Pregnancy at a relatively young age reduces the risk of breast cancer over the long term, but epidemiological studies have found that women are at an increased risk for breast cancer during pregnancy and for up to 10 years after giving birth, said Debra Tonetti, associate professor of pharmacology and lead researcher on the study.
These pregnancy-associated breast cancers also carry an unusually high risk of spreading to nearby organs and for lethality as compared to breast cancers in women who have never been pregnant, she said.
Tonetti and her research team examined the level of expression of 64 genes in tissue from benign breast biopsies and breast-reduction surgeries at the University of Illinois Medical Center at Chicago. The women, who were between the ages of 18 and 45, were divided into three categories: those who had never been pregnant, those who had been pregnant within the past two years, and those who had been pregnant five to 10 years previously.
The set of examined genes included genes known to be related to immunity and inflammation, extracellular matrix remodeling, angiogenesis (the growth of new blood vessels vital to wound healing) or hormone signaling.
Twenty-two percent of the examined genes showed significant difference in expression in the breast tissue of women who had never given birth compared with those who had. Inflammation-related genes, as a class, were more active in women who had borne a child. Involution -- the process by which the breast returns to normal following lactation -- could be a cause of the inflammation, she said.
"Our results showed an increase in immune/inflammatory activity in the post-pregnant breast," Tonetti said. "Interestingly, this response was not limited to the recently pregnant group, but also characterized more distant pregnancies as well."
A surprising finding was evidence of a protective effect of pregnancy as well, since the expression of many hormone and growth factor signaling genes suggests protection. These findings indicate that a balance between high risk inflammatory and protective hormone signaling gene expression may ultimately determine a woman's individual breast cancer risk, she said.
The researchers were not only interested in determining whether pregnancy and involution are associated with gene expression changes in the normal breast, but whether such changes stay for a short period of time or are permanent, Tonetti said.
The study is among the first to use samples from normal breast tissue to determine whether there is a time-dependent effect on breast cancer risk, she said.
The results will help understand the mechanisms behind pregnancy-associated breast cancer and will indicate potentially effective prevention strategies for women at high risk, such as use of anti-inflammatory agents. In addition, more effective therapeutic approaches may be developed based on the specific molecular pathways involved, Tonetti said.
The findings are published in the March issue of the journal Cancer Prevention Research. The study was funded through a grant from Avon Products Foundation.
Other authors, all from UIC, include Szilard Asztalos and Megan Hayes of the department of biopharmaceutical sciences; Peter Gann, Larisa Nonn and Elizabeth Wiley of the department of pathology; Craig Beam of the department of epidemiology and biostatistics; and Yang Dai of the department of bioengineering.
Sam Hostettler | EurekAlert!
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research