New York – New Blood Test Offers Advances In Cancer Biopsies

New York – A new blood test is being tested in labs across the U.S. that may provide a less invasive cancer biopsy.

Researchers are looking into what they call the liquid biopsy, a blood test that can be used to trace small pieces of DNA in the patient’s blood that could alert a doctor to cancer cells without the traditional CT scan, or in some cases, surgery, to obtain part of the tumor for testing, reports the New York Times (http://nyti.ms/1aKY1bT).

Doctors hope the blood test will show if a treatment is working, and will allow easier and more frequent monitoring of tumors. Currently, the only way to know if a tumor is responding to treatment or developing resistance to treatment is with a biopsy.

The new liquid biopsy could also let doctors stop failing treatments faster, allowing more time to try alternative treatments.
It may take weeks or even months for a scan to show a shrinking tumor; other times, scans showing connective tissue, scars and immune system cells at the site of the tumor can sometimes fool a doctor into thinking the tumor is present when it’s actually gone.

Scientists made a discovery years ago about fetuses that led to the discovery of the test; fetuses give off tiny pieces of DNA into the mother’s bloodstream, leading scientists to discover that growing cells – including tumors – shed fragments of DNA. Cancer researchers then used DNA sequencing to find mutations that serve as indicators for cancers.

Fifth-grade teacher Mary Susan Sabini, of Gardiner, New York, has lung cancer that resisted two chemotherapy attempts and one round of radiation. Doctors monitoring her cancer DNA in her blood saw that the DNA vanished after taking an experimental drug, making doctors think the treatment was working. Weeks later, Sabini began to breathe easier and months later, her CT scan showed that her tumors were shrinking.

A study by the National Cancer Society published in April in The Lancet Oncology involving 126 patients with the most common form of lymphoma found that the blood biopsy predicted recurrences more than three months before they were found on CT scans.

The test could also be used to provide early diagnosis of cancer, but researchers say there are many factors that have to be addressed before the blood biopsy could be used as a foolproof indicator of cancer.

Doctors face countless questions if the blood test shows cancer DNA, such as where is the tumor? What kind of cancer is the patient dealing with? And does finding the tumor early equal a better outcome? Some cancers disappear on their own, stop growing or are just as treatable if found later rather than earlier.