Some women take a short break from using postmenopausal hormone therapy before getting their breasts screened for cancer with mammography. They hope to lower their risk of being called back afterward for unnecessary extra breast imaging.
But taking a short break from hormones doesn't actually work for this purpose, according to the first large-scale randomized controlled trial to address the question. The READ (Radiological Evaluation and Breast Density) trial of more than 1,700 Group Health women is in the June 2, 2009 Annals of Internal Medicine.
"Postmenopausal hormones make breasts denser—like young women's breasts—and make mammograms harder to 'read,'" explained Diana S.M. Buist, PhD, MPH, an associate investigator at Group Health Center for Health Studies in Seattle. This raises the chance of having a "false-positive." That means women are called back ("recalled") for more testing, only to learn they have no breast cancer after all.
"False-positives account for a quarter of the overall costs of mammography in the United States," Buist said. Previous evidence showed stopping hormones could improve mammography, which led some clinicians to suggest stopping briefly before a mammogram. But there was no evidence of how long women needed to stay off hormones for their mammograms to improve. "We thought it was important to see if stopping hormones for one or two months really did make any difference in clinical outcomes," she said. "And we also wanted to make sure that it didn't cause any harm."
It didn't work in practice, according to the READ trial. The trial's three groups did not differ significantly in what proportion was called back for more tests after screening mammography. Of the women (aged 45-80) who stayed on hormone therapy, 11.3% were called back for more tests, compared to 12.3% and 9.8%, respectively, of those who stayed off hormones for one or two months. Taking a break from hormone therapy was not without harm: increasing the women's menopause symptoms. But there was also some benefit—making their breasts slightly less dense.
What does breast density mean? Breast tissue is composed mainly of milk glands and fat. A breast is dense if it consists of more milk glands than fat. Dense breast tissue, like milk glands, is denser and looks white on an X-ray, making tumors harder to see. That's why any tumors are harder to detect on mammograms of denser breasts than on those of less dense breasts. Breast density tends to decline with age, but individual women differ in the density of their breasts. Aside from age, having dense breasts is the biggest risk factor for breast cancer.
"We really hoped to find that a brief break in hormone therapy would lower false-positives and remove unnecessary costs and anxiety by improving mammography," Buist said. "And we were disappointed to find that it didn't. But we'll keep trying to find ways to reduce recall rates for women—in hopes of making mammography more effective and ensuring women have to go through the least amount of testing and radiation that's necessary."
The READ trial is part of Group Health's ongoing research on the comparative effectiveness of tests, treatments, and preventive actions—and figuring out which ones work and which don't in real clinical settings. "These types of studies are being called for increasingly as America and policy makers think about how to reform our health care system," Buist said. "Studies like this are important for making sure that we are basing medicine on evidence and providing the most effective health care."
"This study does not change our clinical message to doctors or patients about hormone therapy," said Buist.
"After our trial, as before it, women should engage in shared decision making with their doctors about whether or not to take hormones for their menopause symptoms—and if so, for how long," added Buist's co-author Susan D. Reed, MD, MPH. "Even women who find hormone therapy helps their symptoms should reassess yearly whether to continue hormone therapy," added Reed, a professor of obstetrics and gynecology at the University of Washington and an affiliate investigator at Group Health Center for Health Studies.
The Department of Defense funded the READ trial, which enrolled women from Group Health's Breast Cancer Screening Program.
Buist and Reed's READ trial co-authors were Juleann C. Gandara, MD, of Group Health; and Katherine M. Newton, PhD; Erin J. Aiello Bowles, MPH; Melissa L. Anderson, MS; E. Dawn Fitzgibbons, MPH; and Deborah Seger of Group Health Center for Health Studies.
Group Health Center for Health Studies
Founded in 1947, Group Health Cooperative is a Seattle-based, consumer-governed, nonprofit health care system that coordinates care and coverage. Group Health Center for Health Studies is Group Health's research institute. For 25 years, the Center has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems. Government and private research grants provide its main funding.
Rebecca Hughes | EurekAlert!
Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Life Sciences
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences