THE ESTROGEN DILEMMA

On Feb. 13, 1963, a new patient strode into the office of New York City gynecologist Robert A. Wilson. To Wilson, she was nothing less than a revelation or, to be more precise, a walking, talking confirmation of his most deeply held medical convictions. Wilson was a leading proponent of treating menopausal women with the female hormone estrogen. He was convinced that, given early enough and continued throughout life, hormone treatment could actually prevent what he called the "staggering catastrophe" of menopause and the "fast and painful aging process" that attended it.

Wilson's new patient, "Mrs. P.G.," as he later called her, said she was 52 years old, but her body told another story. "Her breasts were supple and firm, her carriage erect; she had good general muscle tone, no dryness of the mucous membranes and no visible genital atrophy. Above all," Wilson noted, "her skin was smooth and pliant as a girl's." When asked about menopause, she laughed and replied, "I assure you, Dr. Wilson, I have never yet missed a period. I'm so regular, astronomers could use me for timing the moon."

Pressed for her secret, the youthful matron eventually revealed she had been taking birth-control pills, containing estrogen and a second female hormone, progesterone. That was the very formula Wilson had developed as a means not only to treat menopausal complaints but also to forestall the aging process. Mrs. P.G. was a lush exemplar of his notion that "menopause is unnecessary. It can be prevented entirely."

Three years later, in a hugely successful book, Feminine Forever, Wilson announced the good news to all womankind. "For the first time in history," he wrote, "women may share the promise of tomorrow as biological equals of men ... Thanks to hormone therapy, they may look forward to prolonged well-being and extended youth."

Estrogen is indeed the closest thing in modern medicine to an elixir of youth -- a drug that slows the ravages of time for women. It is already the No. 1 prescription drug in America, and it is about to hit its demographic sweet spot: the millions of baby boomers now experiencing their first hot flashes. What Wilson didn't appreciate, but what today's women should know, is that, like every other magic potion, this one has a dark side. To gain the full benefits of estrogen, a woman must take it not only at menopause but also for decades afterward. It means a lifetime of drug taking and possible side effects that include an increased risk of several forms of cancer. That danger was underscored last week by a report in the New England Journal of Medicine reaffirming the long-suspected link between estrogen-replacement therapy and breast cancer. Weighing such risks against the truly marvelous benefits of estrogen may be the most difficult health decision a woman can make. And there's no avoiding it.

As research reveals the pros and cons of estrogen, the therapy's popularity has flowed and ebbed like some sort of national hormonal cycle. Wilson's book did wonders for the sale of Premarin (a form of estrogen made from -- and named for -- a pregnant mare's urine). But estrogen use plummeted after 1975, when studies revealed that women taking the hormone had up to a 14-fold increased risk of uterine cancer. Reports of a 30% increased risk of breast cancer scared away many others.