What are the recommended screening guidelines for colorectal cancer (CRC) in an average-risk individual?

Colorectal Cancer Screening Recommendations

Average-risk adults should begin colorectal cancer screening at age 45 years using either colonoscopy every 10 years or annual fecal immunochemical testing (FIT) as first-tier options, with screening continuing through age 75 years in those with good health and life expectancy exceeding 10 years. 1, 2

When to Start Screening

Begin at age 45 years for all average-risk individuals, though this carries a qualified recommendation. 1, 2 The recommendation to start at age 45 is based on a 51% increase in CRC incidence among adults younger than 55 years from 1994 to 2014, and an 11% increase in mortality from 2005 to 2015 in this age group. 1

The recommendation becomes stronger at age 50 years, where screening carries a strong recommendation with high-quality evidence for mortality reduction. 1, 2

First-Tier Screening Options

Colonoscopy every 10 years is the preferred structural examination, as it uniquely detects and removes precancerous polyps during the same procedure, directly preventing cancer development rather than merely detecting existing disease. 1, 2, 3, 4 High-quality colonoscopy requires:

• Cecal intubation rates exceeding 90% 2
• Withdrawal time of at least 6 minutes 2
• Adenoma detection rates of at least 25% in men and 15% in women over 50 2

Annual FIT is the other first-tier option with proven mortality benefit. 1, 2, 5, 4 Annual testing commitment is essential—one-time or sporadic FIT testing has very limited sensitivity and makes stool testing a poor screening choice. 5

Second-Tier Screening Options

When patients decline both colonoscopy and FIT, offer these alternatives: 1, 2

• Multitarget stool DNA test (FIT-DNA/Cologuard) every 3 years 1, 2, 3
• CT colonography every 5 years 1, 2
• Flexible sigmoidoscopy every 5-10 years 1, 2

Note that Cologuard has 87% specificity compared to 95% for FIT, resulting in 13-40% false-positive rates that lead to unnecessary colonoscopies. 3 A negative colonoscopy provides 10 years of protection versus 3 years for Cologuard. 3

Critical Follow-Up Requirement

All positive results on non-colonoscopy screening tests must be followed by timely diagnostic colonoscopy. 1, 2, 5 This is non-negotiable for the screening program to be effective.

When to Stop Screening

Stop screening at age 75 years for patients who are up-to-date with prior negative screening tests, particularly those with negative colonoscopy. 1, 2, 5

For ages 76-85 years, continue screening only if: 1, 2, 5

• Life expectancy exceeds 10 years
• Patient has good overall health status
• Patient has not had adequate prior screening

Discontinue screening at age 85 years regardless of prior screening history, as harms outweigh benefits. 1, 2, 5

Stop screening at any age when life expectancy falls below 10 years due to comorbidities. 1, 2, 5

Higher-Risk Individuals Requiring Earlier/More Frequent Screening

For first-degree relative with CRC or advanced adenoma diagnosed before age 60, or two first-degree relatives at any age: 2, 4

• Begin colonoscopy at age 40 OR 10 years before the youngest affected relative's diagnosis, whichever comes first
• Repeat colonoscopy every 5 years

For single first-degree relative diagnosed at age 60 or older: 4

• Begin average-risk screening options at age 40 years

Sequential Screening Strategy for Maximum Uptake

The most effective real-world approach is sequential offering, which achieves similar overall adherence but results in higher colonoscopy uptake: 3

1. First offer colonoscopy every 10 years
2. If declined, offer annual FIT
3. If declined, offer Cologuard every 3 years
4. If declined, offer CT colonography every 5 years or flexible sigmoidoscopy every 5-10 years

Common Pitfalls to Avoid

Do not offer sporadic or one-time FIT testing—this undermines the entire screening program's effectiveness. 5 Patients must commit to annual testing.

Do not continue screening beyond age 85 years or when life expectancy is less than 10 years, as the harms of screening (perforation, bleeding, complications from sedation) outweigh any potential mortality benefit. 1, 2, 5

Do not fail to follow up positive non-colonoscopy tests with colonoscopy—this represents a critical breakdown in the screening cascade that can result in missed cancers. 1, 2, 5