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- Posted Wednesday September 16, 2015
Research discovery leads to potential diagnostic for assessing breast cancer recurrence
By measuring DNA methylation, TGen researchers might determine which patients are at higher risk for relapse or metastases
PHOENIX, Ariz. - Sept. 16, 2015 - Every woman
successfully treated for breast cancer lives with the knowledge
that it could come back. New research published today in the
journal Clinical Epigenetics may lead to a simple blood
test to determine the risk of such recurrence, or the cancer
invading other organs such as the lungs, bone or brain. Such a test
would have profound implications for improving the future treatment
of women with all types of breast cancer, a disease that will
impact one-in-eight women.
Through the study, researchers at the Translational Genomics Research
Institute (TGen) identified 21 DNA hypermethylation hotspots -
gene locations along the 3 billion chemical bases of DNA - with
increased levels of methylation that could indicate the existence
of metastatic breast cancer.
"These findings could lead to a highly sensitive blood-based test
panel - a type of liquid biopsy - which could help improve the care
of women with breast cancer," said Dr. Bodour Salhia, an Assistant
Professor in TGen's Integrated Cancer Genomics Division, and the
study's senior author.
"This 21-gene signature is a potential biomarker that could
indicate patients who are at high risk of cancer recurrence, either
in the breast or elsewhere in the body, and who might benefit from
additional therapy to eliminate the potential of recurrence," Dr.
Salhia said. "This would be critically important information for
oncologists as they consider ongoing treatments post surgery and/or
the completion of each round of chemotherapy."
Biomarkers are indicator molecules, such as proteins or DNA, that
are measurable in blood, body fluids or tissue samples and can be
used to diagnose or measure a particular disease or the effects of
a given treatment.
Using whole-genome sequencing, researchers looked for biomarkers
in the cell-free strands of DNA (cfDNA) circulating in pooled
samples of blood from 40 metastatic breast cancer patients, and
compared them to samples from 40 healthy individuals and 40
disease-free breast cancer survivors.
The findings offered insights that suggest despite the huge
quantity of information gleaned from other gene signatures
currently available, none can precisely predict the clinical course
of an individual, and they rely on the presence of tissue at a
single time point. There are patients deemed high-risk who do very
well with standard therapy and never experience a recurrence, and
patients with low-risk profiles who succumb to the disease.
In contrast, the TGen study identified 21 genes that were
"differentially methylated" - meaning they could have altered
levels of methylation - all of which were consistently higher in
patients with metastatic breast cancer when compared to the levels
in healthy individuals and cancer-free survivors.
"This study is one of the first whole-genome descriptions of
methylation in blood, and the first unbiased study reporting on the
circulating methylome of metastatic breast cancer," said Dr.
Salhia. "There is likely a predictive clinical window of
opportunity to detect microscopic disease before the cancer spreads
throughout the body."
The next step would be to further validate the results using
individual samples.
The study - Whole genome bisulfite sequencing of cell-free DNA
identifies signature associated with metastatic breast cancer
- can be found at http://www.clinicalepigeneticsjournal.com/content/7/1/100.
The study was funded in part by the Marilyn B. Gula Mountains of
Hope Foundation and by SmartPractice.
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About TGen
Translational Genomics Research Institute (TGen) is a Phoenix,
Arizona-based non-profit organization dedicated to conducting
groundbreaking research with life changing results. TGen is focused
on helping patients with neurological disorders, cancer, and
diabetes, through cutting edge translational research (the process
of rapidly moving research towards patient benefit). TGen
physicians and scientists work to unravel the genetic components of
both common and rare complex diseases in adults and children.
Working with collaborators in the scientific and medical
communities literally worldwide, TGen makes a substantial
contribution to help our patients through efficiency and
effectiveness of the translational process. For more information,
visit:www.tgen.org. Follow TGen on Facebook, LinkedIn and Twitter @TGen.
Press Contact:
Steve Yozwiak
TGen Senior Science Writer
602-343-8704
[email protected]