The first prospective study to evaluate the accuracy of a blood test for people being screened for colorectal cancer (CRC) revealed a high sensitivity and specificity.
At 90% specificity, the blood assay (Guardant Health) was 100% sensitive for detecting CRC. At 95% specificity, sensitivity was 88%.
The blood assay detects circulating tumor DNA from cancer in the bloodstream, which is then analyzed for multiple factors, including cancer genetics and methylation.