Annual screening with a blood test designed to detect multiple cancers before symptoms appear is 'feasible at scale' on the NHS, according to experts. The NHS-Galleri trial is exploring how well the Galleri blood test works within the health service alongside existing screening to pick up cancer cases earlier.
The results are being presented at the American Society of Clinical Oncology (Asco) annual meeting in Chicago, but come after it emerged the test had failed to meet its primary endpoint of showing a statistically significant reduction in later stage cancers. However, the findings 'still offer genuine hope' for deadly cancers that lack screening options, including ovarian and pancreatic, experts said.
The Galleri test works by identifying DNA in the bloodstream that has been shed by cancer cells, giving the earliest signs somebody may have the disease. The NHS-Galleri trial includes 142,942 people in the UK aged 50 to 77 with no cancer symptoms. All had blood taken once a year for three years and half had their sample tested using Galleri.
In February, the test's developer Grail said the trial had not met its primary endpoint, which is to show a statistically significant combined reduction in later stage 3 and 4 cancers. The findings being presented at Asco show that 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% reduction in the first screening round, with falls of 22% and 26% in the second and third round respectively, in analysis focused on 12 pre-specified cancer types.
Overall, the trial found there were 14% fewer cancers diagnosed at stage 4, and 19% more found at stages 1, 2 and 3. The test also improved how cancers were detected, Grail said, with four times more people diagnosed as a result of screening and 25% 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. The trial demonstrates that annual multi-cancer early detection testing is feasible at scale within a national health system and can increase the number of cancers detected through screening, including many for which no organised programme currently exists.'
