Blood test for 50 cancers fails key goal in NHS trial
BBC World
February 21, 2026
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A groundbreaking blood test designed to detect up to 50 types of cancer failed to meet its primary goal in a major NHS trial. The Galleri test, developed by U.S.-based Grail, aimed to reduce the number of late-stage cancers (stages three and four) by identifying them earlier when they are more treatable. However, while the trial showed a trend toward reducing these advanced-stage cancers, it did not achieve its main objective, leading some experts to question its effectiveness.
Despite missing its primary endpoint, the trial revealed encouraging signs. Specifically, stage-four cancers—a highly deadly form—fell by around 20% in the study. This suggests that while the test may not have succeeded in all aspects of early detection, it could still play a significant role in identifying aggressive cancers at earlier stages. Grail emphasized this positive outcome, noting that further analysis of the data could provide more insights into its potential benefits.
The trial involved 142,000 NHS patients and was initially heralded as a revolutionary step in cancer screening. The test works by detecting fragments of DNA from tumors circulating in the bloodstream, allowing for early detection before symptoms appear. While the full results are yet to be published, experts remain divided on the implications. Some, like Professor Charles Swanton of the NHS, view the reduction in stage-four cancers as a promising sign, especially since these are often incurable if left untreated.
However, other researchers caution against overinterpreting the results. Professor Richard Houlston of the Institute of
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Originally published on BBC World on 2/21/2026