As with almost any drug, tamoxifen has both benefits and potential harmful side effects. Understanding the balance between these benefits and risks is key to deciding whether tamoxifen is appropriate for an individual woman at higher risk who wants to lower her chances of developing breast cancer. (For information on tamoxifen for the treatment of breast cancer, click here).
Among women at increased risk of breast cancer, the benefits of tamoxifen largely outweigh the risks in :
- Women in their 40’s who aren’t likely to have blood clots
- Women in their 50’s who aren’t likely to have blood clots and who do not have a uterus (have had a hysterectomy)
Other women, though, may also benefit from tamoxifen. Talking with your health care provider can help clarify the specific issues you need to take into account when deciding whether or not to take tamoxifen.
To help in this decision making, the National Cancer Institute convened a workshop in 1998 to develop guidelines for the use of tamoxifen to reduce the risk of breast cancer . Figure 2.3 outlines these guidelines, which provide an estimate of the benefits/harms certain groups of women may have from tamoxifen. These are guidelines, however, and scientists cannot predict the benefit or harm to any one person. The report also stresses that health care providers need to take into account a woman’s individual characteristics when counseling her about tamoxifen use. This includes her baseline risk of stroke and uterine cancer as well as her tolerance of tamoxifen’s side effects.
Unfortunately, there are very few data detailing how the potential benefits and harms of tamoxifen apply to African American women and women of other ethnicities. It’s likely, however, that African American women get less benefit and greater harm from tamoxifen than white women. This is because African Americans have a lower rate of breast cancer than whites and are also more likely to have some of the harmful side effects of tamoxifen.