Searching for tumor DNA located cancer's spread better than standard test, researchers say
A new blood test might improve doctors' ability to track the spread of advanced melanoma skin cancer, according to results of a small, preliminary study.
The test monitors blood levels of DNA fragments from dead cancer cells, and is more effective than the current test at tracking the severity and spread of advanced melanoma, the researchers said.
""Our study results show that circulating tumor DNA is a superior blood test for evaluating and tracking progression of metastatic melanoma,"" study senior investigator Dr. David Polsky, from NYU Langone Medical Center in New York City, said in a center news release.
Currently, a test that measures blood levels of an enzyme called lactate dehydrogenase (LDH) is done to guide management of the cancer. LDH levels rise during aggressive tumor growth. However, levels of LDH also rise due to other diseases and biological functions, the study authors pointed out.
The new test assesses levels of circulating tumor DNA (ctDNA) released into the blood when tumor cells die, the researchers said.
The study included 31 patients with inoperable advanced (metastatic) melanoma who had both tests done.
The study found that blood levels of ctDNA were elevated in 80 percent of patients about to undergo treatment for the advanced melanoma. Blood levels of LDH were elevated in just 30 percent of such patients, the study showed.
Also, the ctDNA blood test detected cancer recurrence -- confirmed by X-ray or CT scan -- in 85 percent of patients tested and undergoing treatment. The LDH blood test detected 54 percent of such cases, the researchers said.
Previous studies have suggested that ctDNA blood testing may also help monitor progression of breast and colon cancers, Polsky, a dermatologist, said in the news release.
The new study findings are published in the January issue of the journal Molecular Oncology.
The U.S. National Cancer Institute has more about melanoma.