{"entity":{"id":"idea-prev-blood-crc-test-for-non-responders","kind":"idea","name":"Offer the blood test for bowel cancer only to people who refuse stool tests or colonoscopy","aka":[],"tldr":"Blood tests for bowel cancer miss most precancerous polyps, so they should not replace stool tests. But for the third of people who never do any screening, a blood test may beat nothing.","summary":"Shield (Guardant) is FDA-approved with about 83% sensitivity for colorectal cancer but around 13% for advanced adenomas; the concern is substitution away from FIT and colonoscopy. Propose a randomised trial in persistent non-responders: blood test offer versus repeat FIT offer, endpoint stage I-II cancers detected per 1,000 invited.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (The hardest cancers are found late): Crosby et al., Early detection of cancer (Science 2022)","url":"https://doi.org/10.1126/science.aay9040"}],"tags":[],"related":[],"cancers":["colorectal"],"sections":["early-detection"],"technologies":["liquid-biopsy"],"targets":[],"drugs":["shield"],"companies":["guardant-health","freenome"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-early-detection","b-prevention-adoption"],"keyPapers":["paper-crosby-science"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Offering a blood test to non-responders raises participation by at least 20 percentage points and yields more early-stage cancers per 1,000 invited than a further FIT invitation.","rationale":"Uptake, not test accuracy, drives population benefit; a moderately sensitive test with high uptake beats an excellent test nobody takes.","test":"Run a 20,000-person RCT in a programme with good registry linkage.","maturity":"early-clinical","actor":"payer","cost":"medium","horizonYears":3},"route":"/ideas/idea-prev-blood-crc-test-for-non-responders/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"early-onset-colorectal","kind":"cancer","name":"Early-onset colorectal cancer (under 50)","route":"/cancers/early-onset-colorectal/"}],"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/"}],"drug":[{"id":"shield","kind":"drug","name":"Shield","route":"/drugs/shield/"}],"company":[{"id":"freenome","kind":"company","name":"Freenome","route":"/companies/freenome/"},{"id":"guardant-health","kind":"company","name":"Guardant Health","route":"/companies/guardant-health/"}],"bottleneck":[{"id":"b-prevention-adoption","kind":"bottleneck","name":"Prevention we already have is not deployed","route":"/bottlenecks/b-prevention-adoption/"},{"id":"b-early-detection","kind":"bottleneck","name":"The hardest cancers are found late","route":"/bottlenecks/b-early-detection/"}],"paper":[{"id":"paper-crosby-science","kind":"paper","name":"Early detection of cancer","route":"/key-papers/paper-crosby-science/"}]}}