Hormone-Blocking Drug May Aid in Preventing Heart Disease

A hormone-blocking drug widely used to prevent the recurrence of breast cancer may also help guard against heart disease, researchers reported Tuesday.

In a two-year study of 140 post-menopausal women who had undergone surgery for early breast cancer, researchers found that the drug tamoxifen not only reduced the chance that cancer would return, but also significantly lowered cholesterol levels. Many studies have shown high cholesterol levels to be a major risk factor for heart disease.

Since 1988, tamoxifen, which blocks the uptake by cells of the hormone estrogen, has been widely used as an after-surgery treatment for women stricken by estrogen-dependent breast cancers. About half of the 150,000 U.S. women diagnosed with breast cancer each year have tumors whose growth is spurred by estrogen.

Previous studies have shown that tamoxifen reduces the death rate by about 20% among breast cancer patients 50 or older. Tamoxifen is sold under the trade name Nolvadex by ICI Pharma of Wilmington, Del.

Now, reporting in the Journal of the National Cancer Institute, a University of Wisconsin-Madison team says its study found that tamoxifen lowered the women’s total blood cholesterol an average of 12% and the levels of low density lipoprotein, called LDL or “bad” cholesterol, about 20%.

“One would project that the lipid and lipoprotein changes observed . . . would confer a substantial reduction, perhaps in the vicinity of 40%, in the risk of coronary heart disease,” wrote Dr. Ross Prentice of the Fred Hutchinson Cancer Research Center in Seattle.