Women have been scared during the last several weeks with new studies about alleged health risks from hormone replacement therapy (HRT). This scare contrasts starkly with the preceding decades of HRT being touted as the fountain of youth.

What should women and their physicians believe? Past hype? Recent hysteria?

Neither.

HRT, originally estrogen alone and later estrogen in combination with progestin, was approved in 1942 by the Food and Drug Administration to relieve the short-term symptoms of menopause such as night sweats and hot flashes.

Two decades later, though, HRT began being touted as a wonder drug for many long-term health concerns of women, not just menopausal symptoms. HRT mania was kicked off by Dr. Robert Wilson's 1966 book Feminine Forever. Unknown at the time, the book was financed by Wyeth-Ayerst, the leading manufacturer of HRT.

Studies appeared in the scientific literature touting HRT as reducing bone loss, the risk of heart disease and the risk of some cancers.

But anyone who paid attention to the data rather than the hype would have known that these studies didn’t at all demonstrate HRT to be a panacea.

The studies invariably reported weak statistical correlations between HRT use and long-term health benefits -- and that's with the study populations biased in favor of the reported results.

The study populations taking HRT tended to be comprised of thinner, wealthier and better-educated women under physician care. It is not surprising that these women were healthier than the women in the "control" groups.

Myths about the long-term benefits of HRT nevertheless took hold. Premarin, the most popular HRT made by Wyeth-Ayerst, was recently used by about 12 million women in the U.S. at a cost of about $180 per year.

Or it used to be so widely used.

Early July saw a rash of epidemiologic (human population) studies allegedly linking HRT with a variety of health risks. "NIH says type of hormone therapy hurts instead of helping women's hearts and causes breast cancer," headlined The Associated Press.

The New York Times quoted a female physician stating, "I may have taken my last pill this morning."

But the most notable of the recent studies reported that, among 8,506 estrogen-plus-progestin HRT users, there was only a 29 percent increase in heart disease occurrence. The result was barely statistically significant, meaning there’s a worrisome possibility it was a fluke.

The study reported only a 26 percent increase in breast cancer occurrence. That result wasn't statistically significant.

The study's reported results for other health concerns were of similar magnitude and statistical significance -- that is to say, weak.

But you don't have to accept my characterization of such results.

As the National Cancer Institute points out: "In epidemiologic research, [risks of less than 100 percent] are considered small and usually difficult to interpret. Such increases may be due to chance, statistical bias or effects of confounding factors that are sometimes not evident."

In other words, these results should be treated as preliminary -- particularly until they are replicated many times by independent researchers. That's just Scientific Method 101.

Moreover, these women were only studied for five years and previous studies report contradictory results. It seems the panic is premature.

David Sturdee, former chairman of the British Menopause Society, once said: "A lot of nonsense is talked by those who say HRT is the best thing since sliced bread. Equally, I am incensed by the idea that all HRT is unsafe. Some women feel undue pressure either to take HRT or not to."

What kind of pressure? Wyeth-Ayerst pressed women to take HRT. Now others are trying to scare women about HRT.

Pharmaceutical manufacturer Eli Lilly promoted HRT fears in the fall of 1997 as it awaited approval of it rival drug, raloxifene (Evista).

Lilly placed full-page advertisements in women's magazines that ominously read, "Many women have serious worries about a possible link between estrogen replacements and cancer." The implication was that Evista didn't increase cancer risk.

Lilly even touted preliminary studies reporting a slight decrease in cancer risk among Evista users.

This marketing-by-scaremongering was eventually brought to a halt by a federal judge who issued an injunction against Lilly touting research that did not prove Evista prevented breast cancer.

No one disputes the short-term benefits of HRT for menopausal symptoms. Moreover, there is no substitute for it. But HRT's supposed long-term benefits and risks so far seem to have more to do with unscrupulous marketing than science.