The blood test that will diagnose more than 50 types of cancer is on its way to approval

A single blood test that promises to detect more than 50 types of cancer is reaching its moment of truth. The FDA staff did not raise significant concerns about its performance and safety, but a large trial in the UK did not achieve its primary endpoint. Now an expert panel will discuss whether the evidence is sufficient to recommend its approval.

The Galleri blood test, which promises to detect more than 50 types of cancer through a blood sample and analysis of DNA methylation patterns, faces a significant regulatory crossroads. An external expert panel of the FDA is expected to discuss the company's application for early marketing approval. The FDA staff did not raise significant concerns about the test's analytical performance, study design, or primary safety analysis. However, a large UK trial, which included about 142,000 participants aged 50 to 77 without symptoms, missed its primary endpoint – a significant reduction in the number of cancers diagnosed at stages 3 and 4 among 12 deadly cancer types. The study observed encouraging trends in secondary measures, but there is still no proof that the test reduces cancer mortality. The test is not intended to replace existing screening tests such as mammography or colonoscopy, but to serve as an addition. Even if a positive recommendation is received, the final decision will be up to the FDA, and the real test will be its ability to prove that early detection indeed translates into saving lives.