Weigh Hormones’ Risk, Experts Urge
The startling finding that a popular hormone therapy used to treat menopause and prevent osteoporosis may promote breast cancer left many women wondering this week whether they should reconsider taking so-called replacement hormones.
The finding, announced Tuesday in Sweden, emerged from a study of women over age 34 who took hormones for at least six years. While estrogen alone had a slight impact on their risk of breast cancer, estrogen and progestin together raised it fourfold.
That conclusion, contradicting findings of previous studies, has raised disturbing questions for the millions of women on hormone therapy: Should women on the combined therapy reconsider? How can they best weigh the risks and benefits?
Most experts in gynecology and cancer interviewed this week advised against any sweeping change in treatment. They said the finding is too preliminary, and the benefits of hormone therapy too great, to warrant immediate changes based on a single study.
But they said the Swedish research raises serious concerns about a long-suspected link between breast cancer and hormones. They said women must weigh carefully with their physician the risks and benefits of hormone therapy in their individual cases.
For example, a woman with a family history of breast cancer might opt against hormones. A woman predisposed to osteoporosis, or brittle bones, might take them. Women at risk of heart disease might take estrogen, since some researchers believe it cuts heart-disease risk.
Women also should consider whether they really need long-term therapy, or could get by taking hormones for a limited time, experts said. Studies suggest there may be no increased chance of breast cancer in women who take hormones for up to four or five years.
Trade-Offs Unavoidable
“You’ve got several different types of diseases to consider,” said Dr. I. Craig Henderson of the Dana Farber Cancer Institute in Boston. “Every time you make one change in the management and prevention of one problem, it affects others.
“That means you’ve got to make trade-offs,” he said. “The only person who can make those trade-offs is the woman. I don’t think any doctor or health agency can make a definite statement that (one particular therapy) is the way to go.”
The study, by U.S. and Swedish researchers, involved 23,244 Swedish women who received replacement estrogen. That therapy is used widely to treat symptoms of menopause, such as hot flashes, and to prevent the bone thinning that afflicts many older women.
Overall, the women who received estrogen were 10% more likely than others to develop breast cancer during the six-year study. The risk rose with the length of treatment: Those on estrogen for at least nine years were 70% more likely to develop cancer.
Differing Results
Much of the increased risk came from women on estradiol, a potent form of estrogen used widely in Europe but not often in the United States. Another form, called conjugated estrogens, used commonly here, was not associated with any increased chance of cancer.
The study’s most provocative finding was the fourfold rise in risk among the women who took both estrogen and progestin, a synthetic form of progesterone used increasingly since the early 1980s to counteract the tendency of estrogen to encourage uterine cancer.
“(That finding) suggests the progestin association increases the chance of breast cancer,” said Dr. Howard Judd, a professor of obstetrics and gynecology at UCLA School of Medicine. “Well, there are other data (from an earlier study) that suggest it does the opposite. There is no unanimity of opinion.”
Judd and others said the finding must be confirmed in further studies before current practice is changed. They noted that the numbers of women on combined therapy in the Swedish study were small, casting doubt on the statistical reliability of the finding.
Benefits Must Be Weighed
They also emphasized the proven benefits of estrogen therapy, which takes the place of natural estrogen produced by a woman’s ovaries until menopause. For some women, the risk of osteoporosis or heart disease is greater than the risk of breast cancer, physicians said.
But many healthy women have no natural tendency to bone-thinning or heart disease and might not want long-term hormone therapy, others said. They might take more natural--but less proven--preventive steps, such as increasing their dietary calcium and getting more exercise.
“We think that women should be screened more carefully” to determine whether they are truly at risk for conditions that long-term therapy prevents, said Cynthia Pearson, acting director of the National Women’s Health Network, a Washington, D.C.-based advocacy group.
Several experts said that women who have had a hysterectomy probably should not take combined estrogen and progestin; because they have no uterus, they do not need progestin’s protection against uterine cancer, and could be facing added breast cancer risk.
‘Not Innocuous’
“(This paper) certainly should alert patients, doctors and researchers that all the answers are not in,” said Dr. Elizabeth Barrett-Connor, chairwoman of community and family medicine at UC San Diego School of Medicine. “These decisions must be made with the understanding that this is potentially not a totally innocuous drug.”
“Some people think that if they take a pill, they are protected from all the ills of the world,” said Dr. S.B. Gusberg, a past president of the American Cancer Society, “because, like the old shamans in primitive societies, it has a magical quality.”
