OneTest for Cancer

Overview

• Evidence grade insufficient for the claim that taking this test reduces late-stage diagnosis or cancer deaths: no randomised trial of it has reported either outcome, and its published performance comes from case-control or single-arm studies. The only randomised result for any multi-cancer test, NHS-Galleri, did not show fewer stage III or IV cancers.
• Single protein tumour markers such as CEA and CA-125 are not recommended for screening people without symptoms because they rise in many non-cancer conditions; combining them is the test's premise, and its accuracy in screening has not been published.
• What a result means: a positive result is a reason for further tests, not a diagnosis; a negative result does not rule cancer out and does not replace the screening tests that have been shown to work (bowel, breast, cervical and, where eligible, lung screening).