{"entity":{"id":"idea-prev-mced-stage-endpoint-surrogate","kind":"idea","name":"Let MCED trials read out on late-stage incidence, with mortality follow-up mandated","aka":[],"tldr":"Multi-cancer early detection blood tests take a decade to prove they save lives. Regulators could accept a fall in late-stage cancers as the first answer, validated against pooled data from completed screening trials, provided approval is conditional on continued mortality follow-up.","summary":"NHS-Galleri chose stage III/IV incidence as its primary endpoint; regulators have not said whether that suffices for approval or coverage. Propose a formal surrogate-validation exercise pooling individual data from completed screening RCTs (NLST, NELSON, UKCTOCS, ERSPC, Minnesota, NordICC) to estimate the trial-level correlation between late-stage incidence reduction and cancer-specific mortality reduction, and a conditional-approval pathway with mandated mortality follow-up.","asOf":"2026-09-08","links":[{"label":"NHS-Galleri trial","url":"https://www.nhs-galleri.org"},{"label":"CISNET","url":"https://cisnet.cancer.gov"}],"tags":[],"related":[],"cancers":[],"sections":["early-detection"],"technologies":["mced","liquid-biopsy"],"targets":[],"drugs":["galleri"],"companies":[],"institutions":[],"pathways":[],"terms":["stage-shift","os"],"trials":["nhs-galleri","pathfinder-2"],"people":[],"bottlenecks":["b-early-detection","b-trial-design"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Across historical screening RCTs, the trial-level relative reduction in stage III/IV incidence predicts cancer-specific mortality reduction well enough (R-squared above 0.7) that a pre-specified late-stage incidence threshold can serve as a conditional endpoint.","rationale":"UKCTOCS is the cautionary case: it shifted stage without reducing mortality because the ovarian cancers that shifted were still lethal. A pooled analysis would quantify when stage shift does and does not translate, per cancer, instead of arguing by anecdote.","test":"Individual-patient-data meta-analysis of screening RCTs (two years, small budget); then FDA/MHRA guidance on conditional MCED approval; NHS-Galleri and the NCI Vanguard study as first users.","maturity":"speculative","actor":"regulator","cost":"small","horizonYears":3},"route":"/ideas/idea-prev-mced-stage-endpoint-surrogate/","neighbours":{"section":[{"id":"early-detection","kind":"section","name":"Early Detection & Screening","route":"/fronts/early-detection/"}],"technology":[{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"},{"id":"mced","kind":"technology","name":"Multi-cancer early detection (MCED)","route":"/technologies/mced/"}],"drug":[{"id":"galleri","kind":"drug","name":"Galleri","route":"/drugs/galleri/"}],"term":[{"id":"os","kind":"term","name":"Overall survival (OS)","route":"/terms/os/"},{"id":"stage-shift","kind":"term","name":"Stage shift","route":"/terms/stage-shift/"}],"trial":[{"id":"nhs-galleri","kind":"trial","name":"NHS-Galleri","route":"/trials/nhs-galleri/"},{"id":"pathfinder-2","kind":"trial","name":"PATHFINDER 2","route":"/trials/pathfinder-2/"}],"bottleneck":[{"id":"b-early-detection","kind":"bottleneck","name":"The hardest cancers are found late","route":"/bottlenecks/b-early-detection/"},{"id":"b-trial-design","kind":"bottleneck","name":"Trial design, endpoints and cost","route":"/bottlenecks/b-trial-design/"}],"paper":[{"id":"paper-nhs-galleri-design-cancers-2022","kind":"paper","name":"NHS-Galleri: design of the largest randomised trial of a multi-cancer blood test","route":"/key-papers/paper-nhs-galleri-design-cancers-2022/"},{"id":"paper-prasad-surrogate-endpoints-jama-im-2015","kind":"paper","name":"Prasad: most surrogate endpoints in cancer trials correlate poorly with survival","route":"/key-papers/paper-prasad-surrogate-endpoints-jama-im-2015/"}]}}