NHS-Galleri Blood Test Trial Finds No Significant Reduction in Late-Stage Cancer Diagnoses

The New England Journal of Medicine has published the full results of the NHS-Galleri trial, a study testing whether adding a blood-based multicancer early-detection test to routine care could reduce the proportion of cancers diagnosed at stage III or IV — the later, harder-to-treat stages. After three rounds of screening, the incidence of late-stage cancer did not differ much between participants who received the test alongside usual care and those who received usual care alone.

The Galleri test works by detecting chemical signals shed by tumour cells into the bloodstream, with the aim of identifying cancers before symptoms appear. The trial was a collaboration between NHS England and the test’s developer, and involved tens of thousands of participants across England.

The results do not mean the test has no value — the trial was measuring a specific outcome, late-stage incidence, and researchers will continue to analyse the data. But the headline finding is clear: on this measure, adding Galleri to usual care did not produce a statistically significant difference.

Early detection is one of the NHS’s stated priorities for improving cancer survival rates. Tests like Galleri have attracted attention because a single blood draw can screen for signals associated with dozens of cancer types simultaneously, unlike existing screening programmes which target one cancer at a time.

Anyone concerned about cancer symptoms should contact their GP or call NHS 111. In an emergency, dial 999.

Key information

• The full trial results are published in the New England Journal of Medicine
• NHS 111 is available 24 hours a day for health concerns that are not emergencies
• Speak to your GP if you have symptoms that worry you or questions about cancer screening