Multi-cancer early detection (MCED) tests are blood tests designed to screen for signals of many cancer types at once, rather than testing for one cancer at a time.
Most look for cell-free DNA fragments shed by tumors into the bloodstream, checking methylation patterns that can indicate cancer is present.
They do not diagnose cancer — a positive result means further imaging or biopsy is needed to confirm and locate it.
Galleri made by GRAIL, is the best-known MCED test.
It’s been sold since 2021 but isn’t yet FDA-approved.
In a study of 71,122 participants randomly assigned to the intervention group and 71,128 to a control group:The incident rate of stage three or four cancer did not differ significantly between the groups in incidence rate ratio intervention across control and they did not observe a lower incidence of rate of stage three or four cancer across 12 pre-specified cancers after three screening rounds with multi cancer early detection test testing plus usual care.