Results from NHS-Galleri multi-cancer detection test trial

1 June 2026

More than 142,000 volunteers aged 50-77 took part in the trial. Participants were recruited in just over 10 months, using innovative methods by colleagues in the CPTU, and other partners, including:

• Addressing healthy volunteer bias using a data-driven recruitment algorithm that enabled greater recruitment from older and more deprived backgrounds
• Using NHS DigiTrials to access to patient data (the first trial to do so since Covid)
• Utilising a call centre supported by interpreter services so that people from all communities could be involved, regardless of their spoken language, to ensure that a diverse population could participate in the trial
• taking the trial to people, using a mobile clinic model local communities, both urban and rural

The trial also introduced an innovative approach to delivering results to participants who had a positive blood test, with the CPTU developing a centralised nursing and participant navigator system to support communication and care. Where needed, participants were referred via a bespoke pathway into urgent suspected cancer pathways across more than 50 NHS trusts in England.

The NHS-Galleri trial was specifically testing whether adding a blood test to NHS screening could reduce the combined number of cancers diagnosed at a later stage (stage 3 or 4) over three years. While this primary endpoint was not met, comparing those who had the test with those who did not, there was no difference in the number of people diagnosed with late-stage cancer overall - the trial did show that substantially fewer of the most advanced cancers (stage IV) were diagnosed in people who had an annual MCED blood test.

As well as also showing that the blood test was accurate and safe in screening for cancer, the trial showed a trend towards fewer late-stage cancers being diagnosed the second- and third-time people had the blood test, with a >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 - a remarkable level of accuracy considering that only 6% of people investigated for urgent suspected cancer by the NHS have cancer diagnosed.

Perhaps most encouragingly, results presented at the ASCO 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.

Speaking on the results, CPTU lead Peter Sasieni, co-investigator and lead statistician for the NHS-Galleri trial, 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.”

He added: "I am incredibly proud of the role that the Cancer Prevention Trials Unit,  (supported by Cancer Research UK) played in delivering this trial, one of the fastest recruiting trials in the last 50 years, to the highest ethical standards. I’m proud of the novel ways in which the team encouraged and supported inclusive participation from communities that are too often under represented in clinical trials. By being ambitious and collegiate, we can be more confident that any results from this trial are relevant to everyone.” 

The researchers will continue to analyse the data from the trial, with further results to be reported. Sub-studies are examining the acceptability of this type of screening and the psychological impact of a positive test result, and with further follow-up the team will study the impact of annual screening with a multicancer test on cancer mortality rates. The NHS and other health organisations will review the results of the trial in detail to understand how this type of test could be used for cancer screening in the future.