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, with all positive non-colonoscopy screening tests followed by timely colonoscopy. 1

Screening Age Recommendations

• Average-risk adults should begin screening at age 45 1
• Continue regular screening through age 75 for those in good health with life expectancy >10 years 1
• For adults aged 76-85, screening decisions should be 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 individuals (first-degree relative with colorectal cancer or advanced adenoma diagnosed before age 60) should begin screening at age 40 or 10 years before the youngest affected relative's diagnosis 1, 2

Recommended Screening Tests

Tier 1 (Preferred) Tests

• Colonoscopy every 10 years 1, 3
• Fecal immunochemical test (FIT) annually 1, 3

Tier 2 Tests

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

Risk Stratification Approach

• For average-risk individuals: Begin screening at age 45 1
• For African Americans: Begin screening at age 45 due to higher disease burden 1, 5
• For high-risk individuals (family history): Begin screening at age 40 or 10 years before the youngest affected relative's diagnosis 1, 2
• For those with two or more first-degree relatives with colorectal cancer: Begin screening earlier and use colonoscopy 5

Implementation Considerations

• All positive results from non-colonoscopy screening tests must be followed up with timely colonoscopy 1
• Patient preference should be considered when selecting a screening method 1
• Quality indicators for colonoscopy should be monitored (cecal intubation rates, withdrawal time, adenoma detection rates) 1

When to Stop Screening

• Discontinue screening in adults aged 75+ who are up-to-date with prior negative screening results 1, 6
• For adults aged 76-85, individualize decisions based on overall health status, prior screening history, and life expectancy 1
• Screening is not recommended for adults over age 85 1

Common Pitfalls and Caveats

• Failure to follow up positive stool-based tests with colonoscopy negates the benefit of screening 1
• Inadequate bowel preparation can reduce colonoscopy effectiveness 1
• Discontinuing screening too early in healthy individuals or continuing too long in those with limited life expectancy can lead to unnecessary risks 1
• Variability in colonoscopy quality can significantly impact screening effectiveness 1
• Rising colorectal cancer incidence in persons under age 50 necessitates thorough diagnostic evaluation of young persons with suspected colorectal bleeding 3

Screening Test Selection Strategy

• Consider a sequential approach: offer colonoscopy first, then FIT to patients who decline colonoscopy 3
• A risk-stratified approach is appropriate: FIT screening in populations with estimated low prevalence of advanced neoplasia and colonoscopy screening in high prevalence populations 3
• The most recent guidelines discourage the use of Septin9 serum assay for screening 3