A large-scale trial of a multi-cancer blood test involving 142,000 NHS patients has failed to meet its primary objective, according to researchers. The study, which aimed to detect multiple cancer types through a simple blood draw, did not significantly reduce the number of late-stage cancer diagnoses.
Trial Details
The trial, conducted across various NHS sites in England, assessed the Galleri test developed by Grail. This test looks for DNA fragments shed by tumours into the bloodstream, potentially allowing earlier detection of over 50 cancer types. Participants were randomly assigned to receive either the blood test alongside standard screening or standard screening alone.
Results
After a follow-up period, researchers found that the proportion of cancers detected at stage 3 or 4 was similar between the two groups. The test did not achieve a statistically significant reduction in late-stage diagnoses, which was the primary endpoint. However, secondary analyses suggested that the test might detect some cancers earlier, but not enough to change overall outcomes.
Experts emphasize that while the trial did not meet its main goal, it provides valuable data on the real-world performance of multi-cancer early detection tests. The findings underscore the challenges of implementing such tests in a population-wide screening program.
Implications
The results have sparked debate among oncologists and public health officials. Some argue that the test may still have value when combined with other screening methods, while others caution against overhyping its benefits. The NHS will review the evidence before making any decisions about potential rollout.
The trial's failure to meet its primary endpoint highlights the complexity of cancer screening and the need for further research to refine these technologies. Future studies may focus on specific high-risk populations or combine the blood test with other diagnostic tools.
