New blood test predicts if breast cancer treatment will work
Researchers in London have developed a simple blood test that can tell early on if advanced breast cancer treatments are likely to help.
By measuring tumor DNA in the blood before and after four weeks of therapy, researchers found changes in circulating tumor DNA were associated with later treatment response and could provide an early indication of who is likely to benefit or not, although trials are under way to test whether adapting treatment based on these early tests improves outcomes.
How the test works
The study tracked 167 patients with advanced breast cancer, split into two groups based on their cancer type and treatment.
Patients with low tumor DNA levels before treatment, especially those with triple-negative breast cancer, had much better outcomes—living about 10 months without their cancer getting worse versus just over 4 months for those with higher levels.
Why this matters
If tumor DNA becomes undetectable after four weeks of treatment, patients tend to do far better—sometimes tripling their time before the disease progresses.
As Dr. Iseult Browne puts it, this test could help doctors quickly switch up treatments that aren't working instead of waiting months to see results.
Professor Nicholas Turner adds it could even help personalize care for people with earlier-stage cancers down the line.