The FDA has approved Guardant Health's Shield blood test as the first primary screening option for colorectal cancer for adults aged 45 and older at average risk. This test, which detects DNA from cancerous tumors in the bloodstream, showed 83% sensitivity in detecting colorectal cancer and 90% specificity for advanced neoplasia in a study of over 20,000 participants. The approval is expected to increase screening rates by providing a less invasive alternative to colonoscopies and stool-based tests, which many find unpleasant. With FDA approval, Shield is also the first blood test for colorectal cancer screening to meet Medicare coverage requirements, making it more accessible. Shares of Guardant Health surged following the announcement, reflecting the market's positive reception. Experts emphasize that a positive result from the Shield test would still require a follow-up colonoscopy to confirm the presence and stage of cancer.