A new colorectal cancer blood test shows promise, but the American Gastroenterological Association says it's not a substitute for colonoscopy.
A study published March 14 in The New England Journal of Medicine assessed the performance of a cell-free DNA blood-based test in a population eligible for colorectal cancer screening in identifying colorectal cancer.
According to the clinical validation study, the blood-based test had an 83% sensitivity rate for colorectal cancer cancers, 90% specificity for advanced neoplasia, and a 13% sensitivity for advanced precancerous lesions.
While the blood test shows promise in helping patients adhere to screening guidelines and avoid uncomfortable colonoscopy procedures, the American Gastroenterological Association warns that blood tests should not be used in place of traditional colonoscopies.
"Having data on a new blood-based screening test for colorectal cancer is exciting. If approved, it will help identify people who will need to undergo colonoscopy to confirm the diagnosis and ultimately help save lives. There is still much to learn, too," the AGA wrote in a March 14 press release. "Colonoscopies allow detection and removal of precancerous polyps as well as identifying cancer early when it is in the most treatable stages. The blood test reported in The New England Journal of Medicine study is only designed to pick up cancers and not precancerous polyps."
CMS will cover blood tests for colorectal cancer screening every three years if the test achieves 74% sensitivity for CRC, 90% specificity and FDA approval, according to the release.
"However, a blood test that meets only the CMS criteria, will be inferior to current recommended tests and should not be recommended to replace current tests," the AGA says. "Blood tests are not interchangeable with colonoscopy for colorectal cancer screening but should prove to be an additional tool to help identify colorectal cancer early."