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Research Highlights
Studies under way in VA to advance genomic medicine
April 20, 2008
A review article published in the
March 19 Journal of the American
Medical Association (JAMA) by researchers
from VA and the RAND Corporation has
focused attention on the burgeoning
movement to incorporate genomics—the
use of patients' individual genetic profiles to
customize care—into everyday medical
practice. VA has a rich array of research
projects relating to genomic medicine and
expects to be in the forefront of its widening
implementation.
The authors of the JAMA article, who
synthesized findings from 68 studies, found
that on the whole, health professionals and
the public in the U.S. and other developed
countries are unprepared to make effective
use of genomics to prevent, diagnose or
treat common chronic illnesses such as
diabetes or heart disease.
"Primary care clinicians are on the front
lines of patient care and they are going to
need to be prepared to incorporate genetics
into their practices," said lead author Maren
Scheuner, MD, MPH, of RAND. "Training
and educating the health care workforce
about the role of genetics in their clinical
practice and increasing the size of the
genetics specialty workforce are potential
solutions to the barriers we identified."
The study was funded by VA to inform its
agenda for research on genomic medicine
and to help guide the implementation of
genomic medicine in its health system. The
everyday use of genomic medicine in VA
nowadays is still limited in scope, as in U.S.
health care in general, but the agency has
launched an ambitious research agenda to
iron out the ethical, logistical and scientific
issues that need to be resolved before the
field can expand.
Current policy at VA hospitals and clinics
is to provide whatever genetic tests are
clinically necessary and appropriate.
"In applying that policy on the clinical
side, it means that we normally don’t do any
tests that are not related to the diagnosis or
treatment of patients," says Michael
Brophy, MS, MT (ASCP), associate chief
consultant for VA’s Diagnostic Services
office. “While the individual provider
makes the decision on what tests to order,
those that provide little if any diagnostic
value are generally not ordered in VA."
An example of a genetic test that would
be provided is the test to confirm the
diagnosis of hemochromatosis, a hereditary
condition in which iron builds up in the
body. Another example is ApoE
genotyping, used to predict a patient’s
response to cholesterol-lowering statin
drugs or to help diagnose Alzheimer’s
disease. VA doctors also commonly use
genetic tests to help diagnose breast, colon
and other cancers.
Tests whose clinical value is debatable
are less likely to be offered in VA, says
Brophy. For example, about five percent of
patients carry a gene that makes them very
sensitive to the blood thinner warfarin, sold
as Coumadin. But offering the test appears
to have little impact on patient care and outcomes. Brophy: "Most
of the clinicians just didn’t feel it was going to make much
practical difference when looked at from the perspective of real
clinical outcomes. Because if you start patients on a low dose as
you’re supposed to, and then adjust their therapy upward, the
genetic predisposition, when considered along with the other
variables, is generally not as relevant. It’s only one of many factors
that determine the appropriate dose."
Next decade may bring dramatic progress
Ron Przygodzki, MD, associate director for genomic medicine
with VA’s Office of Research and Development, agrees that the test
for warfarin "is a good step forward in the right direction" but not
yet a magic bullet for physicians.
Similarly, he points out that much of the predictive DNA testing
purchased by veterans and other consumers through various
Internet sites offers little practical benefit. He says most of the tests
come back with results indicating only a slightly elevated risk for
this or that medical condition, based on a combination of single
nucleotide polymorphisms—genetic variations—that may or may
not be clinically significant. The information is thus unlikely to
affect decisions by patients or their doctors.
"The only thing your physician could tell you, for example, is
that you may be susceptible to diabetes, or obesity," says
Przygodzki. "There are no bona fide studies to get a real answer on
what this really means. Most diseases involve a lot of medical and
lifestyle factors. We can’t put a finger on one thing."
However, he expects the situation to change dramatically over
the next decade as researchers in VA and elsewhere continue to
refine and expand genetic testing and study how to best use the
results to improve care. A case in point: Katherine Meyer-Siegler,
PhD, a research chemist at the Bay Pines (Fla.) VA Medical Center,
recently found that genetic variations associated with a protein
called macrophage migration inhibitory factor may signal an
increased risk for prostate cancer recurrence. Findings such as
these could eventually make an important difference for patients
and doctors deciding on a treatment approach.
Survey of veterans to help guide efforts
Aside from biomedical advances, laying the groundwork for the
expansion of genomic medicine involves thorny ethical issues. For
example, how are DNA samples stored and for how long? How is
the information "de-identified," and who has access to it? DNA
samples collected as part of VA research studies are handled
according to strict and clearly defined rules. But if DNA testing
becomes a much bigger part of routine clinical care, VA will need
additional policies governing its use.
Tackling such issues is one of the jobs of VA’s 13-member
Genomic Medicine Advisory Committee, which includes genetics
experts and representatives from veterans’ groups. The group was
formed in 2006 to advise VA on scientific and ethical issues related
to the establishment, development and operation of a genomic
medicine program.
Additional guidance is expected from an Internet-based survey of
about 900 veterans now being conducted for VA by the Genetics and
Public Policy Center (GPPC) at Johns Hopkins University. The
survey was designed based on results from focus groups held with
veterans nationwide over the past year. GPPC recently conducted a
similar survey of the general public for the National Human Genome
Research Institute.
Sumitra Muralidhar, PhD, a scientific program manager with
VA's Office of Research and Development, says the survey should
provide important answers to help guide VA’s eventual
implementation of genomic medicine.
According to Muralidhar, "The survey questions generally relate
to what aspects of the genomic medicine program veterans are
optimistic about, what they are concerned about, and what their
expectations are—for example, whether they think the program
will benefit their healthcare, whether they would expect
compensation for participation, what types of research their genetic
information should be used for, who should have access to their
samples and data, and what their expectations are with regard to
privacy and security of their genetic information."
Adding genetic data into the electronic
health record
Przygodzki notes that VA researchers are also working with
outside experts to examine issues such as how to merge genetic
information into VA’s innovative electronic health record, which
serves as an invaluable tool for VA clinicians and researchers.
As reflected in the VA-RAND study in JAMA, adding genetic
information to health records is just one of many infrastructure
issues that will need to be resolved before genomics can be used
more widely in VA. "The technology is coming around," says
Przygodzki, "but we need to create the structures for educating
patients, physicians, and caregivers. We
also need to make sure that we put the
information into the medical file so
clinicians and researchers can use it
appropriately and effectively."
First and foremost, he says, "We have
to protect the veterans we care for and
handle their genetic information in a way
that’s safe and beneficial for them."
This article originally appeared in the April-May 2008 issue of VA Research Currents.
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