Another study presented at the San Antonio Breast Cancer Symposium also found Faslodex to be equal to Arimidex in helping to slow cancer growth and shrink tumor size. Both drugs were generally well-tolerated and side effects were similar. The most common side effects of Faslodex and Arimidex were hot flashes and stomach upset. Both studies show that Faslodex appears to be effective for women who have become resistant to tamoxifen, said Dr. Osborne. Further research will help determine the proper order in which these drugs would be most effective for women with advanced breast cancer.
Many breast cancers contain estrogen receptors within their cells.
To survive and reproduce, these cancers depend on the hormone estrogen. Researchers have found that using hormonal agents that prevent estrogen from binding to these receptors in cancer cells helps slow the growth of cancer. How the Drugs Treat Breast Cancer Tamoxifen Blocks estrogen from estrogen receptors in breast cancer cells. Arimidex Prevents production of estrogen in adrenal glands. Faslodex Destroys estrogen receptors in breast cancer cells.