Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Menopause Health Center

Font Size

Menopause Hormone Therapy: 'Safe' Time?

New Studies Probe Timing of Hormone Replacement Therapy and Breast Cancer Risk

New Findings on Hormone Replacement Therapy

The two new studies agree on four things:

1. The long-term breast cancer risk from estrogen-plus-progestin therapy is real. Rowan Chlebowski, MD, PhD, who worked on The New England Journal of Medicine study, says that risk has been characterized as being "small," but at least 20,000 cases of breast cancer per year in the U.S. may be due to hormone therapy. "It's not a hypothetical number, something that never happens," Chlebowski tells WebMD.

2. Quitting hormone therapy cuts breast cancer risk. The increased breast cancer risk from hormone replacement therapy appears to end about two years after quitting hormone therapy. That's "good news," Chlebowski tells WebMD. In the WHI data, "it looked like the risk starts to go down right away. And after between one and two years, it looks like pretty much like that risk is gone," says Chlebowski, who works at the Los Angeles Biomedical Research Institute at the Harbor-UCL Medical Center.

Eugenia Calle, PhD, who worked on the study published in Cancer, agrees. "For women who've stopped using estrogen plus progestin, our data suggest that their risk for breast cancer will go back down in a fairly short period of time," says Calle, who recently retired as the American Cancer Society's vice president of epidemiology.

3. Mammography rates don't explain the drop in breast cancer after quitting hormone replacement therapy. Using WHI data, Chlebowski's team confirmed that breast cancer rates really did drop after women quit hormone replacement therapy; it wasn't because of a change in mammography use.

4. Breast cancer risk is greater with estrogen-plus-progestin than estrogen alone. "We do not have evidence from the WHI clinical trial that estrogen increases breast cancer. It's the combination of estrogen and progestin" that's the issue, Marcia Stefanick, PhD, tells WebMD. Stefanick works at the Stanford Prevention Research Center and was one of Chlebowski's colleagues in reviewing the WHI data.

Calle puts it this way: "Estrogen plus progestin is considerably worse in terms of breast cancer risk than estrogen alone, and we've known that for some time."

Just taking estrogen probably isn't a solution for women who still have their uterus, because doing so would raise their risk of uterine and endometrial cancer. Women who've had a hysterectomy don't have to worry about that.

"We had a huge increase in endometrial cancer back in the '70s that was reported when women were taking just estrogen if they had a uterus. So I don't think very many people would want to go back to unopposed estrogen [estrogen without progestin] as the approach," says Stefanick.

But the studies have their differences, too.

Today on WebMD

woman walking outdoors
How to handle headaches, night sweats, and more.
mature woman holding fan in face
Symptoms and treatments.
woman hiding face behind hands
11 ways to keep skin bright and healthy.
Is it menopause or something else?
senior couple
mature woman shopping for produce
Alcohol Disrupting Your Sleep
mature couple on boat
mature woman tugging on her loose skin
senior woman wearing green hat
estrogen gene

WebMD Special Sections