A blood test missed one woman's lung cancer coming back in her brain
Original title: Minimal residual disease guides postoperative therapy in a patient with ALK-rearranged adenocarcinoma: a case report.
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 is one patient's story, and the test is not yet proven to guide treatment.
The short version
A blood test found no cancer in one woman, but it later spread to her brain.
What was studied. This report is about one 43-year-old woman with a type of lung cancer linked to a gene change called ALK. Her doctors used a blood test that looks for tiny bits of tumor DNA to help decide when to stop her treatment.
What they found. She took a targeted drug called alectinib, had surgery, and then kept taking the drug for two years. Three blood tests in a row found no sign of cancer, so she stopped the drug. Two months later, a new tumor showed up in her brain, and she had to start the drug again.
What this means, and what it doesn't
What it could mean: This blood test may not always catch cancer that is still in the body. A clean test result may not be enough reason on its own to stop treatment. If you have this kind of test, ask your doctor what it can and cannot tell you.
What it doesn't mean: This is the story of just one patient. It does not show how well the test works for most people. It does not mean the test is useless, and nothing here is a cure. This was lung cancer that spread to the brain, not a tumor that started in the brain. The authors say bigger studies are needed before doctors can rely on this test to guide treatment.
Source: PubMed, August 26, 2026 · Read the original
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