By 2002, one-third of American women over 50 were being prescribed combination progestin-estrogen hormone therapy. By 2002, one-third of American women over 50 were being prescribed combination progestin-estrogen hormone therapy. (iStock)

Once marketed as a fountain of youth, hormone replacement therapy is now believed to be just the opposite. Even the term hormone replacement therapy (H.R.T.) has come under fire.

"The concept of replacement suggests women need this," says Dr. Marcia Stefanick, a professor of medicine at Stanford University. "Until you can prove menopausal hormones help women, 'replacement' is not an appropriate term for something that does more harm than good."

Menopausal hormones were once touted as science's answer to aging. Hormones offered women relief from hot flashes and headaches. Doctors prescribed them to women to prevent osteoporosis and heart disease. Modern-day alchemists claimed they kept skin young, memory sharp and 50-somethings feeling better than ever. By 2002, one-third of American women over 50 were being prescribed combination progestin-estrogen hormone therapy.

That same year, a landmark study by the Women's Health Initiative was halted when women taking combination therapy showed higher incidences of breast cancer, heart attacks, strokes and blood clots than women on placebo. The same women did show slightly decreased risks of hip fractures and colon cancer, but those benefits were not enough to outweigh the risks.

Those results were enough to keep doctors from prescribing menopausal hormones and scare millions of women into foregoing them. A year after the study was stopped, the number of women prescribed combination hormone therapy dropped by two-thirds from 60 million to 20 million. For that same year, the National Cancer Institute reported a huge decline in breast cancer cases — the largest such decline for a single cancer in a single year.

The findings pointed to an undeniable link between menopausal hormones and breast cancer. But that conclusion was not without controversy. Many doctors warned that the study's older age group and increased mammogram use had muddied the waters. The controversy became the scourge of post-menopausal women everywhere looking for some relief from their misery.

Last February brought more bad news. A follow-up study published in the New England Journal of Medicine concluded that menopausal hormones are indeed the culprit. The study found that women taking combination progestin and estrogen therapy for more than five years doubled their risk of breast cancer — far greater correlation than the 27 per cent increase cited in the 2002 study.

A 'nuanced approach' to menopause

For the more than 2 million baby-boomer women now approaching menopause with a lack of alternatives to hormones, those findings are devastating. But a closer look at the facts reveals a more nuanced approach to dealing with menopause.

'The older you are, the higher the risk. That's why it's not OK for a 60-year-old woman to be taking hormones.'—Dr. Marcia Stefanick

For one, the typical 50 year old has less than a one per cent chance of developing breast cancer. So even a doubling of that risk leaves women with relatively good odds. Second, the latest study found that if women stop taking hormones before year four, their risk of developing breast cancer essentially drops back down to normal. Finally, recommended doses have now dropped by nearly half, from .625 milligrams per day of estrogen to a .325-mg dose and from 2.5-mg dose of progestin to a 1.5-mg dose.

That leaves women with a relative margin within which to take low-dose hormones with limited risk. Says Stefanick, who served as chairwoman of the steering committee for the Woman's Health Initiative, "The message is now: There is a time and place for hormones. Take as low a dose as you need, for the shortest duration necessary. But two to three years is the longest period women should be on hormones. After that, their risk has already doubled."

Before women take menopausal hormones, they need to assess whether they are at high-risk for breast cancer. "That's the $50 million question," says Stefanick. "There are a lot of women with breast cancer that sure wish they hadn't gone on hormones."

High-risk women include those with a family history of breast cancer; women who had children after the age of 30 or never had children at all; women who started menstruating before age 11; and much depends on age. "The older you are, the higher the risk. That's why it's not OK for a 60-year-old woman to be taking hormones," says Stefanick.

One risk factor that requires a further look is the amount of time women have spent taking oral contraceptives. Eighty percent of women in the United States have taken oral contraceptives at some point in their lifetime. But to date, no study has examined whether women taking menopausal hormones after taking oral contraceptives for a prolonged period of time put themselves at an even greater risk for breast cancer.

Another looming question: What risk does estrogen-only therapy pose for women? Estrogen-only treatment has been linked to cancer of the uterus. Progestin counteracts estrogen's effect in the uterus, which is why the two are prescribed in tandem.

Stefanick and her colleagues are still examining results of a second follow-up study analyzing the correlation between estrogen-only treatment and breast cancer. To date, results suggest that estrogen poses no increased risk of breast cancer. If those results are conclusive, that could be good news for women who have undergone hysterectomies. They could still benefit from estrogen-only treatment, without the risk.