What are the guidelines for colon cancer screening?

Colorectal Cancer Screening Guidelines

Average-risk adults should begin colorectal cancer screening at age 45 with either a high-sensitivity stool-based test or a structural examination, continuing through age 75 if in good health with life expectancy >10 years. 1

Screening Age Recommendations

• Screening should begin at age 45 for average-risk adults 1
• African Americans should begin screening at age 45 due to higher disease burden 1, 2
• High-risk individuals should begin screening at age 40 or 10 years before the youngest affected relative's diagnosis, whichever comes first 1, 2, 3
• Continue regular screening through age 75 for those in good health with life expectancy >10 years 1, 4
• For adults aged 76-85, screening decisions should be individualized based on patient preferences, life expectancy, health status, and prior screening history 1
• Screening is generally not recommended for adults over age 85 1

High-Risk Factors

• First-degree relative with colorectal cancer or advanced adenoma diagnosed before age 60 1, 2
• Two or more first-degree relatives with colorectal cancer or advanced adenoma at any age 2, 4
• Personal history of inflammatory bowel disease 2
• Hereditary syndromes such as Lynch syndrome or familial adenomatous polyposis 2

Recommended Screening Tests

Tier 1 (Preferred) Tests

• Colonoscopy every 10 years 1, 4
• Fecal immunochemical test (FIT) annually 1, 4

Tier 2 Tests

• High-sensitivity guaiac-based fecal occult blood test (HSgFOBT) annually 1, 4
• Multitarget stool DNA test (mt-sDNA/FIT-DNA) every 3 years 1, 4
• CT colonography every 5 years 1, 5
• Flexible sigmoidoscopy every 5 years 1, 5

Implementation Algorithm

1. Risk Assessment:

   • Determine if patient is average-risk or high-risk 2
   • If high-risk, recommend colonoscopy starting at age 40 or 10 years before youngest affected relative's diagnosis 1, 2

2. For Average-Risk Individuals:

   • Begin screening at age 45 1
   • Offer Tier 1 tests first (colonoscopy every 10 years or annual FIT) 1, 4
   • If patient declines Tier 1 tests, offer Tier 2 alternatives 4

3. Follow-Up Protocol:

   • All positive results from non-colonoscopy screening tests must be followed up with timely colonoscopy 1
   • Failure to follow up positive stool-based tests with colonoscopy negates the benefit of screening 1

4. Screening Discontinuation:

   • Consider discontinuing screening at age 75 for those up-to-date with prior negative screening 1, 4
   • For adults 76-85, individualize decision based on overall health status and prior screening history 1
   • Generally discontinue screening after age 85 1

Quality Considerations

• Colonoscopy quality should be monitored using indicators such as cecal intubation rates, withdrawal time, adenoma detection rates, and complication rates 1
• Inadequate bowel preparation can significantly reduce colonoscopy effectiveness 1
• Patient preference is an important consideration when selecting a screening method 1, 6

Common Pitfalls to Avoid

• Failing to follow up positive stool-based tests with colonoscopy 1
• Discontinuing screening too early in healthy individuals or continuing too long in those with limited life expectancy 1
• Not recognizing the rising incidence of colorectal cancer in persons under age 50, requiring thorough diagnostic evaluation of young persons with suspected colorectal bleeding 4
• Overlooking the importance of colonoscopy quality, which can significantly impact screening effectiveness 1