A simple blood test that can detect more than 50 types of cancer before symptoms appear is being trialled by Britain’s National Health Service.
It can also pinpoint the location of the disease in the body.
The Galleri test works by seeking out chemical changes in fragments of genetic code – cell-free DNA (cfDNA) – that leak from tumours into the bloodstream.
NHS England will today launch the world’s largest trial, with the aim of attracting 140,000 volunteers at mobile testing sites across England.
The test, which is available in the US, can detect cancers that are not routinely screened for. It could be a game changer in the battle against the disease, experts say.
Catching cancer early is vital if patients are to receive prompt treatment. The test has the potential to save thousands of lives in the UK every year.
Amanda Pritchard, chief executive of NHS England, told Sky News: “It allows us hopefully to then identify cancers at a much earlier stage when people have a much better chance of making a full recovery and treatment is much easier.”
Some cancer tumours are known to shed DNA into the blood a long time before a person starts having symptoms.
The Galleri test does not detect all cancers and does not replace NHS screening programmes, such as those for breast, cervical and bowel cancer.
In the US, it has been recommended for people at higher risk of cancer, including those aged over 50.
Dame Cally Palmer, National Cancer Director of NHS England, told BBC Radio 4’s Today programme that the test “could be transformative in our ability to detect and diagnose cancer early”.
She said it is “so important particularly in some cancers which are really hard to detect early”.
Dame Cally added: “This is just a simple blood test and this is for people who have no symptoms of cancer at all and haven’t had any diagnosis within the last three years.”
She also said many volunteers invited to take part in the trial may discover they have hard-to-detect cancers which include pancreatic, neck, lung and throat cancers.
The NHS aims to recruit 140,000 volunteers in eight areas of England to see how well the test works in the health service.
Letters are being sent to people from different backgrounds and ethnicities aged between 50 and 77 asking them to take part.
From Monday, selected volunteers can turn up at several mobile testing clinics in retail parks and other community locations across the country.
After giving a blood sample, each person will be invited back after 12 months, and again the following year, to give further samples.
In a statement, Ms Pritchard said: “This quick and simple blood test could mark the beginning of a revolution in cancer detection and treatment here and around the world."
She said the NHS has a "successful track record of leading the way on innovations in cancer diagnosis and treatment, from CAR-T therapy to Covid-friendly drugs".
Ms Pritchard said that if given the green light for use in the UK, the Galleri test "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".
The NHS trial is being led by the Cancer Research UK and King’s College London Cancer Prevention Trials Unit, together with Grail, which developed the Galleri test.
Eight NHS Cancer Alliances are supporting the plan, with people invited to take part from Cheshire and Merseyside, Greater Manchester, the North East, West Midlands, East Midlands, East of England, Kent and Medway, and South East London.
The first results from the study are expected by 2023. If successful, the NHS in England plans to extend the introduction to another one million people in 2024 and 2025.
In the trial, half of the people will have their blood sample screened with the Galleri test straight away and the other half will have their sample stored for possible future testing.
This will allow scientists to compare the stage at which cancer is detected between the two groups.
Anyone in the test group who is found to potentially have cancer will be contacted by the trial nurse and referred to an NHS hospital for further tests.
“We need to study the Galleri test carefully to find out whether it can significantly reduce the number of cancers diagnosed at a late stage," said Prof Peter Sasieni, director of the Cancer Research UK and King’s College trials unit, and one of the trial’s lead investigators.
“The test could be a game-changer for early cancer detection and we are excited to be leading this important research.
“Cancer screening can find cancers earlier when they are more likely to be treated successfully, but not all types of screening work.”
Sir Harpal Kumar, president of Grail Europe, said: “We’re delighted to partner with the NHS to support the NHS long-term plan for earlier cancer diagnosis, and we are eager to bring our technology to people in the UK as quickly as we can.
“The Galleri test cannot only detect a wide range of cancer types but can also predict where the cancer is in the body with a high degree of accuracy.
“The test is particularly strong at detecting deadly cancers and has a very low rate of false positives.”
Health Secretary Sajid Javid said: “The UK’s world leading scientists continue to pioneer innovative cancer diagnosis and treatments, so our brilliant NHS staff have the tools to spot the disease as early as possible and give people the care they need.
“Early diagnosis can save lives and this revolutionary new test can detect cancers before symptoms even appear, giving people the best possible chance of beating the disease.
“Ensuring fewer people need treatment for advanced cancer is vital for patient care and another example of the NHS innovating to be more efficient, which will be crucial in bringing down the backlog.”
Research published in June in the journal Annals of Oncology found that the test had a very low false positive rate, meaning very few people would have cancer wrongly diagnosed.
Scientists analysed how the test worked in 2,823 people with the disease and 1,254 people without.
It correctly identified cancer in 51.5 per cent of cases, across all stages of the disease, and wrongly detected cancer in only 0.5 per cent of cases.
When it came to solid tumours that are not screened for – such as oesophageal, liver and pancreatic cancers – the ability to generate a positive test result was twice as high (65.6 per cent) as for solid tumours with screening options such as breast, bowel, cervical and prostate cancers.
When it came to blood cancers, about 55 per cent of cases were detected, while the test correctly identified the tissue in which the cancer was located in the body in 88.7 per cent of cases.
Experts have stressed that anyone with symptoms of cancer should always seek help from their GP.