Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

WHI follow-up study: Risks of long-term hormone therapy continue to outweigh benefits

05.03.2008
WHI follow-up study confirms health risks of long-term combination hormone therapy outweigh benefits for postmenopausal women

New results from the Women's Health Initiative (WHI) confirm that the health risks of long-term use of combination (estrogen plus progestin) hormone therapy in healthy, postmenopausal women persist even a few years after stopping the drugs and clearly outweigh the benefits.

Researchers report that about three years after women stopped taking combination hormone therapy, many of the health effects of hormones such as increased risk of heart disease are diminished, but overall risks, including risks of stroke, blood clots, and cancer, remain high. The WHI is sponsored by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH).

Results of the WHI three-year follow-up study of the estrogen-plus-progestin clinical trial are published in the March 5, 2008, issue of the Journal of the American Medical Association.

"The good news is that after women stop taking combination hormone therapy, their risk of heart disease appears to decrease," noted Elizabeth G. Nabel, M.D., NHLBI director. "However, these findings also indicate that women who take estrogen plus progestin continue to be at increased risk of breast cancer, even years after stopping therapy. Today's report confirms the study's primary conclusion that combination hormone therapy should not be used to prevent disease in healthy, postmenopausal women."

The FDA recommends that hormone therapy never be used to prevent heart disease, and, when hormone therapy is used for menopausal symptoms, it should only be taken at the smallest dose and for the shortest time possible.

The new findings are from a follow-up study of 15,730 postmenopausal women with an intact uterus, ages 50 to 79 years (average age of 63) at enrollment, who participated in the WHI estrogen-plus-progestin clinical trial. Participants were randomly assigned to receive a combination of estrogen (0.625 milligrams of conjugated equine estrogens per day) plus progestin (2.5 mg of medroxyprogesterone acetate) or placebo (inactive pill). The main estrogen-plus-progestin study was stopped in 2002 after an average of 5.6 years of treatment due to an increase in breast cancer. Women on combination hormone therapy were also at increased risk of stroke, blood clots, and heart disease, while their risk of colorectal cancer and hip fractures was lower, compared to women who did not take hormone therapy.

The follow-up study began in July 2002 after women in the study were instructed to stop taking combination hormone therapy, and continued through March 2005, with participants followed for an average of 2.4 years. All study participants were examined at least once a year by a WHI clinician and received an annual breast examination and mammogram, with biopsies performed as needed. During the follow-up study, the numbers of heart attacks, strokes, and blood clots were not significantly different between the two groups (overall, 343 cardiovascular events among those who initially received hormone therapy versus 323 among those who did not). In addition, the number of deaths was not significantly different (233 women who had been in the hormone therapy group died, versus 196 women who had been in the placebo group).

"After being on combination hormone therapy for several years, the women's risk of cardiovascular disease was significantly higher – from a 29 percent increase in heart attacks to a 41 percent increase in strokes and nearly twice the risk of serious blood clots – compared to the women who did not take hormones," said Michael S. Lauer, M.D., director of the NHLBI Division of Prevention and Population Sciences. "While it is reassuring that heart attack risk decreased and that the risks for stroke and blood clots did not grow after the women stopped taking hormones, this study provides further evidence that five years of combination hormone therapy is harmful. All the accumulated risks do not simply disappear."

The study also found that other effects of combination hormones, such as decreased risk of colorectal cancer and hip fractures, also stopped when therapy ended.

"We continue to encourage women to use hormones only if needed for menopausal symptoms, and for the shortest time possible, and to adopt and maintain a healthy lifestyle, that is, engage in regular physical activity, maintain a healthy body weight, consume a diet low in saturated fat, and to not smoke, to reduce their risks of cardiovascular and other chronic diseases," said Marcia Stefanick, Ph.D., professor of medicine at Stanford University, Stanford, Calif., and a coauthor of the paper, as well as chair of the WHI Steering Committee. She added that women should know their cholesterol and blood pressure levels and other health risks and take preventative measures, as needed.

In contrast to the other effects, the risk of breast cancer continued at a rate similar to that seen during treatment. Women who had stopped taking estrogen plus progestin were about 27 percent more likely to develop breast cancer than the women who didn’t take hormones during the study, with 79 women in the post-treatment group developing breast cancer during the three-year follow-up study, compared to 60 women in the non-treatment group.

"The hormones’ effects on breast cancer appear to linger," noted Leslie Ford, M.D., associate director for clinical research in the Division of Cancer Prevention of the NIH's National Cancer Institute. "These findings reinforce the importance of women getting regular breast exams and mammograms, even after they stop hormone therapy."

Researchers also report a 24 percent increased risk of developing any form of cancer among women who had been in the treatment group. Overall, there were 63 more diagnoses of cancer during the follow-up study, or three per 1,000 participants per year, among women who had taken combination hormone therapy compared to women who did not take hormones during the study (281 diagnoses compared to 218). A more detailed analysis on the cancer findings is underway.

"The continued increased risk of breast cancer clearly plays a role in the increased overall risk of cancer years after stopping long-term estrogen plus progestin therapy, and it is important that we continue to follow these women," added Stefanick, noting that the new results provide further evidence that the health risks of long-term combination hormone therapy outweigh the benefits.

The WHI is a major, 15-year research program designed to address the most frequent causes of death, disability, and poor quality of life in postmenopausal women: cardiovascular disease, cancer, and osteoporosis. The principal findings from the two WHI hormone therapy trials, which studied 27,347 postmenopausal women on estrogen plus progestin, estrogen-alone, or placebo, found that the overall risks of long-term use of hormone therapy outweigh the benefits. Both of these trials were stopped early because of increased health risks and failure to prevent heart disease, a key question of the studies.

NHLBI Communications Office | EurekAlert!
Further information:
http://www.nhlbi.nih.gov

More articles from Health and Medicine:

nachricht Vanishing capillaries
23.03.2017 | Technische Universität München

nachricht How prenatal maternal infections may affect genetic factors in Autism spectrum disorder
22.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

Inactivate vaccines faster and more effectively using electron beams

23.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>