk factors. Xeloda does not kill the cancer cells directly.