The researchers found a 28 percent reduced risk of developing breast cancer in women whose breasts decreased in density, as seen from two different mammograms taken an average of six years apart, compared to women whose breast density did not change.
Two measures of breast density may, therefore, provide additional information for assessing breast cancer risk, says the study's lead investigator, Celine Vachon, Ph.D., an associate professor of epidemiology. Dr. Vachon adds, however, that this information is not ready for use in clinical practice to inform breast cancer risk. "Replication of these findings in other studies will be important," she says. "Also, improved and standardized measurements of breast density are needed for the assessment of changes in density."
The current assessment available in most clinical settings is BI-RADS, Breast Imaging-Reporting and Data System, which is relatively unsophisticated when it comes to measuring breast density and was not intended for this purpose, Dr. Vachon says. "There is a lot of ongoing work aimed at improving measures of density, so that situation should change," she adds.
This study was drawn from the Mammography Health Study, which enrolled 19,924 women who were free of breast cancer, had screening mammograms performed at Mayo Clinic between 2003 and 2006 and resided in Minnesota, Iowa and Wisconsin. From this large group, the researchers selected participants who had at least one additional screening mammogram prior to enrollment, and then looked at clinic and tumor registries in the three Midwestern states to determine if any of these women developed breast cancer after enrolling in the study.
Measures of mammographic density were obtained from the two mammograms, an average of six years apart, for the approximately 1,900 women randomly sampled from the cohort, and from all 219 individuals who were diagnosed with breast cancer during follow-up. In the cancer-free group, 38.6 percent of women had a decrease in breast density, 50.4 percent stayed the same, and 11 percent showed an increase in breast density. In women who developed breast cancer, the percentages were 37, 51 and 12, respectively.
Women who developed breast cancer were less likely to experience a decrease in density in a second mammogram, says Dr. Vachon. After adjusting for other potential factors that contribute to breast cancer development, such as age, body mass index, postmenopausal hormones, postmenopausal status, in addition to baseline breast density, the researchers found that women who decreased one BI-RADS category or more over an average of six years were at 28 percent reduced risk of developing breast cancer, compared to women whose density was unchanged.
"We know that breast density can change with time, as evidenced by decreases seen with women going through menopause or using the breast cancer preventive drug tamoxifen and increases seen with postmenopausal hormone therapy use. Our results suggest that decreases in density may translate to decreased breast cancer risk," Dr. Vachon says.
The study was funded by grants from the National Institutes of Health.About Mayo Clinic
Karl Oestreich | EurekAlert!
Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
On track to heal leukaemia
18.01.2017 | Universitätsspital Bern
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy