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!
Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences