Designer Estrogen Compares to Real Thing
March 21, 2001 (Orlando, Fla.) -- Evista may be the estrogen
substitute that has all the advantages of estrogen but none of the risks, says
Elizabeth Barrett-Connor, MD, who presented new data here Wednesday at a
meeting of the American College of Cardiologists.
In younger women, the female hormone estrogen protects against
bone loss, or osteoporosis. But giving estrogen replacement therapy after
menopause increases the risk for breast and ovarian cancer. That's where Evista
enters the picture. The drug belongs to a class of estrogen knock-off drugs
called selective estrogen receptor modulators, or SERMs. The drug is FDA
approved for treatment or prevention of osteoporosis.
In addition to its bone-protective effect, many heart experts
believed that estrogen protects the heart as well. The reasoning here was that
women don't usually have heart attacks until they are past menopause, when they
stop producing estrogen.
In recent years, however, two major medical studies have linked
estrogen to an increased risk for early heart attack, says Barrett-Connor, a
finding that left many heart experts worrying that Evista could be just as
But now, data collected from a large study of women who took
Evista to treat osteoporosis suggest that there may be some important -- and
comforting -- differences between Evista and estrogen.
"[T]here is no evidence of early harm [to the heart] with
raloxifene," says Barrett-Connor, a professor of medicine at the University
of California, San Diego. In fact, she says that Evista may lower cholesterol,
the same positive effect that is also seen with estrogen use. "It lowers
total cholesterol and LDL but does not appear to have an effect on HDL,"
she says. LDL is the so-called "bad" cholesterol that is linked to
heart disease, and HDL, or good cholesterol, protects the heart.
Although estrogen does appear to offer a long-term benefit in
protecting the heart from disease, Evista doesn't. She says, however, that the
new findings are not the final word on Evista. The data come from an
osteoporosis study, "not a heart study, and so the study wasn't really
designed to look for heart disease," she says. Also, most of the women
studied were actually pretty healthy: 7,000 women were enrolled in the study,
but only 202 had heart disease.
Sidney Smith, MD, chief science officer for the American Heart
Association, agrees. "I think we need a larger study that is designed to
look at these specific questions," he tells WebMD. "Nonetheless, these
results are certainly reassuring."
Barrett-Connor tells WebMD that a larger trial is already
looking at the potential heart benefits of Evista. But results from that study
"won't be available for several years," she says.
And she points out that the women in the osteoporosis study
were only followed for three years. "That may not be long enough to see a
long-term benefit," says Barrett-Connor.