The U.S. Food and Drug Administration (FDA) has recently approved a new blood test for colorectal cancer (CRC) screening, making it easier for individuals to detect the second leading cause of cancer deaths. The blood test, called Shield and manufactured by Guardant Health in California, is the first primary screening option for CRC that meets Medicare coverage requirements.
Results from a large clinical trial involving 20,000 average-risk adults showed that Shield has an 83% sensitivity for detecting CRC. This approval marks a significant advancement in CRC screening, as Shield is the only blood test currently available for this purpose.
Compared to traditional screening methods such as colonoscopy, CT colonography, and stool tests, Shield offers a simpler and less time-consuming alternative. The convenience of the blood test allows for screening during routine doctor's appointments without the need for extensive preparation or time off work.
While Shield has shown reasonable sensitivity and specificity compared to other blood and stool tests, it does not provide the same level of benefit in preventing CRC by detecting and removing precursor lesions (polyps). However, the test's ease of use may encourage more individuals who have been hesitant to undergo screening to get tested.
It is important to note that the Shield test is intended for individuals aged 45 and older with an average risk for colon cancer. Patients considering the test should consult with their healthcare provider to understand its benefits and limitations, as well as to determine insurance coverage.
Early detection of colon cancer is crucial, as it significantly improves survival rates. The Shield blood test is expected to be commercially available by fall and has the potential to increase screening rates among eligible individuals, ultimately leading to better outcomes for those at risk of CRC.
