The future of cancer diagnosis and treatment: Liquid biopsies can reveal cancer and more

Some of cancer’s secrets are hiding in patients’ blood. Uncovering
them involves only a simple blood draw.

MD Anderson is taking innovative steps to
maximize the potential of so-called liquid biopsies for the benefit of
our patients.

“Although liquid biopsies for broad clinical use are still in their
infancy, they have the potential to revolutionize cancer care,” says
Stan Hamilton, M.D., division head, Pathology
and Laboratory Medicine.

MD Anderson is pushing this field
forward in many ways. It’s an incredibly exciting time.”

Blood vs. tissue biopsies

Biopsies are critical to the diagnosis and treatment of cancer. In
the past, the only option was collecting tissue from the tumor for
examination. Today, physicians can learn important information about
certain cancers from a tube of blood. And for patients, a quick needle
stick is preferable to a more invasive procedure that can get
complicated depending on the tumor’s size and location.

So why do tissue biopsies anymore?

“Blood can only tell us so much right now, so tissue biopsies remain
the best and sometimes only option to provide the answers we need,”
Hamilton says. “But I’m confident that we’ll be able to use liquid
biopsies more as discoveries continue.”

Unlocking answers

Because cancer cells can release genetic material into the
bloodstream, blood can help us learn earlier if there’s cancer in the
body, before it causes symptoms or grows enough to be seen through
imaging. This is currently most helpful to monitor if cancer has
returned after treatment.

Blood also can reveal genetic information about the cancer that’s
present. Liquid biopsies scan for particular genetic alterations,
aiding in prognosis and suggesting appropriate treatment, including
targeted therapies.

One example is a single-gene test that was developed here based on
work by Gilbert Cote, Ph.D., professor of Endocrine
Neoplasia and Hormonal Diseases, to look for a specific genetic
mutation called RET p.M918T.

It’s a prognostic test for physicians treating medullary thyroid cancer. They’ve learned that
patients with high levels do better on one treatment path and those
with low levels or no mutation do better on another path of treatment.

“The test is helping me guide patients to the most effective
treatment,” says Naifa Busaidy, M.D., associate professor of
Endocrine Neoplasia and Hormonal Diseases.

The speed of the results is another benefit.

“Doing this single-gene test here in our Molecular Diagnostics
Laboratory gives me a result in two or three days, rather than a few
weeks,” Busaidy says.

MD
Anderson
has launched other single-gene tests this year. One
scans for a mutation related to melanoma and colorectal cancer to indicate the amount of
cancer present and monitor the patient’s response to treatment.
Another test scans for a mutation related to lung cancer to see if the cancer fails to
respond to treatment.

Working together

Also this year, MD Anderson formed a
partnership with Guardant Health
to accelerate making
comprehensive liquid biopsies the standard of care in cancer treatment.

Guardant Health will help MD Anderson
build multiple on-site liquid biopsy centers for both standard of care
testing and the pursuit of new discoveries through research testing.

“Unlike the single-gene tests we developed this year, Guardant
offers broad testing and is known for the number of genes it screens,
currently 73. The sensitivity of its test detects mutations even when
there isn’t much cancer DNA present in the blood,” Hamilton says.
“We’ll be creating a unique, MD
Anderson
-only test to include actionable mutations found in our
patient population, especially those in our many clinical trials.”

Another benefit of the partnership is access to Guardant’s
bio-informatics pipeline, says Raja
Luthra, Ph.D.
, professor of Hematopathology and director of our
Molecular Diagnostics Laboratory, where the clinical testing will be performed.

Not only will our patients get tested for mutations and chromosomal
rearrangements in a tailored panel of tests, they will benefit from
the efficiencies of on-site testing.

MD Anderson and Guardant also will work
together to accelerate discoveries to further advance the use of
liquid biopsies.

“This is a paradigm shift for patients with solid tumors,” Luthra
says. “It’s the future, and it’s very gratifying and exciting to be
part of something that’s so positive for patients.”

A longer version of this story originally appeared in
Messenger, MD Anderson’s quarterly
publication for employees, volunteers, retirees and their families.

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