Writing in STAT, Dr. H. Gilbert Welch, a physician and cancer screening researcher at Brigham and Women's Hospital, argues that the FDA should not approve Grail's multicancer early detection blood test. He notes that a randomized trial of 140,000 people failed to show a reduction in late-stage cancer diagnoses, the trial's surrogate endpoint, and that an FDA advisory panel nevertheless recommended approval.
Welch acknowledges that the underlying technology is remarkable, as it can detect small amounts of tumor DNA in the blood. But he contends that this does not make it a valid screening test. He points out that screening can find more cancers and improve survival statistics without reducing cancer deaths, citing ovarian cancer screening as an example where late-stage diagnoses fell but mortality did not.
Welch also warns that FDA approval would trigger a 'tsunami' of public and private spending. A law passed earlier this year, the Medicare Multi-Cancer Early Detection Screening Coverage Act, mandates Medicare coverage of multicancer screening tests after FDA approval, bypassing the usual U.S. Preventive Services Task Force process. He criticizes the lobbying effort behind the law and the claim that multicancer screening could reduce health disparities, calling that idea 'seriously' misguided.