Blood testing is now included in screening recommendations for colon and rectal cancer

Key Points:

• The American Cancer Society has updated its colorectal cancer screening guidelines to include blood-based tests, specifically recommending the FDA-approved Shield test for adults aged 45 and older at average risk who decline or do not complete visual exams or stool tests.
• Colonoscopies remain the gold standard due to their high sensitivity and ability to detect and remove precancerous polyps, but blood tests offer a less invasive alternative that may increase screening rates among those unwilling or unable to undergo traditional screening methods.
• The Shield blood test detects tumor DNA with about 83% sensitivity for colorectal cancer but is less effective at identifying early-stage cancers and precancerous lesions, so it is advised only as a secondary option after other screening methods.
• Stool-based tests such as Cologuard Plus and the newly FDA-approved ColoSense remain recommended options, with high sensitivity and specificity, and are typically covered by insurance, though costs may be a barrier for uninsured individuals.
• Colorectal cancer incidence is rising in younger adults, and while screening is recommended starting at age 45, the American Cancer Society continues to evaluate whether to lower this age further; however, blood-based tests are not yet recommended for those under 45 due to limited evidence.