EVERY WOMAN'S DILEMMA

By J. MADELEINE NASH

To take estrogen or not to take estrogen? For millions of women approaching menopause, no other decision stirs up more anxiety or stimulates more debate. On the one hand, study after study has shown that replenishing lost stores of this potent hormone can ward off many of the ailments associated with aging--heart disease, osteoporosis, perhaps even Alzheimer's. On the other hand, many of these same studies also suggest that long-term use of estrogen increases the likelihood that a woman will develop breast cancer.

To untangle this knot of contradictory advice, women have desperately sought better information. And last week the New England Journal of Medicine provided the best they're likely to get for some time. In the largest study of its kind, a team of researchers led by Francine Grodstein of Boston's Brigham and Women's Hospital tracked the health histories of some 60,000 post-menopausal nurses over a period of 18 years. The results boil down the benefits and risks of estrogen to a fairly concise set of percentages.

On average, Grodstein and her colleagues report, women who took hormone supplements (mainly Premarin, a form of estrogen derived from mares' urine) for up to 10 years lowered their death rate from all causes an impressive 37%. Some women clearly benefited more than others, however. The mortality rate for women with one or more risk factors for heart disease, for example, dropped 49% compared with only 11% for women with no risk factors (that is, women who are nonsmokers, who are not overweight and who don't have high blood pressure, diabetes or a family history of heart disease).

Estrogen users with family histories of breast cancer, on the other hand, did better than many might have expected, scoring a 35% drop in overall mortality. There could be many reasons for this, says Grodstein. For one thing, heart attacks and strokes are more likely to be immediately lethal, so preventing them adds up to longer survival. For another, women on hormone therapy tend to be more closely monitored; their cancers are likely to be detected earlier.

Women who stayed on estrogen for more than 10 years, however, derived a more modest benefit. Reason? Their risk of dying from breast cancer shot up 43%, enough to offset the positive effects of estrogen, Grodstein says, but not enough to eliminate them entirely. Despite the rise in breast-cancer deaths, the researchers found that long-term estrogen users still had a 20% lower death rate. Over the coming years, Grodstein and her colleagues hope to find out what happens when women use estrogen for even longer periods. Does their breast-cancer risk continue to rise, or does it level off? What happens to their risk of heart disease? "We don't know anything about the risks and benefits of keeping women on hormones for 20 and 30 years," says Grodstein.

In the absence of these data, what should women do? One option gaining currency is to postpone long-term estrogen therapy until they are older. Women typically enter menopause between the ages of 45 and 55, but their risk of heart disease and osteoporosis doesn't really soar until they reach their 60s and 70s. By starting estrogen therapy later in life, it may be possible for women to capitalize on its benefits while curtailing its power to harm.

--By J. Madeleine Nash