The NHS multi-cancer blood test trial missed its main goal. New data show how the test performed
A blood test that looks for many cancers at once did not reduce late-stage diagnoses in a randomized trial of 142,250 people. Newly published data show that about half of its positive results were cancer, but it missed most cancers overall.
The NHS-Galleri trial randomized 142,250 people aged 50 to 77 in England to a multi-cancer early detection (MCED) blood test added to usual care, or to usual care alone. The trial’s primary goal, a reduction in stage III and IV cancer diagnoses in the test group, was not met.
On September 22, 2026, the investigators published the test’s performance across three annual screening rounds in Nature Medicine. These were prespecified secondary analyses, reported descriptively.
What the test did
Across the three rounds, 937 people had cancers detected by the test. Between 46% and 58% of positive results were confirmed as cancer, depending on the round, and specificity was high, at 99.5% to 99.6%. But the test found only 26.7% to 37.2% of all cancers diagnosed in the people tested, so most cancers were missed.
In the earlier PATHFINDER study in the US, 38% of positive results were cancer, and people whose result was a false alarm waited a median of 162 days for an all-clear.
What it means for you
A negative result from a multi-cancer blood test does not rule out cancer, and the largest randomized trial so far did not show fewer late-stage diagnoses. Recommended screenings such as colonoscopy, mammography and cervical screening have trial evidence; our cancer screening guide lists them by age.