Screening

• No history of CRC, IBD, or adenomatous polyps

• No family history of hereditary colon cancer syndromes (e.g., HNPCC, familial adenomatous polyposis)

• All individuals aged > 50 years; recent guidelines suggest starting screening at 45 years of age.

• The decision to continue screening in patients aged > 75 years should be made on a case-by-case basis.

Consider individual risk factors and patient preference when choosing a screening method.

• Direct visualization

  • Gold standard: Complete colonoscopy every 10 years if no polyps or carcinomas are detected

  • Alternatives

    • CT colonography or capsule endoscopy every 5 years [49]

    • Flexible sigmoidoscopy every 5–10 years

• Stool-based testing

  • Annual fecal immunochemical testing (FIT)

    • Uses antibodies to detect occult GI bleeding

    • Has a higher sensitivity for CRC than FOBT

    • All positive stool-based test results need to be confirmed using colonoscopy.

  • Annual fecal occult blood test (FOBT)

    • Used to detect the presence of blood in feces that is not visibly apparent.

    • Used as a screening tool for colorectal carcinoma, but upper gastrointestinal bleeding (e.g., from a peptic ulcer) can also yield positive results

    • A positive result merits additional follow-up (e.g., upper endoscopy, colonoscopy)

    • Has poor sensitivity for detecting polyps

  • Multitargeted stool DNA test every 3 years

    • A stool-based assay that detects certain mutations typical for early colorectal carcinoma, such as mutations of the KRAS gene.

    • Used as a screening tool for colorectal carcinoma

    • Positive tests are followed up with colonoscopy