Osteoporosis Drug a Better HRT?

Evista Offers Promise of Disease Prevention for Older Women

From the WebMD Archives

June 5, 2003 -- New research is under way to determine if the broken promise of hormone replacement therapy with estrogen and progestins can be fulfilled after all.

The hope is that the osteoporosis drug Evista can lower the risk of breast cancer, heart disease, and osteoporosis in elderly women without increasing their risk for other diseases. Evista is in a class of drugs known as selective estrogen receptor modulators (SERMs).

A study to be published in the July 1 issue of the journal Cancersuggests the Evista investigation may be on the right track: Researchers believe SERM treatment in breast cancer patients may protect them against heart attack.

Lower Heart-Attack Risk

They found that survivors of early breast cancer had a one-third lower risk of heart attack than women without breast cancer. The relationship between lower heart-attack risk in breast cancer survivors was even more significant in women with documented risk factors for heart disease.

The preliminary findings must be confirmed in clinical trials. But lead researcher Elizabeth Lamont, MD, speculates it is not the breast cancer itself, but the treatment for the disease protects against heart disease. The estrogen-modulating drug tamoxifen is the most widely used drug therapy for early-stage breast cancer, and it has also been shown to lower cholesterol levels and protect against osteoporosis.

Tamoxifen and Evista (raloxifene) are both SERMs, meaning they act on some parts of the body that are responsive to the hormone estrogen -- but not all. Evista is considered a more promising drug for prevention of diseases other than breast cancer because it is safer than tamoxifen. Tamoxifen has some estrogen-like effects especially within the uterus and can increase the risk of endometrial cancer.

"Evista lowers LDL cholesterol and does many of the good things tamoxifen does, but it doesn't seem to have the estrogenic tickle that is associated with an increased risk for endometrial cancer," says cancer researcher Craig Jordan, PhD, who developed tamoxifen three decades ago.

"It may be that Evista will protect against all of these diseases of aging, but we have to wait for the clinical evidence." Jordan is director of the Lynn Sage Breast Cancer Research Program at Northwestern University.


Could Provide 'Widespread' Protection

The Raloxifene Use for the Heart (RUTH) trial, which includes just over 10,000 women in 26 countries who are at risk for heart disease, is designed to determine whether the SERM lowers the risk of coronary events and reduces the risk of breast cancer.

Principal investigator Lori Mosca, MD, PhD, tells WebMD that definitive findings should be published within five years. Mosca is a spokeswoman for the American Heart Association and director of preventive cardiology at New York Presbyterian Hospital.

"This drug has the potential for very widespread utilization in postmenopausal women, because the conditions that it would impact -- heart disease, breast cancer, and osteoporosis -- are major health concerns," she says.

So is Evista the disease-prevention panacea for older women that the hormone replacement therapy Prempro was once thought to be? All agree that it is way too early to say. While Evista does not appear to promote endometrial cancer like tamoxifen does, its use is associated with a small risk in blood clots in the leg. And it can actually worsen hot flashes in menopausal women, especially in those closest to the onset on menopause.

"We thought we had a good preventive drug with hormone replacement therapy, but we now know that this is not true," Jordan tells WebMD. "Tamoxifen is good for the treatment of breast cancer, but it doesn't have the right safety profile to give to everyone. The hope is that Evista has a better safety profile and protects against heart attack, bone loss, and breast cancer."

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SOURCES: Cancer, July 1, 2003. Elizabeth B. Lamont, MD, medical oncologist; assistant professor of medicine, University of Chicago Medical Center. Craig Jordan, PhD, director of the Lynn Sage Breast Cancer Research Program at the Robert H. Lurie Comprehensive Cancer Center, Northwestern University. Lori Mosca, spokeswoman, American Heart Association, director of preventive cardiology, New York Presbyterian Hospital.
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