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Is there a pill that prevents breast cancer?

In a large study that ended in 1998, the drug tamoxifen was shown to be effective in preventing breast cancer in women at increased risk of the disease. The breast cancer risk of the women who took tamoxifen was 49 percent lower than the risk of those who did not take the drug. As a result of this study, women at increased risk for breast cancer may consider taking tamoxifen to prevent the disease.

Tamoxifen has been used for more than 20 years to treat patients with advanced breast cancer. The drug works against the effects of the hormone estrogen, which promotes the growth of breast cancer cells.

However, there are risks associated with tamoxifen as well. Some are even life threatening. A women considering tamoxifen should carefully discuss the benefits and risks with her doctor.

In a current study, tamoxifen is being compared to raloxifene, a drug that is used to treat osteoporosis (weakening of the bones). Called STAR (Study of Tamoxifen and Raloxifene), this study will find out if raloxifene is more or less effective at preventing breast cancer than tamoxifen. Researchers also will compare the side effects of the two drugs.

STAR will involve about 22,000 postmenopausal women who are at least 35 years old and at increased risk of breast cancer. Women may enroll at various sites across the country. For more information about STAR, call the Cancer Information Service at 1-800-4-CANCER or go to and type STAR in the search box.


Source: "Ask the CIS" by the Cancer Information Service. "Ask the CIS" is distributed by the Cancer Information Service (CIS) of the Heartland, which serves Kansas, Nebraska, Missouri & Illinois. The CIS is a program of the National Cancer Institute. Call the CIS toll-free at 1-800-4-CANCER (1-800-422-6237) between 9 a.m. and 4:30 p.m. local time.

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Last update: Wednesday, November 26, 2008




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