A blood test designed to detect multiple cancers before symptoms appear has been shown to be feasible at scale within the NHS, according to experts. The Galleri test works by identifying DNA shed by cancer cells in the bloodstream, offering early indications of the disease.
Results from a trial involving 142,942 people in the UK aged 50 to 77 with no cancer symptoms were presented at the American Society of Clinical Oncology (Asco) annual meeting in Chicago. The NHS-Galleri trial failed to meet its primary objective of significantly reducing later-stage cancer diagnoses overall.
Despite this setback, experts said the findings offer genuine hope for deadly cancers that currently lack screening options, including ovarian and pancreatic cancers. The test, when used alongside NHS screening programmes, reduced diagnoses of the most advanced cancers by more than a fifth in the second and third years of screening.
There was a 9 per cent reduction in the first screening round, with falls of 22 per cent and 26 per cent in the second and third rounds respectively, in analysis focused on 12 pre-specified cancer types. These 12 cancer types are responsible for two-thirds of cancer deaths in England, and many do not have screening programmes and are usually found late.
Overall, the trial found there were 14 per cent fewer cancers diagnosed at stage 4, and 19 per cent more found at stages 1, 2 and 3. The test also improved how cancers were detected, with four times more people diagnosed as a result of screening and 25 per cent fewer patients diagnosed in emergency settings.
Professor Charles Swanton, lead study author, said: 'This is the first randomised controlled trial of a multi-cancer early detection test to report results, and it represents a landmark achievement for participants and the UK’s National Health Service.' However, some experts urged caution, noting that the primary endpoint was not met and longer-term follow-up is needed.
