In 2024, the FDA granted approval to the Shield test by Guardant, a cfDNA blood-based test. Using a blood draw, the test looks for cancer and pre-cancerous cells. Blood tests are highly effective at detecting colorectal cancer and have similar rates to other non-invasive tests for colorectal cancer screening. This means these tests have a high percentage of correctly identifying those who do not have colorectal cancer.

Blood tests are not as effective at identifying pre-cancerous polyps compared to many of the stool-based tests like FIT or mt-sDNA, or colonoscopy.

Many medical professionals are advising patients to understand the blood test is strong in early detection of cancer, but not cancer prevention. Colorectal cancer is a highly preventable cancer, as pre-cancerous polyps can be removed before cancer grows.

  • A simple blood draw
  • Needs repeated every 1-3 years
  • If you receive a positive result, a follow-up colonoscopy is necessary.
  • May not be covered by insurance since it’s not yet included in screening guidelines.

It is best to call your insurance provider to determine screening tests that are and are not covered, and to work with your doctor on the best screening plan for you.