The bold promise of multi-cancer blood tests hits real-world limits
Multi-cancer early detection (MCED) blood tests, including Galleri, promise to detect dozens of cancers from one blood sample, but few have robust randomized trial data; the NHS-backed Galleri trial failed to show improved outcomes in reducing late-stage cancers, and while tests boast high specificity, sensitivity varies and the risk of false positives can lead to anxiety and unnecessary follow-ups, leaving regulators and clinicians cautious until stronger evidence accumulates.
