FDA Advisory Panel Backs Multi-Cancer Blood Test, but Efficacy Doubts Remain
An FDA advisory panel voted to recommend the Galleri blood test for multi-cancer screening, though opinions were split on its effectiveness. All ten panelists agreed the test is safe, but only six and seven voted in favor of its efficacy and benefit-risk balance, respectively. Researchers caution that while the vote is a step forward, further studies are needed to establish the test's clinical value.
The Galleri test detects cancer-related DNA signals in blood, targeting adults aged 50 and older. In a Nature Medicine study of more than 35,000 participants, the test flagged 287 individuals, with roughly 60 percent later confirmed to have cancer. It accurately identified the cancer's origin site in about 91 percent of cases. However, Grail has acknowledged that a negative result does not definitively exclude cancer.
No multi-cancer early detection test has previously received FDA approval, making this vote a potential milestone. The panel's split votes on efficacy and benefit-risk balance reflect lingering questions about real-world value. Experts emphasize that long-term evidence is needed to determine whether early detection translates into fewer advanced cancers and reduced mortality, rather than simply identifying more cases.
If approved, the Galleri test could reshape cancer screening by enabling early detection across multiple cancer types, particularly those lacking existing screening methods. Patients aged 50 and older might benefit from earlier intervention, potentially improving outcomes. However, false positives could lead to unnecessary procedures and anxiety, especially for low-risk individuals. The test's ultimate societal value depends on whether it reduces cancer deaths over time, which may require careful guidelines on which populations should receive it and how positive results are managed.