The Galleri multi-cancer early detection (MCED) trial co-ordinated by the Cancer Prevention Trials Unit (CPTU) at Queen Mary University of London found substantially fewer of the most advanced cancers (stage 4) were diagnosed in people who had an annual blood test.

Professor Peter Sasieni, who leads Queen Mary's CPTU and was co-investigator and lead statistician for the NHS-Galleri trial and analysing its results, said: ‘The results from the NHS-Galleri trial show that using a multi-cancer early detection blood test to supplement existing NHS screening can not only help diagnose some cancers earlier, but also help prevent diagnosis at a later stage, when treatment options are limited and can be less effective.'

As well as also showing that the blood test was accurate at screening for cancer and was safe, the trial showed a trend towards fewer late-stage cancers being diagnosed the second- and third-time people had the blood test, with a greater than 20% reduction in stage 4 cancers diagnosed in the second and third screening rounds.

Just over half of participants with a positive Galleri MCED blood test result had cancer diagnosed.

Results presented at the American Society for Clinical Oncology conference showed a 25% reduction in the number of cancers detected in an emergency situation, such as in A&E, among people who had the test.