{"entity":{"id":"ccga-study","kind":"term","name":"CCGA: the Circulating Cell-free Genome Atlas behind the Galleri methylation test","aka":["CCGA","CCGA3","Circulating Cell-free Genome Atlas","Galleri validation study"],"tldr":"CCGA is the case-control programme of about 15,000 people that trained and validated the Galleri blood test, which reads methylation patterns on cell-free DNA to say whether a cancer signal is present and where it comes from. Its third sub-study set the figures still quoted: very few false positives, but only about one in six stage I cancers detected.","summary":"The Circulating Cell-free Genome Atlas enrolled participants with and without cancer across more than 50 cancer types and used their plasma to develop a targeted methylation classifier; the third sub-study, in 4,077 participants (2,823 with cancer, 1,254 without), was the clinical validation of the refined test. Specificity was 99.5%; sensitivity across all cancers rose with stage, 16.8% at stage I, 40.4% at stage II, 77.0% at stage III and 90.1% at stage IV, and the predicted cancer signal origin was correct in 88.7% of true positives (Klein 2021). Pancreatic cancer was one of the twelve pre-specified cancers that account for most cancer deaths, and its per-cancer sensitivity in the study is higher than the all-cancer average at each stage, which is why pancreatic cancer features in the case for multi-cancer screening; the stage I figure is the honest limit. The test is sold as Galleri and is on the record's pipeline; the record's open problems note that its sensitivity for stage I disease is low and its positive predictive value in average-risk adults poor. DETECT-A tested the predecessor approach prospectively.","asOf":"2026-09-24","links":[{"label":"Klein et al., Ann Oncol 2021: CCGA3 validation of the Galleri methylation test in 4,077 participants","url":"https://doi.org/10.1016/j.annonc.2021.05.806"}],"tags":["pancreatic-molecular"],"related":[],"cancers":["pancreatic"],"sections":[],"technologies":["mced","cfdna-methylation-testing","methylation-profiling"],"targets":[],"drugs":["galleri"],"companies":[],"institutions":[],"pathways":[],"terms":["ppv","cfdna","stage-shift","detect-a-study"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-klein-ccga3-mced-validation-ann-oncol-2021"],"journals":[],"dependsOn":[],"notes":[],"category":"Trials"},"route":"/terms/ccga-study/","neighbours":{"cancer":[{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"}],"technology":[{"id":"cfdna-methylation-testing","kind":"technology","name":"Cell-free DNA methylation tests","route":"/technologies/cfdna-methylation-testing/"},{"id":"methylation-profiling","kind":"technology","name":"DNA methylation profiling","route":"/technologies/methylation-profiling/"},{"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":"cfdna","kind":"term","name":"Cell-free DNA (cfDNA)","route":"/terms/cfdna/"},{"id":"detect-a-study","kind":"term","name":"DETECT-A: a blood test plus PET-CT to screen 10,006 women with no symptoms","route":"/terms/detect-a-study/"},{"id":"ppv","kind":"term","name":"Positive predictive value (PPV)","route":"/terms/ppv/"},{"id":"stage-shift","kind":"term","name":"Stage shift","route":"/terms/stage-shift/"}],"paper":[{"id":"paper-klein-ccga3-mced-validation-ann-oncol-2021","kind":"paper","name":"Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set","route":"/key-papers/paper-klein-ccga3-mced-validation-ann-oncol-2021/"}]}}