A blood test for more than 50 types of cancer could help speed up diagnosis, a new study suggests.
Results from a trial in North America show the test was able to identify a wide range of cancers, three-quarters of which are not covered by any form of screening program.
More than half of cancers were detected at an early stage, where they are easier to treat and potentially curable.
The Galleri test, carried out by the American pharmaceutical company Grail, can detect cancerous DNA fragments detached from a tumor and circulating in the blood. It is currently being tested by the NHS.
The trial followed 25,000 adults in the United States and Canada for a year, and nearly one in 100 tested positive. For 62% of these cases, the cancer was later confirmed.
Lead researcher Dr. Nima Nabavizadeh, an associate professor of radiologic medicine at Oregon Health and Science University, said the data showed the test could “fundamentally change” their approach to cancer screening.
He explained that this could help detect many types of cancer “earlier, when the chances of treatment success, or even cure, are greatest.”
The test correctly ruled out cancer in more than 99% of those who tested negative.
When combined with breast, bowel, lung and cervical screening, it increased the number of cancers detected sevenfold.
Above all, three quarters of the cancers detected were those for which no screening program was applied, such as ovarian, liver, stomach, bladder and pancreatic cancer.
The blood test made it possible to correctly identify the origin of the cancer in nine out of ten cases.
These impressive results suggest that blood testing could eventually play a major role in the early diagnosis of cancer.
But scientists not involved in the research say more evidence is needed to demonstrate whether the blood test reduces cancer deaths.
Clare Turnbull, professor of translational cancer genetics at the Institute of Cancer Research in London, said: “Data from randomized studies, with mortality as an endpoint, will be absolutely essential to determine whether apparently earlier detection by Galleri translates into mortality benefits. »
The main results are due to be published on Saturday at the European Society of Medical Oncology congress in Berlin, but full details have not yet been published in a peer-reviewed journal.
Much will depend on the results of a three-year trial involving 140,000 NHS patients in England, which will be published next year.
The NHS has previously said that if the results were conclusive it would expand testing to a further million people.
Sir Harpal Kumar, president of Grail’s biopharmaceuticals division, called the results “very compelling.”
Speaking to BBC Radio 4’s Today programme, he said: “The vast majority of people who die from cancer do so because we detect their cancer too late.”
Many cancers are detected when they are “already very advanced”, he added, explaining that the aim is to “move to earlier detection, when we will have the possibility of using much more effective and potentially curative treatments”.
But Cancer Research UK’s Naser Turabi warned that more research is needed to “avoid overdiagnosing cancers that may not have caused harm”.
“The United Kingdom The National Testing Committee “will play a vital role in reviewing the evidence and determining whether these tests should be adopted by the NHS”, he added.
