Recent Developments in Drug Treatment of Advanced Breast Cancer (dateline December 18, 2000)
|Nearly 183,000 new cases of breast
cancer will be diagnosed by the end of 2000 and many of those cancers will have already
progressed to advanced stages before they are detected. The
approach to treating advanced (metastatic) breast cancer focuses largely on relieving
cancer symptoms and extending survival time. Recently, researchers have been investigating
several drugs (or new combinations of drugs) that may give women with advanced breast cancer more treatment options.
Arimidex. Two recent studies published in the Journal of Clinical Oncology find that the drug Arimidex (generic name, anastrozole) may be as effective as tamoxifen (brand name, Nolvadex) in treating women with advanced breast cancer.(1,2) After treating over 1,000 advanced breast cancer patients with either tamoxifen or Arimidex and following them for 18 to 19 months, researchers found similar results in terms of tumor shrinkage regardless of whether the women took tamoxifen or Arimidex. While both drugs were well tolerated by the women in the studies, one study found that women who took Arimidex tended to experience less vaginal bleeding or blood clotting than the women who took tamoxifen.
While further research is needed before researchers can determine whether Arimidex is a better treatment than tamoxifen for women with advanced breast cancer, this recent data is promising. Arimidex is currently approved by the U.S. Food and Drug Administration (FDA) to treat advanced breast cancer patients who have not responded well to treatment with tamoxifen. Arimidex is an aromatase inhibitor and works by preventing the production of estrogen in the adrenal glands. Click here to learn more about Arimidex.
Femara. An FDA advisory panel has unanimously recommended that the FDA approve the drug Femara (generic name, letrozole) as an initial treatment for women with advanced breast cancer. In November 2000, two studies on Femara were presented at the Chemotherapy Foundation Symposium XVIII in New York.(3) The first study of 900 advanced breast cancer patients found that the number of women whose cancer had not progressed was nearly 50% greater among those who took Femara, compared with the women who took tamoxifen. In the second study, Femara was shown to be more effective at shrinking the size of breast cancer tumors than tamoxifen.
Femara is currently FDA approved to treat advanced breast cancer patients who do not respond well to tamoxifen. Femara works by reducing the total amount of estrogen in the body (circulating estrogen levels), thereby limiting the amount of estrogen that can affect breast cancer cells. Click here to learn more about Femara.
Xeloda and Taxotere. While the drugs Xeloda (generic name, capecitabine) and Taxotere (generic name, docetaxel) have both been shown to be effective on their own, researchers have found that combining the two drugs helps women with advanced breast cancer live longer.(4) In a 16-nation clinical study presented at the San Antonio Breast Cancer Symposium in December 2000, researchers found that combining Xeloda and Taxotere may help improve the time in which a tumor responds to therapy, slow tumor progression, and extend survival time for women with advanced breast cancer.
Herceptin, Taxol, and Paraplatin. Research continues to show that the drug Herceptin (generic name, trastuzumab) can be effective in treating women with advanced breast cancer whose tumors contain extra copies of the HER2 (also written HER-2/neu) gene. At the San Antonio Breast Cancer Symposium in December 2000, researchers from the Sarah Cannon Cancer Center in Nashville, Tennessee found that among 46 patients who over-expressed the HER2 gene, 25% of the tumors responded to Herceptin.(5) Among those patients who added a weekly regimen of the drug Taxol (generic name, paclitaxel) and Paraplatin (generic name, carboplatin) to Herceptin, 56% showed some response. Weekly Taxol and Paraplatin without Herceptin was also effective in some advanced breast cancer patients who did not respond well to Herceptin.
Herceptin is FDA approved to treat advanced (metastatic) breast cancer in women who over-express the HER2 gene. Herceptin seeks out HER2 and attaches itself to the protein receptor on the surface of cells. By binding to the cells, Herceptin has been shown to slow the growth and spread of tumors that have an overabundance of HER2 protein receptors. Taxol and Paraplatin are both chemotherapy drugs. Taxol works by disrupting cell division. Paraplatin also works by disrupts the growth of cancer cells, which are then destroyed.