A break from hormone therapy doesn't improve mammograms

June 1, 2009

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 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 , 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 symptoms. But there was also some benefit—making their breasts slightly less dense.

What does 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 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.

Source: Group Health Cooperative Center for Health Studies

Related Stories

Recommended for you

Lung cancer triggers pulmonary hypertension

November 17, 2017
Shortness of breath and respiratory distress often increase the suffering of advanced-stage lung cancer patients. These symptoms can be triggered by pulmonary hypertension, as scientists at the Max Planck Institute for Heart ...

Researchers discover an Achilles heel in a lethal leukemia

November 16, 2017
Researchers have discovered how a linkage between two proteins in acute myeloid leukemia enables cancer cells to resist chemotherapy and showed that disrupting the linkage could render the cells vulnerable to treatment. St. ...

Computer program finds new uses for old drugs

November 16, 2017
Researchers at the Case Comprehensive Cancer Center at Case Western Reserve University School of Medicine have developed a computer program to find new indications for old drugs. The computer program, called DrugPredict, ...

Pharmacoscopy improves therapy for relapsed blood cancer in a first clinical trial

November 16, 2017
Researchers at CeMM and the Medical University of Vienna presented a preliminary report in The Lancet Hematology on the clinical impact of an integrated ex vivo approach called pharmacoscopy. The procedures measure single-cell ...

Wider sampling of tumor tissues may guide drug choice, improve outcomes

November 15, 2017
A new study focused on describing genetic variations within a primary tumor, differences between the primary and a metastatic branch of that tumor, and additional diversity found in tumor DNA in the blood stream could help ...

A new strategy for prevention of liver cancer development

November 14, 2017
Primary liver cancer is now the second leading cause of cancer-related death worldwide, and its incidences and mortality are increasing rapidly in the United Stated. In late stages of the malignancy, there are no effective ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.