A second member of a new class of drugs has proved more effective than the gold standard, tamoxifen, at preventing breast cancer from recurring in women who received the medicine as initial therapy right after surgery. The drug, Femara, is expected to win Food and Drug Administration approval soon for women Femara and Arimidex, a similar drug already licensed for early breast cancer, are aromatase inhibitors, which block production of estrogen, a hormone that fuels the growth of most tumors that develop after menopause. Tamoxifen works differently, by blunting the ability of estrogen to enter cells. A study reported earlier this year in Europe and published in Thursday's New England Journal of Medicine estimated that 84 percent of women given Femara versus 81 percent of those on tamoxifen would be alive without any signs of cancer five years after starting treatment. The estimates were based on roughly two years of information on relapses among the 8,000 women in the study, done by researchers in the United States, Europe and Australia. Many of the researchers own stock in or are consultants for Novartis or companies with rival drugs. Several have shown Femara or Arimidex to be better either as initial treatment or after a couple years of tamoxifen."These trials, with close to 30,000 participants, consistently demonstrate that treatment with an aromatase inhibitor alone or after tamoxifen treatment is beneficial," Dr. Sandra Swain of the National Cancer Institute wrote in an editorial in the journal. In 2006, the large STAR clinical study concluded that raloxifene is equally effective in reducing the incidence of breast cancer, but after an average 4-year follow-up, although the difference was not statistically significant, there were 36% fewer uterine cancers and 29% fewer blood clots in women taking raloxifene than in women taking tamoxifen. Tamoxifen improves fertility in males with infertility by disinhibiting the hypothalamic–pituitary–gonadal axis (HPG axis) via ER antagonism and thereby increasing the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and increasing testicular testosterone production. It is taken as a preventative measure in small doses, or used at the onset of any symptoms such as nipple soreness or sensitivity. Other drugs are taken for similar purposes such as clomifene and the anti-aromatase drugs which are used in order to try to avoid the hormone-related adverse effects. Occasionally tamoxifen is used in treatment of the rare conditions of retroperitoneal fibrosis A report in September 2009 from Health and Human Services' Agency for Healthcare Research and Quality suggests that tamoxifen, raloxifene, and tibolone used to treat breast cancer significantly reduce invasive breast cancer in midlife and older women, but also increase the risk of adverse side effects. Some cases of lower-limb lymphedema have been associated with the use of tamoxifen, due to the blood clots and deep vein thrombosis (DVT) that can be caused by this medication. Resolution of the blood clots or DVT is needed before lymphedema treatment can be initiated.
Tamoxifen blocks the actions of estrogen and is used to treat and prevent some types of breast cancer. Learn about side effects, interactions and indications. Tamoxifen, sold under the brand name Nolvadex among others, is a medication that is used to prevent breast cancer in women and treat breast cancer in women and men.