List criteria for average risk of CRC.
No history of CRC, IBD, or adenomatous polyps
No family history of hereditary colon cancer syndromes (e.g., HNPCC, familial adenomatous polyposis)
What is the recommended screening age?
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.
Describe the screening modalities.
Consider individual risk factors and patient preference when choosing a screening method.
Gold standard: Complete colonoscopy every 10 years if no polyps or carcinomas are detected
CT colonography or capsule endoscopy every 5 years 
Flexible sigmoidoscopy every 5–10 years
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