July 29, 2024 – A breakthrough in medical testing now allows for colorectal cancer screening with just a simple blood test, promising a more accessible and less invasive way to catch the disease early.
The FDA on Monday approved the test, called Shield, which can accurately detect tumors in the colon or rectum about 87% of the time when the cancer is in treatable early stages. The approval was announced Monday by the test’s maker, Guardant Health, and comes just months after promising clinical trial results were published in The New England Journal of Medicine.
Colorectal cancer is among the most common types of cancer diagnosed in the U.S. each year, along with being one of the leading causes of cancer deaths. The condition is treatable in early stages, but about 1 in 3 people don’t stay up to date on regular screenings, which should begin at age 45.
The simplicity of a blood test could make it more likely for people to be screened for and, ultimately, survive the disease. Other primary screening options include feces-based tests or colonoscopy. The 5-year survival rate for colorectal cancer is 64%.
While highly accurate at detecting DNA shed by tumors during treatable stages of colorectal cancer, the Shield test was not as effective at detecting precancerous areas of tissue, which are typically removed after being detected.
In its news release, Guardant Health officials said they anticipate the test to be covered under Medicare. The out-of-pocket cost for people whose insurance does not cover the test has not yet been announced. The test is expected to be available by next week, The New York Times reported.
If someone’s Shield test comes back positive, the person would then get more tests to confirm the result. Shield was shown in trials to have a 10% false positive rate.
"I was in for a routine physical, and my doctor asked when I had my last colonoscopy," said John Gormly, a 77-year-old business executive in Newport Beach, CA, according to a Guardant Health news release. "I said it's been a long time, so he offered to give me the Shield blood test. A few days later, the result came back positive, so he referred me for a colonoscopy. It turned out I had stage II colon cancer. The tumor was removed, and I recovered very quickly. Thank God I had taken that blood test."
