Weighing the Pros and Cons of Hormone Therapy

Making an informed decision about whether to take replacement hormones during and after menopause is hard enough for women with no prior health problems. It is far more difficult for a woman who has had breast cancer or who has a strong family history of this most common cancer in women. Because estrogen can stimulate the growth of a breast cancer, women and their doctors are understandably reluctant to consider hormone replacement for someone at high risk of developing a new or recurrent cancer.

But this means that such women may miss important health benefits of estrogen after menopause, among them a reduced risk of heart disease, osteoporosis and Alzheimer's disease as well as diminished menopausal symptoms like hot flashes, night sweats and vaginal dryness.

Last week's announcement that an advisory committee to the Food and Drug Administration is recommending approval of the drug tamoxifen to reduce the risk of developing breast cancer provides another, though imperfect, hormone replacement option for high-risk women. Though it has drawbacks, this so-called "designer estrogen" also offers women who take it an opportunity to glean some of the benefits of estrogen replacement, such as reduced risk of cardiovascular disease.

But these questions remain: Can some former breast cancer patients safely take hormone replacements, and if so, which ones? Are there reasonable alternatives that will grant women at least some benefits of estrogen without adding to their concerns about developing a new or recurrent cancer?

The answers concern 2.4 million American women, and millions more worldwide, who have survived breast cancer, as well as those at high risk of the disease. At a consensus conference last fall sponsored by The Hormone Foundation, the Susan G. Komen Breast Cancer Foundation and others, experts and patient advocates concluded that treating menopausal symptoms and long-term health risks in breast cancer patients should be "tailored to individual patients' needs" and employ strategies that "would avoid the use of estrogen while providing its benefits."

Why Worry About Estrogen?

Estrogen plays a critical role in the initiation and promotion of breast cancer. Many studies have shown that the longer a woman's breast is exposed to high levels of estrogen, the greater the chances of eventually getting breast cancer. The cells of most breast cancers have receptors for estrogen and respond to the hormone's growth-stimulating effects. Patients with these cancers are typically given treatments to block the effects of their own estrogens.

Recent findings strongly suggest that this increased risk extends to postmenopausal women who take replacement hormones, either estrogen alone or estrogen with progestin (the latter is added to protect the uterine lining from estrogen's growth-stimulating effect). For each year that women take these hormones, the risk of developing breast cancer rises slightly, by roughly equal to the increase associated with a one-year delay in the onset of menopause. After 10 years on hormone replacement, according to the experience of 80,000 nurses, the increase in risk is about 30 percent.

Further evidence of estrogen's influence on breast tissue comes from the effects of designer estrogens like tamoxifen. These substances act as weak estrogens and block the action of natural estrogen in some tissues. Tamoxifen has been shown to help prevent a new or recurrent breast cancer apparently by blocking the stimulating effects of natural estrogen on breast tissue. Early evidence presented recently shows a similar effect by a second designer estrogen, the bone-building drug raloxifene.

The Choices

Though not ideal substitutes for the real thing, designer estrogens offer high-risk women some estrogen benefits. Tamoxifen, for example, does reduce cardiac risk, but not to the extent that estrogen does. But tamoxifen, like estrogen, also stimulates cell growth in the uterus and increases the risk of uterine cancer. Raloxifene, marketed as Evista to help prevent osteoporosis, also has some of estrogen's cardiovascular benefits and, unlike tamoxifen, it does not stimulate uterine cell growth.

Ongoing research should lead to the development of better designer estrogens, perhaps one that protects the heart, bones and brain as well as the breast and uterus and diminishes menopausal symptoms. Meanwhile, what are the options for a menopausal woman who has had breast cancer or is at high risk of getting it?

First and foremost, she needs to adopt the healthy habits known to or strongly suspected of reducing the risk of heart disease, osteoporosis and Alzheimer's disease. This familiar list includes quitting smoking; achieving and maintaining a normal body weight; doing regular weight-bearing exercise like brisk walking or strength training; reducing consumption of meat and dairy fat, sugars and refined starches; and eating more vegetables, whole grains, beans and fish.

Also, a postmenopausal woman, even if she takes hormones, should consume at least 1,500 milligrams of calcium a day (from nonfat dairy products like yogurt and skim milk, calcium-rich vegetables and calcium-enriched orange juice supplemented, if needed, by calcium tablets). She might also take a daily supplement of vitamin E (200 to 800 international units, to protect against heart disease and Alzheimer's disease) and vitamin D (to bring her daily total to 800 international units, for proper absorption and use of calcium).

The Soy Story

Many menopausal women have recently turned to the lowly soybean as a substitute for replacement hormones, but the jury is still out on how effective it is. Soy contains weak estrogens called isoflavones, which may mimic some of the effects of natural estrogen. Despite glowing testimonials for soy foods like tofu, tempeh, soy milk and soy-based candy bars, properly designed studies have found that soy is only slightly more effective than a look-alike placebo in controlling hot flashes, a common and easily assessed symptom of menopause. Researchers suspect that soy may help some women substantially, others slightly and still others not at all. Still, experts say soy is worth a try for women with bothersome symptoms.

But, when it comes to the long-term benefits provided by natural estrogen, the data on soy are preliminary, the findings of studies are inconsistent and the amount of soy needed to gain significant benefit is far more than American women are likely to consume. Dr. Mark Messina of Loma Linda University in Loma Linda, Calif., who consults for the soy industry, said the ability of soy to protect against breast cancer, osteoporosis and heart disease is at best speculative.