New drug cuts breast cancer risk in half
There's new hope for women at high risk of developing breast cancer, as a new study has found that a drug called Arimidex (anastrozole) significantly lowers the risk of postmenopausal women developing breast cancer by over 50 percent.
The results of the study will be published in the journal The Lancet. In the meantime, researchers are hopeful their findings will help prevent breast cancer in women who are at higher risk of getting the disease.
In a news release from the American Association for Cancer Research, lead study author Jack Cuzick said that Arimidex was more effective and had fewer side effects than two other existing breast cancer prevention drugs, tamoxifen and raloxifene.
Cuzic, who’s the head of the Cancer Research U.K. Centre for Cancer Prevention and director of the Wolfson Institute of Preventive Medicine at Queen Mary University of London, hopes the findings of the study will open the door to an alternate treatment for the prevention of breast cancer in postmenopausal women who are at high risk of developing the disease and are unable to tolerate the side effects of other anti-hormone breast cancer prevention medications.
In the United States alone, nearly 80 percent of women with breast cancer have large amounts of hormone receptors, with the hormone estrogen promoting the growth of cancerous tumors. However, Arimidex is an anti-hormone drug that shuts down the production of estrogen in the body; thus, it is used to treat postmenopausal women who have breast cancer with high levels of hormone receptors.
Over 3800 postmenopausal women participated in the study. Each participant had a higher risk for developing breast cancer due to having either: 1) two or more blood relatives with breast cancer; 2) a mother or sister diagnosed with breast cancer before age 50; or 3) a mother or sister with breast cancer in both breasts.
For the study, nearly 50 percent of the participants took the drug Arimidex for a period of five years. The remaining half of the women were given a placebo instead.
As a result, the research team found that the women who took Arimidex were had a 53 percent greater chance of not developing breast cancer, compared with the women who took a placebo.
Some of the women who took Arimidex reported experiencing side effects, such as hot flashes and minor aches and pains, but otherwise the drug was well-tolerated.
The low side effect profile of Arimidex is good news for women at high risk for getting breast cancer, especially those who cannot tolerate the side effects of tamoxifen or raloxifene, which include an increased risk of blood clots and uterine cancer.
However, with Arimidex having fewer side effects and being more effective in preventing breast cancer in high-risk women, chances are the drug will be more readily taken, and therefore help to reduce the number of women who develop the disease.
Meanwhile, study author Cuzick said that they plan to keep following the women who participated in the study for at least another 10 years in order to find out if the drug continues to help prevent breast cancer after women stop taking it. They also want to make sure there are no long-term adverse side effects.
SOURCE: American Association for Cancer Research, Antihormone Therapy Anastrozole May Provide New Option for Breast Cancer Prevention, December 12, 2013.