The National Institutes of Health has tried to address questions about tamoxifen by issuing the following answers to common concerns and the clinical trial involving the drug.
Tamoxifen is a laboratory-made drug, taken in pill form.
It has been used for 25 years to treat patients with advanced breast cancer. Tamoxifen works against breast cancer, in part, by interfering with the activity of estrogen, a female hormone that promotes the growth of breast cancer cells. In treatment, the drug slows or stops the growth of these cancer cells. Research has shown that taking tamoxifen for breast cancer not only helps prevent the original breast cancer from returning but also helps to prevent the development of new cancers in the other breast. Researchers believed that tamoxifen might have a similar beneficial effect for women at increased risk of breast cancer.