Colorectal Cancer Screening Guidelines
Average-risk adults should begin colorectal cancer screening at age 45 years with either colonoscopy every 10 years or annual fecal immunochemical testing (FIT) as first-tier options, continuing through age 75 years if in good health with life expectancy exceeding 10 years. 1, 2
Screening Initiation by Risk Category
Average-Risk Adults
- Begin screening at age 45 years for all average-risk adults, representing a qualified recommendation based on rising CRC incidence in younger populations 1, 2, 3
- The recommendation strengthens to a strong recommendation at age 50 years 1
- African Americans should begin at age 45 years due to higher disease burden and mortality rates 4, 2
High-Risk Adults with Family History
- Start colonoscopy at age 40 years OR 10 years before the youngest affected relative's diagnosis (whichever comes first) for individuals with: 4, 2, 3, 5
- First-degree relative with CRC or advanced adenoma diagnosed before age 60
- Two or more first-degree relatives with CRC or advanced adenoma at any age
- Repeat colonoscopy every 5 years in these higher-risk patients 3, 5
- Single first-degree relative diagnosed at age ≥60 can follow average-risk screening starting at age 40 5
Other High-Risk Conditions
- Personal history of inflammatory bowel disease requires individualized surveillance 4
- Hereditary syndromes (Lynch syndrome, familial adenomatous polyposis) require specialized protocols 4
First-Tier Screening Options
Colonoscopy every 10 years and annual FIT are the cornerstone screening tests regardless of approach 2, 3, 5
Colonoscopy
- Preferred interval: every 10 years 1, 2, 3
- Allows simultaneous detection and removal of precancerous polyps 1
- Quality metrics must be monitored: 2, 3
- Cecal intubation rate >90%
- Withdrawal time ≥6 minutes
- Adenoma detection rate ≥25% in men, ≥15% in women over 50
Fecal Immunochemical Test (FIT)
- Frequency: annually 1, 2, 3
- High-sensitivity, non-invasive option 1
- Critical caveat: All positive FIT results MUST be followed by timely diagnostic colonoscopy 1, 2, 3
Second-Tier Screening Options
These tests are appropriate alternatives but have disadvantages relative to first-tier options 5:
- High-sensitivity guaiac-based fecal occult blood test (HSgFOBT): annually 1, 2
- Multitarget stool DNA test (mt-sDNA/FIT-DNA): every 3 years 1, 2, 3
- CT colonography: every 5 years 1, 2
- Flexible sigmoidoscopy: every 5 years (or every 10 years with annual FIT) 1, 2, 5
When to Stop Screening
Age-Based Discontinuation
- Stop routine screening at age 75 years for adults in good health who are up-to-date with prior negative screening 1, 2, 3
- Ages 76-85 years: Screen only if no prior screening history; otherwise discontinue based on health status and life expectancy 1, 2
- Strongly discourage screening after age 85 years as harms outweigh benefits 1, 2, 3
Life Expectancy Considerations
- Discontinue screening when life expectancy falls below 10 years, regardless of age 2, 3, 6
- This applies to adults with significant comorbidities even if younger than 75 6
Critical Implementation Requirements
Follow-Up of Positive Tests
- All positive non-colonoscopy screening tests require timely diagnostic colonoscopy 1, 2, 3
- Failure to follow up positive stool-based tests negates screening benefits 2
Quality Assurance for Colonoscopy
Physicians must measure and report: 2, 3
- Cecal intubation rates (target >90%)
- Withdrawal time (minimum 6 minutes)
- Adenoma detection rates (≥25% men, ≥15% women)
- Appropriate follow-up intervals
- Complication rates
Common Pitfalls to Avoid
- Inadequate bowel preparation reduces colonoscopy effectiveness 2
- Discontinuing screening too early in healthy individuals misses potential benefit 2
- Continuing screening too long in those with limited life expectancy creates unnecessary risk 2
- Variability in colonoscopy quality significantly impacts screening effectiveness 2
Sequential Screening Approach
When offering screening sequentially: 5
- Offer colonoscopy first
- If patient declines colonoscopy, offer annual FIT as alternative
- Ensure patient understands that positive FIT requires colonoscopy follow-up
Risk-Stratified Approach
Alternative strategy based on population prevalence: 5