Women's Health

Few Women Want Drug to Prevent Breast Cancer

April 11, 2005 -- In a new study of women at higher risk of breast cancer, few said they were willing to take the drug tamoxifen to prevent the disease.

Only about 18% of the 255 women surveyed said they were inclined to take tamoxifen, says the study in Cancer's May 15 edition.

The women expressed their opinions after being informed about tamoxifen's risks and benefits. Possible side effects were the most commonly cited concern. The results weren't affected by the women's perceptions about their breast cancer risk.

"The current results indicate that many high-risk women are unwilling to consider tamoxifen even with extensive education about its potential benefits and harms," write the researchers, who included Joy Melnikow, MD, MPH, of the University of California-Davis.

About Tamoxifen

Tamoxifen is a commonly prescribed medication for treating breast cancer. It's also used to help prevent breast cancer in women at high risk for the disease.

Tamoxifen blocks estrogen, a hormone that causes many breast cancers to grow.

Side effects include an increased risk of uterine cancer and blood clots, a small increase in the risk of stroke, and hot flashes.

On the other hand, tamoxifen helps prevent osteoporosis in women who've gone through menopause.

The FDA approved tamoxifen to reduce the risk of breast cancer in 1998, but the drug's use for that reason has been "controversial," write Melnikow and colleagues.

About 2 million U.S. women would experience a net benefit from taking tamoxifen, they say. But only an estimated 5% of tamoxifen sales by AstraZeneca -- the drug's maker -- are for the reduction of breast cancer risk, Melnikow notes.

Breast Cancer Treatment: Assess Your Options

Participants were 255 women at higher risk for breast cancer. None had developed breast cancer before.

Most of the women's breast cancer risk factors included being at least 50 years old. However, some women younger than this were included in the study. Other risk factors evaluated were race, age at first period, age at first live birth, family history, and history of previous breast biopsies.

First, the women got a 15-minute presentation on tamoxifen's pros and cons. Next, they answered questions about their views on tamoxifen.

After the presentation, 18% of the women said they were inclined to take tamoxifen to lower their breast cancer risk. Participants with the highest breast cancer risk were no more likely to opt for tamoxifen than others.