Information that can help women compare the risks and benefits of taking the drug tamoxifen to prevent breast cancer is presented in the November 3 issue of the Journal of the National Cancer Institute.
The information comes from a study by Mitchell Gail, M.D., Ph.D., of the National Cancer Institute, and colleagues. Their work was prompted by findings that, in certain circumstances, women at high risk for developing breast cancer can lower that risk substantially by taking tamoxifen as a preventative measure. Data used by Gail et al. came from the Breast Cancer Prevention Trial (BCPT) and other studies.
The BCPT involved women aged 60 and older or those aged 35-59 who had at least the same risk of breast cancer as the average 60-year-old white woman in the United States. The BCPT showed that tamoxifen (20 milligrams daily for up to 5 years) cut the risk of invasive breast cancer by 49% and the risk of noninvasive breast cancer by 50%, compared with placebo. Tamoxifen also reduced the incidence of hip fractures. However, some women in the trial developed adverse effects from tamoxifen, including increased risk of endometrial cancer, pulmonary embolism, stroke, deep vein thrombosis, and cataracts. Thus, determining whether to take tamoxifen requires weighing the various risks and benefits.
The risks and benefits depend on age and race and on a woman's specific risk factors for breast cancer. Current age, number of first-degree relatives with breast cancer, and several other factors are used to predict breast cancer risk. The risks for stroke, pulmonary embolism, and deep vein thrombosis increase with age and are two to three times higher in black women than in white women, whereas the risk of hip fractures and endometrial cancer are lower in black women.
The paper describes the risks and benefits of tamoxifen for a woman with particular risk factors so that the woman can examine each of the outcomes separately and can also use summary indices that weigh the various outcomes. Tamoxifen is especially beneficial for younger women with a substantially elevated risk of breast cancer.
Because a woman's preferences and risk factors can change over time, the authors note that decisions about tamoxifen are not irreversible, and development of new cancer preventing agents may lead to further options.
In an editorial, Anne Taylor, M.D., Lucille Adams-Campbell, Ph.D., and Jackson Wright, Jr., M.D., Ph.D., note that the BCPT trials of over 13,000 participants included only 220 African American women and 249 women of other ethnic backgrounds. As a result, the authors say, it is not possible to estimate with any confidence either the positive or negative effects tamoxifen in minority women, and the guidelines proposed by Gail et al. can be more easily applied to white women than to other ethnic groups. This situation reaffirms the need to aggressively recruit minority populations in NCI-sponsored trials in proportion to the disease load in the population, they conclude.
Contact: NCI Press Office, (301) 496-6641. (Note: The media contact for this paper is the NCI Press Office because the author is on the NCI staff.) Editorial: Dr. Anne Taylor, (216) 844- 5365; fax (216) 844-3145.
Note: This memo to reporters is from the Journal staff and is not an official release of the National Cancer Institute (NCI) or Oxford University Press (OUP) nor does it reflect NCI or OUP policy. In addition, unless otherwise stated, all articles and items published in the Journal reflect the individual views of the authors and not necessarily the official points of view held by NCI, any other component of the U.S. government, OUP, or the organizations with which the authors are affiliated. Neither NCI nor any other component of the U.S. government nor OUP assumes any responsibility for the completeness of the articles or other items or the accuracy of the conclusions reached therein.
![]() |
||||
|
Oxford University Press Privacy Policy and Legal Statement |