Cure-all drug remains risky.

• Position: Breast Tumors - Brief Article

The drug tamoxifen citrate not only helps prevent recurrence of breast cancer, but can keep the deadly disease from appearing in the first place in some women. However, a University of North Carolina at Chapel Hill study indicates that it remains unlikely that tamoxifen ever will be given widely to women to prevent breast cancer, as the drug would avert only a maximum of six to eight percent of breast tumors in eligible females.

"Our calculations showed that tamoxifen's possibly harmful side effects, including blood clots and stroke, would rule out some 90% of women who might benefit from taking it each day," states Russell P. Harris, associate professor of medicine. Tamoxifen works in women by blocking what is known as the estrogen receptor that allows the hormone to work. Most breast cancer development is dependent on estrogen.

The study had women--ages 40 to 69--in 10 general internal medicine practices fill out questionnaires about their health and family histories of breast cancer. Then, using a proven formula for assessing breast cancer incidence and factoring in...