A blood test for more than 50 forms of cancer could help speed up diagnosis and fast-track patients for treatment, a study suggests.
NHS trial results of the liquid biopsy, published at the world’s largest cancer conference in the US, suggest the Galleri blood test has the potential to spot and rule out cancer in people with symptoms.
The test detects tiny fragments of tumour DNA in the bloodstream. It alerts doctors as to whether a cancer signal has been detected, and predicts where in the body that signal may have originated.
Experts welcomed the findings from the trial but said more research would be needed before the test, made by the California company Grail, could be rolled out in healthcare systems.
The Symplify study, led by the University of Oxford, involved 5,461 people in England and Wales who were referred to hospital by their GP with suspected cancer. Its results are being presented at the American Society of Clinical Oncology’s annual meeting in Chicago.
The test correctly revealed two-thirds of cancers among those in the study. In 85% of those positive cases, it was also able to pinpoint the original site of cancer. It was more accurate in older patients and those with more advanced cancers, according to the trial results.
Mark Middleton, a professor of experimental cancer medicine at Oxford, who led the trial, said the test had “potential for identifying people going to see their GP who are currently not referred urgently to investigate cancer … who do need testing”.
It was also likely the test could speed up diagnosis “where it is not certain which rapid diagnostic pathway is the right one”, Middleton said.
“The first use case above has the potential to diagnose cancers earlier; the second and third have the potential to help achieve cancer targets (and therefore reduce waiting for patients) by reducing the overall number of tests needed to diagnose cancers.”
Lawrence Young, a professor of molecular oncology at the University of Warwick, urged caution but added: “This is an important study that shows we are edging towards an era when blood testing for cancer, alongside other tests of symptomatic patients, could really impact early diagnosis and significantly improve clinical outcome.”
Dr Richard Lee, of the Institute of Cancer Research in London, said testing in patients with symptoms potentially indicating cancer could help to enable quicker diagnostic testing in those deemed to be at high risk. “This could result in earlier diagnosis of cancer or faster reassurance for those without cancer,” he added.
Prof Nicholas Turner, also of the Institute of Cancer Research, said the study provided valuable data that enhances the evidence liquid biopsies could be used to more rapidly diagnose cancer in patients presenting with symptoms.
“It could well be useful in the future to fast-track patients into rapid-access clinics, and especially in people where imaging findings are uncertain,” said Turner.
Dr David Crosby, the head of prevention and early detection research at Cancer Research UK, said: “The findings from the study suggest this test could be used to support GPs to make clinical assessments, but much more research is needed in a larger trial to see if it could improve GP assessment, and ultimately patient outcomes.”
The NHS has also been using the Galleri test in thousands of people without symptoms, to see if it can detect hidden cancers. Results are expected later this year. If successful, it plans to roll the test out to about 1 million people.
