CCGA: the Circulating Cell-free Genome Atlas behind the Galleri methylation test

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.