Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Negative BRCA testing may not always imply lowered breast cancer risk

27.11.2013
Women who are members of families with BRCA2 mutations but who test negative for the family-specific BRCA2 mutations are still at greater risk for developing breast cancer compared with women in the general population, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Women with certain mutations in their BRCA1 or BRCA2 genes are at increased risk for breast cancer. However, if a woman who comes from a BRCA family tests negative for her family-specific BRCA mutation, her risk for breast cancer is considered to be the same as someone in the general population, according to the National Cancer Institute. This study, however, suggests that it may not always be true.

"We found that women who test negative for family-specific BRCA2 mutations have more than four times the risk for developing breast cancer than the general population," said Gareth R. Evans, M.B.B.S., M.D., M.R.C.P., F.R.C.P., honorary professor of medical genetics and cancer epidemiology at the Manchester Academic Health Science Center at the University of Manchester in the United Kingdom. "We also found that any increased risk for breast cancer is largely limited to BRCA2 families with strong family history and other genetic factors.

"It is likely that these women inherit genetic factors other than BRCA-related genes that increase their breast cancer risk," he explained. "About 77 single nucleotide polymorphisms [SNPs—genetic variations that can help track the inheritance of disease genes within families] are linked to breast cancer risk. Identification of additional SNPs is necessary to understand why some of the BRCA-negative women from BRCA families are at higher risk."

The authors note that specialists should use caution when stating that a woman's breast cancer risk is the same as that of the general population following a negative test, because it may not be true for some women who come from BRCA2 families with a strong family history.

Evans and colleagues used data from the M6-Inherited Cancer in England study, which has screened families of individuals with breast and/or ovarian cancer for mutations in BRCA1 and 2 since 1996. Details on affected individuals, and all tested and untested relatives, were entered into a Filemaker Pro-7 database. From 807 BRCA families, the researchers identified 49 women who tested negative for the family-specific BRCA mutation, but subsequently developed breast cancer. The researchers called these women "phenocopies."

Of the 49 phenocopies identified, 22 were among 279 women who tested negative from BRCA1 families, and 27 were among 251 women who tested negative from BRCA2 families. When the researchers stratified the phenocopies based on their age (30-39, 40-49, 50-59, and 69-80), they found that in each age range there were about twice as many cases of breast cancer as would have been expected from the general population.

Next, to conduct risk analyses, Evans and colleagues calculated the "observed versus expected ratio" (O/E), a ratio of observed risk for breast cancer in BRCA-negative women from BRCA families, versus the risk expected for any woman in the general population.

They found the O/E for phenocopies from BRCA1 families was not substantially higher than that of the general population; however, the O/E for phenocopies from BRCA2 families was 4.57, leading them to conclude that the more than fourfold increased risk for breast cancer among BRCA-negative women is largely limited to BRCA-negative women from BRCA2 families.

When the researchers considered the date of predictive testing (the date on which BRCA testing was done for an individual) instead of the date of family ascertainment (the date the first family member of the individual was referred to genetic service), O/E dropped from 4.57 to 2.01, "because there is less follow-up in the predictive test group from time of testing and we may be unaware of breast cancers that have occurred in the near past," explained Evans.

To interview Gareth Evans, please contact Peppermint Soda at jess.gorton@peppermintsoda.co.uk or 0161-941-4252. For all other inquiries, please contact Jeremy Moore at jeremy.moore@aacr.org or 215-446-7109.

This study was funded by the National Institute for Health Research. The authors declare no conflict of interest.

Follow the AACR on Twitter: @AACR

Follow the AACR on Facebook: http://www.facebook.com/aacr.org

About the American Association for Cancer Research

Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 34,000 laboratory, translational, and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis, and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 18,000 attendees. In addition, the AACR publishes eight peer-reviewed scientific journals and a magazine for cancer survivors, patients, and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the scientific partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration, and scientific oversight of team science and individual grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit http://www.AACR.org.

Jeremy Moore | EurekAlert!
Further information:
http://www.aacr.org

More articles from Health and Medicine:

nachricht Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>