NHS to Trial Galleri Cancer Blood Test

Peter Russell

September 13, 2021

The NHS is to recruit tens of thousands of people to take part in a trial of a blood test that aims to detect more than 50 types of cancer before symptoms appear.

The Galleri test works by finding cell-free DNA (cfDNA) that leaks from tumours into the bloodstream. The results can point to where in the body the cancer is coming from.

The NHS-Galleri randomised controlled trial aims to establish whether testing should be rolled out across the NHS.

'Revolution' in Cancer Detection

Amanda Pritchard, NHS England chief executive, said: "This quick and simple blood test could mark the beginning of a revolution in cancer detection and treatment here and around the world."

If successful, the blood test could improve early cancer detection and improve treatment outcomes for patients. "By finding cancer before signs and symptoms even appear, we have the best chance of treating it, and we can give people the best possible chance of survival," she said.

The trial will involve 140,000 volunteers aged between 50 and 77 from different backgrounds and ethnicities.

Participants, who must not have had a cancer diagnosis in the last 3 years, will be asked to give an initial blood sample, then another at 12 months, and again at 2 years.

Half of the participants will have their blood sample screened initially with the Galleri test, and the other half will have their sample stored for possible future testing.

Scientists will then be able to compare the stage at which cancer is detected between the two groups.


Prof Peter Sasieni, director of King's College London's Clinical Trials Unit, and one of the trial’s lead investigators, said the test could prove to be "a game-changer for early cancer detection" if it proved to "significantly reduce the number of cancers diagnosed at a late stage".

A recent study published in the Annals of Oncology found that a multi-cancer early detection (MCED) test demonstrated overall sensitivity for cancer signal detection of 51.5%, increasing from 16.8% for stage I cancers to 40.4% for stage II, 77.0% for stage III, and 90.1% for stage IV.

Stage I-III sensitivity was 67.6% for 12 pre-specified cancers that account for around two-thirds of cancer deaths in the USA.

Specificity for cancer signal detection was 99.5%, so there were few false positive results (0.5%).

NHS Cancer Strategy

Ms Pritchard said: "The Galleri blood test, if successful, could play a major part in achieving our NHS Long Term Plan ambition to catch three quarters of cancers at an early stage, when they are easier to treat."

Initial results of the study, taking place in eight English regions, are expected by 2023.

The first people to take part will have blood samples taken at mobile testing clinics in retail parks and other convenient community locations.

If successful, the NHS in England says testing could be rolled out to a further million people in 2024 and 2025.

Dame Cally Palmer, NHS England national director for cancer, said: "It is an absolute priority to speed up the earlier detection of cancer to improve survival, and this trial has the potential to do just that across a range of types of cancer.

"We are very grateful to all the people who will be taking part in this important initiative, which could help us save many more lives in the future."

The NHS-Galleri trial is led by The Cancer Research UK and King’s College London Cancer Prevention Trials Unit in partnership with the NHS, and healthcare company, GRAIL, which developed the Galleri test.

Sir Harpal Kumar, president of GRAIL Europe, said: "The test is particularly strong at detecting deadly cancers and has a very low rate of false positives."


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