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.”
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.
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.