Some answers, more questions for multi-cancer early detection tests

Two large studies of multi-cancer early detection (MCED) blood tests — PATHFINDER 2 and NHS-Galleri — deliver complementary data on diagnostic performance, safety and feasibility of implementation, but neither yet demonstrates that screening reduces cancer mortality at the population level. The commentary stresses that acceptable specificity and a manageable burden of follow-up diagnostics are necessary but not sufficient conditions for adopting MCED into routine screening programmes. The decisive question remains whether earlier detection translates into fewer late-stage diagnoses and fewer deaths, which will require longer follow-up and mortality endpoints.