The same team of researchers from UC San Francisco and Seattle-based Group Health Research Institute recently reported similar results for older women ages 66 to 89.
By contrast, women in their 40s with extremely dense breasts who undergo biennial mammography are more likely to have advanced-stage and large tumors than women who undergo annual mammography – but annual mammograms also resulted in more false positives, according to the new study from the Breast Cancer Surveillance Consortium (BCSC), the largest available screening mammography dataset in the United States. Having dense breasts means it is difficult for X-rays to pass through the breast tissue.
“Increasing age and high breast density are among the strongest risk factors for the disease,” said senior author Karla Kerlikowske, MD, a professor of medicine at UCSF and a physician at the UCSF-affiliated San Francisco VA Medical Center.
Weighing the Risks and Benefits of Screening
Kerlikowske and other BCSC researchers reported in 2012 that risk factors may inform individual decisions that women make with their doctors about when to start breast cancer screening and how often to repeat it. For instance, a family history of breast cancer raises the likelihood of developing the disease but it does not increase the chances of advanced-stage tumors or large tumors.
“These individual decisions involve evaluating the balance between the benefits of screening – detecting cancer early – and the potential harms, such as false positives among healthy women,” Kerlikowske said. “Some people who are at higher risk of disease may be more willing than those at lower risk to accept such potential harms of screening.”
False positives mean that women without cancer are called back for more testing, including biopsies, ultrasounds and more mammograms.
“For women 50 to 74 years old with dense breasts who are cancer free, we estimated that more than half will be recalled for additional mammography at least once over the course of 10 years of annual screening,” said study co-author Rebecca A. Hubbard, PhD, an assistant investigator at Group Health Research Institute who is also at the University of Washington School of Public Health. “Screening every other year decreases this risk by about a third. The risk of false-positive results is even higher for women who begin annual screening at age 40.”
National Guidelines for Mammograms
When the U.S. Preventive Services Task Force updated its breast cancer screening guidelines in 2009, it advised women to make individual decisions with their doctor. But for average-risk women, these guidelines advised screening mammography every two years for women ages 50 to 74. The guidelines recommended that women in their 40s consider their personal values regarding the benefits and harms and then decide when to begin regular screening. The Task Force deemed evidence on risk factors other than age to be weak at that point.
The new study was designed to explore other risk factors for breast cancer, beyond age. Extremely dense breasts and taking combination hormone therapy (with estrogen and progestin, although not with estrogen alone) had already been shown to raise women’s rates of advanced-stage or large tumors. The new study adds to this evidence by showing regardless of breast density or hormone use, screening every other year did not raise the likelihood of detecting advanced-stage or large tumors, compared to yearly screening.
Approximately 12 to 15 percent of women in their 40s – and approximately 3 to 6 percent of those ages 50 to 74 – have extremely dense breasts.
How does a woman know if her breasts are dense or extremely dense?
“It’s a “Catch- 22”,” said co-author Diana L. Miglioretti, PhD, a senior investigator at Group Health Research Institute who is also at the University of California at Davis. “The only standard way to determine your level of breast density is to get a mammogram. But unless your breasts are extremely dense and you have other strong risk factors, the data don’t necessarily support your starting screening mammograms before age 50.”
The study was supported by grants from the National Cancer Institute of the National Institutes of Health (R03 CA150007, RC2 CA148577, and P01 CA107584); the National Cancer Institute-funded Breast Cancer Surveillance Consortium (U01 CA 63740, CA86076, CA86082, CA63736, CA70013, CA69976, CA63731, and CA70040. Several state public health departments and cancer registries throughout the United States supported, in part, the collection of cancer data used in this study.
Co-authors from Group Health Research Institute are: Karen J. Wernli, PhD, Ellen S. O’Meara, PhD, and Weiwei Zhu, MS; from UCSF: Dejana Braithwaite, PhD; from the University of Vermont: Berta Geller, EdD, and Kim Dittus, MD, PhD.
Elizabeth Fernandez | 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
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
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....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Ecology, The Environment and Conservation
21.08.2018 | Life Sciences
21.08.2018 | Power and Electrical Engineering