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Estrogen Study Lead Researcher on Risks, Benefits of Hormone-Replacement Therapy

April 6, 2011 at 6:12 PM EST
Once a popular treatment for menopause symptoms, hormone-replacement therapy had come under scrutiny for raising the risk of certain diseases, but a new study found a reduced risk of breast cancer and other benefits for some women. Jeffrey Brown discusses the latest findings with Dr. Andrea LaCroix, the study's lead author.
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JIM LEHRER: Now, the latest findings on estrogen for women and what they need to know.

Jeffrey Brown has our update.

JEFFREY BROWN: Once a popular treatment for women dealing with symptoms of menopause, hormone replacement therapy has come under heightened scrutiny in the last decade, with profound implications for its use.

A 2002 study from the Women’s Health Initiative found that use of the combination estrogen and progestin therapy can put women at greater risk for breast cancer, stroke and heart disease.

Now a new study from the same source and published in “The Journal of the American Medical Association” focuses on women who’ve had hysterectomies and as a result used only estrogen. It found some benefits, including a reduced risk of breast cancer and said the risk of stroke declined after women stopped taking the drug.

We walk through the findings with Dr. Andrea LaCroix, lead author of the study. She’s an epidemiologist at the Fred Hutchinson Cancer Research Center in Seattle.

Dr. LaCroix, just to establish briefly where things stand as women begin to digest this new study, what’s happened to the use of hormone therapy since that 2002 report on the combination therapy?

DR. ANDREA LACROIX, Fred Hutchinson Cancer Research Center: What’s happened in the United States is that the numbers of women using hormone therapy have declined quite a bit since 2002.

JEFFREY BROWN: All right. So, now, explain what this new study was looking at. Why specifically was it focused only on women who’d had hysterectomies?

DR. ANDREA LACROIX: Well, we started two hormone therapy trials back in the early ’90s, because we believed that — at the time, based on the totality of the evidence, we believed that taking estrogen might prevent major chronic conditions in postmenopausal women, like heart disease, and like hip fracture, and like colorectal cancer. And we were concerned about a possible increased risk of breast cancer.

So, we started both hormone therapy trials at the same time. The one we’re reporting on today in women with a past hysterectomy for estrogen alone was a separate trial, because women who haven’t had a hysterectomy, who have an intact uterus, cannot take estrogen alone without experiencing a greatly increased risk of uterine cancer.

So they have to take estrogen plus progestin if they take hormone therapy. Women with prior hysterectomy can take estrogen alone.

JEFFREY BROWN: All right. So, what does this new study tell you? What’s the key findings here?

DR. ANDREA LACROIX: Well, the key findings of this study are — there are, like, four main findings.

The first one is what happens when you stop taking hormone therapy? These women took estrogen alone for an average of six years. And after they stopped, we saw the increased risk of stroke and blood clots in the legs and lungs go down. We also saw the benefit on hip fracture slowly go away.

The second major finding that we saw was a decreased risk of breast cancer. During the intervention part of the trial, when they were still taking their pills, there was a suggestion that breast cancer rates were lower in the women taking estrogen vs. placebo. And when we followed these women for another four years, that decreased risk of breast cancer persisted, so that, over the entire follow-up period, we saw a 23 percent decreased risk of breast cancer that has now become statistically significant.

The third finding is that the risks and benefits of hormone therapy differ importantly by age for several types of chronic disease, heart attacks, colorectal cancer, death and then overall chronic diseases are lower among women taking hormone therapy in their 50s compared to placebo, but among women in their 70s, they actually had higher rates of all these conditions if they were taking estrogen alone vs. placebo.

And the last thing I would say that this paper does is it greatly distinguishes estrogen alone from estrogen plus progestin in terms of the overall risks and benefits for postmenopausal women.

JEFFREY BROWN: So — so, if you take those four findings, what do you tell patients now? For women in this particular category, does it suggest that short-term use of estrogen only is OK for them?

DR. ANDREA LACROIX: It suggests, in the 50s, that women can be very reassured that, if they decide to take hormone therapy for relief of menopause symptoms or for other reasons, that they’re not going to have an increased risk of breast cancer; they’re not going to have more heart attacks. In fact, their risks of those outcomes might be lower.

They’re not going to have more deaths. Their risk of death might be lower. And it suggests, for women in their 70s, that starting estrogen has some serious consequences in terms of increasing their risks.

JEFFREY BROWN: The breast cancer, I gather that it’s not at all clear why estrogen alone, estrogen treatment alone, would lower breast cancer risks, or how much to read into that at this point.

I was reading a lot of the study and the commentary on it. And it said it was — it provoked — it will provoke a lot more research.

DR. ANDREA LACROIX: Exactly, the kind of research our country needs to fund, to take off on your previous segment.

The decreased risk of breast cancer, there have been some preclinical and clinical studies that say that, after the cells in the breast get used to not having estrogen from your ovaries, that it’s possible that, if estrogen is reintroduced, like it was in this clinical trial for postmenopausal women, that the estrogen might actually inhibit tumors growing in the breast issue once this involution in the breast cells has occurred postmenopausally.

But we need to know a lot more about that. And I think it’s very exciting.

JEFFREY BROWN: And let me just ask you very briefly, so for the majority of women, perhaps two-thirds of women, who are not in this category, does this change anything? Do they go to their doctors now and ask new questions, or — or status quo?

DR. ANDREA LACROIX: For women who still have their uterus, there are a whole other set of findings that they can use to decide about hormone therapy.

The picture after stopping estrogen plus progestin was quite a bit more risky than the picture that we’re publishing in “JAMA” today. And for women with a uterus, I think they need to pay attention to that whole other trial on estrogen plus progestin.

JEFFREY BROWN: All right. All right, Dr. Andrea LaCroix, thank you very much.

DR. ANDREA LACROIX: Thank you.