Evista and Fareston

Evista (chemical name: raloxifene)

Evista is an anti-estrogen SERM medication that is also used to strengthen bones in women with osteoporosis. In September 2007, the U.S. Food and Drug Administration (FDA) approved using Evista to reduce the risk of breast cancer in post-menopausal women who are at high risk. The FDA also approved using Evista to reduce the risk of breast cancer in post-menopausal women with osteoporosis.

The approval of Evista as a risk reduction medicine was based on research results from the STAR Trial (Study of Tamoxifen And Raloxifene) released in July 2006. In that study, researchers found that Evista was as effective as tamoxifen in reducing the risk of breast cancer in post-menopausal women at increased risk, but with no personal history of the disease.

Another study, called the RUTH trial (Raloxifene Used for The Heart) studied Evista in women with a history of heart disease or who have high risk for heart disease to see if it can reduce heart problems. This is a completely different population than the women in the STAR Trial. Evista, like tamoxifen, has the ability to improve blood cholesterol levels by lowering low-density lipoprotein (LDL) cholesterol ("bad" cholesterol) and increasing high-density lipoprotein (HDL) cholesterol ("good" cholesterol). For this reason, researchers wanted to test whether it could reduce women's heart problems. The results of the RUTH Trial were released in July 2006, and showed that after more than 5 years of follow-up, no real improvement in heart problems was noted. This result isn't surprising, because similar results were obtained in studies of tamoxifen. The RUTH trial also found that taking Evista put some women at greater risk for dangerous blood clots. The risk of stroke was found to be the same in women taking Evista as those taking the placebo. However, among women who did have strokes during the time of the study, there were more women in the Evista group that had fatal strokes than in the placebo group.

After the FDA approved Evista to reduce the risk of breast cancer in post-menopausal women at high risk, Evista's packaging began carrying a warning that Evista increases the risk of both deep vein thrombosis (blood clots) and fatal strokes.

For a post-menopausal woman who is obese, smokes, and has a high risk of breast cancer, the risk-reducing benefits of Evista might be outweighed by a higher than average risk of blood clots and stroke. But if a woman has a strong family history of breast cancer AND a prior breast biopsy showing atypical ductal hyperplasia, the more than 80% reduction in breast cancer risk is probably worth the increased risk of blood clots. Taking medication also is a reasonable alternative to the aggressive risk reduction obtained through preventive surgery and all its associated risks and benefits.

Evista's safety and effectiveness in pre-menopausal women has not been studied and is unknown. For pre-menopausal women, tamoxifen is the medication of choice to help lower the risk of breast cancer.

Fareston (chemical name: toremifene)

Fareston is a relatively new anti-estrogen SERM with properties and side effects similar to tamoxifen's. Unlike tamoxifen, Fareston does not seem to increase the risk of endometrial cancer. Based on research that has been done so far, the U.S. Food and Drug Administration has approved Fareston only for post-menopausal women with advanced (metastatic) breast cancer. Fareston is not used often in the United States, because it has not been studied as much as tamoxifen and has only been tested in women with advanced disease.