New 'simplified' blood tests could detect early signs of cancer in bid to aid GPs and cut waiting list backlogs
2 June 2023, 15:02 | Updated: 2 June 2023, 15:08
A new blood test to detect cancer could be offered by GPs to speed up diagnoses and reduce NHS backlogs, new data suggests.
An NHS trial of the Galleri blood test has successfully detected two out of of every three cancers in a study of 5,461 people who attended their GP with suspected cancer symptoms.
In cases where the cancer was successfully detected by the blood test, it could also pinpoint where the primary cancer was in 85% of cases.
While the blood test does not detect all cancers, and does not replace screenings for types such as cervical, breast and bowel cancers, it can be used for lung, gynaecological, upper gastrointestinal (GI) or lower GI cancers.
The test, developed by US company Grail, is scheduled to be shown at a global cancer conference on Saturday.
The Symplify study, led by the University of Oxford, involved people from England and Wales who were referred to hospital by their GP with suspected cancer. It works by looking for tiny fragments of tumour DNA in the bloodstream.
Those who participated were an average age of 62-years-old, two thirds were female, and just under half were current or former smokers.
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It found a cancer signal in 323 people's blood, 244 of which were later officially diagnosed with cancer – meaning it accurately detected cancer in 75% of those tested.
The results, which are to be later published in Lancet Oncology, did however also find that 2.5% of people did not have cancer signals picked up in the test, despite being later diagnosed with it – meaning they were given false negatives.
Experts said the findings show how scientists are a step closer to a cancer test in GP surgeries.
NHS England previously remarked the test could be a “game changer” for early cancer detection in patients, which could help eliminating the health risk earlier on.
The test was shown to be most accurate in older patients and those with more advanced cancers, and particularly in ruling out a cancer diagnosis for those experiencing symptoms that could indicate upper gastrointestinal tumours.
Professor Mark Middleton, a consultant medical oncologist at the University of Oxford who led the trial, said: “We see potential for identifying people going to see their GP who are currently not referred urgently to investigate cancer, who do need testing.”
“It has the potential to diagnose cancers earlier and the potential to help achieve cancer targets by reducing the overall number of tests needed to diagnose cancers,” he added.
He also noted the test was good for narrowing down which regions may be cancerous, in instances where symptoms may be too generalised to figure out what region is causing the potential problems.
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NHS national director for cancer, Professor Peter Johnson, also said: “This study is the first step in testing a new way to identify cancer as quickly as possible, being pioneered by the NHS – earlier detection of cancer is vital and this test could help us to catch more cancers at an earlier stage and help save thousands of lives.
“It also shows once again that the NHS is at the forefront of cutting edge, innovative technology.”
Lawrence Young, professor of molecular oncology at Warwick Medical School, University of Warwick, is also optimistic but emphasised of the tests: “The current overall sensitivity of this test remains an issue particularly for certain types of cancer other than those of the upper gastrointestinal tract.
“The real challenge is to diagnose those cancers that are difficult to detect (e.g. lung, pancreas) and use a positive blood test to instigate other investigations such as imaging. To really trust that a negative result on blood testing means no cancer will require more studies.”
The results of these studies come at a time when the backlog of covid is still being felt by cancer patients today.
Updated NHS data shows almost 6,000 patients had to wait more than two months for cancer treatment following an urgent referral from their GP, when NHS guidelines state 85% of patients should be seen within two months.
Experts have stressed the Galleri test, while promising, needs “refining”, as it is crucial the tests are more successful in detecting early tumours and avoiding false positives before they could be used officially.
