LONDON, March 7 (UPI) -- A blood test can detect changes in tumor DNA, potentially helping doctors detect melanoma relapse far earlier, according to a study in England.
Scientists at Cancer Research UK found the blood test detects mutations in circulating tumor DNA indicating potential drug resistance or relapse, which would allow treatment to start earlier and increase the chance for a patient's survival.
Although the study was small, and scientists say the test's accuracy needs to be tested in a much larger trial before it is used in clinics, any possibility of improving how cancer is tracked will improve treatment.
"One of the sinister things about melanoma is that it can lay dormant for years and then suddenly re-emerge, probably as it escapes from the control of the body's immune system," Dr. Peter Johnson, chief clinician at Cancer Research UK, said in a press release. "Being able to track cancers in real time as they evolve following treatment has huge potential for the way we monitor cancers and intervene to stop them growing back."
For the study, published in the journal Cancer Discovery, the scientists analyzed 364 samples from 214 patients using whole exome sequencing and targeted sequencing of circulating tumor DNA.
The scientists were able to use the test to observe treatment responses, as well as identify where tumors may be resisting the therapy. Within circulating tumor DNA, the researchers found mutations to genes such as NRA and PI3K, which the scientists said can allow tumors to resist treatments.
"Being able to spot the first signs of relapse, so we can rapidly decide the best treatment strategy, is an important area for research," Dr. Richard Marais, a professor at the University of Manchester, said. "Our work has identified a way for us to do this but we still need to test the approach in further clinical trials before it reaches patients in the clinic."