Osteoporosis Drug a Better HRT?
Evista Offers Promise of Disease Prevention for Older Women
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 Cancer suggests 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.