A blood test for tumor DNA tracked melanoma fairly well, but it missed tumors in the brain
Original title: Integrated longitudinal analysis of ctDNA, radiologic response, and tumor volume reveals spatial and temporal heterogeneity in advanced melanoma.
How far along is this research?
- Lab cells
- Animals
- Review
- Tested in people
This was tested in people. That is the most reliable kind of research we share.
This looked back at records from people, but the blood test is not yet proven for everyday care.
The short version
A blood test that looks for bits of tumor DNA went up as melanoma got worse, but it often missed tumors in the brain, lung, and liver.
What was studied. Researchers looked back at records from 42 people with advanced melanoma treated with immune therapy drugs. They compared a blood test for tumor DNA with scans taken over time, using 241 blood samples in total.
What they found. Tumor DNA in the blood tended to be higher when the cancer was growing and when there was more tumor in the body. The test matched the scans best when the blood draw and the scan were close in time. It worked better for tumors in the lymph nodes and belly lining, and it often did not pick up tumors in the lung, liver, or brain.
What this means, and what it doesn't
What it could mean: Someday, a blood test like this might help doctors check on melanoma between scans. For people whose melanoma has spread to the brain, this test may not show what is going on there, so scans still matter.
What it doesn't mean: This does not mean a blood test can replace brain scans. It was a look back at past records from a small group, not a test of a new treatment. The blood test was only fair at spotting when cancer was growing. This is not a cure and does not change care today.
Source: PubMed, September 17, 2026 · Read the original
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