The first full results from the NHS-Galleri trial - a research study looking into the use of a blood test to see if it can help the NHS to detect cancer early - were presented at the annual American Society for Clinical Oncology (ASCO) conference on 30 May.
The NHS-Galleri trial was launched in 2021 and originally led by King's College London Cancer Prevention Trials Unit. It was co-led by former King's academic Professor Peter Sasieni. In 2023 Professor Sasieni and the coordination of the trial moved to Queen Mary University of London.
The trial aims to see if using the Galleri multi-cancer early detection (MCED) test alongside existing cancer screening can help to find cancer at the time of screening and before symptoms start, when there are usually more treatment options and better outcomes.
The Galleri blood test aims to detect a potential cancer 'signal' of DNA fragments from a blood sample, and then predict the potential site of that cancer. More than 142,000 volunteers aged 50-77 from eight regions of England took part in the trial - the world's first and largest randomised trial of this new technology. Participants provided three blood samples over two years at mobile clinics stationed in more than 150 locations across England.
The trial found that substantially fewer of the most advanced cancers were diagnosed in people screened yearly with the Galleri blood test. There was no difference in the number of people diagnosed with late-stage cancer overall (stage 3 and stage 4 cancers together), the main goal of the trial, between people who had the test and those who did not. However, fewer late-stage cancers were seen the second and third time people had the test, including for difficult-to-diagnose cancers such as oesophageal-gastric, pancreatic and ovarian cancers.
Dr Thomas Round, NIHR Clinical Lecturer in General Practice at King's College London, helped to deliver the trial as a co-lead clinical supervisor. His role included the delivery of results to patients who had positive screening tests and referral into the NHS with the trial nursing team.
As a GP, I see the importance of timely diagnosis of cancer, with earlier detection improving patient outcomes. This is potentially game-changing technology, aiming to pick up signals of cancer before you have symptoms. This is particularly important for difficult-to-diagnose cancers like pancreatic and ovarian cancer, which have very vague symptoms and are often diagnosed at a late stage.
Dr Thomas Round, NIHR Clinical Lecturer in General Practice at King's
"King's and Guy's and St Thomas' NHS Foundation Trust had a pivotal role in trial set up and delivery at scale for this world's first and largest trial of these novel tests. I would like to thank all the staff who helped deliver this trial and the 142,000 people who took part," said Dr Round.
Dr Saoirse Dolly was oncology lead consultant for trial delivery at Guy's and St Thomas' NHS Foundation Trust, one of the recruiting sites for the study. She said: "It has been a privilege to be involved in the NHS-Galleri trial. The speed and scale of recruitment have been remarkable and demonstrate what the NHS can achieve when researchers, clinicians and patients come together behind a shared goal."
The trial represents an exciting step forward in the development of innovative cancer detection technologies. While there is still much to learn, studies like this are helping to pave the way towards a future where more cancers are found earlier, more patients can benefit from curative treatment, and survival outcomes continue to improve. Most importantly, this research offers real hope for our patients and their families.
Dr Saoirse Dolly
The trial results showed that the blood test was accurate at screening for cancer and was safe. Results also showed that fewer cancers were detected in an emergency situation, such as in A&E, among people who had the test. Using the test meant that more cancers were found by screening than by other ways.
The researchers will continue to analyse the data from the trial over the coming months and years. 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 in the future.
