From the Guidelines
Colorectal Cancer (CRC) Screening Guidelines: The general consensus is that average-risk adults should be screened for CRC, with most guidelines recommending screening between the ages of 50 and 75 years 1.
Key Recommendations
- Screening Age: The American Cancer Society recommends starting screening at age 45 years in all average-risk individuals 1, while other guidelines recommend starting at age 50 years 1.
- Screening Tests: Recommended tests include stool-based tests (fecal immunochemical test [FIT], guaiac-based fecal occult blood test, and the multi-target stool DNA test), and structural examinations (colonoscopy, flexible sigmoidoscopy, computed tomography colonography [CTC]) 1.
- Screening Intervals: Suggested screening intervals are every 2 years for stool-based tests and every 10 years for colonoscopy or flexible sigmoidoscopy plus fecal immunochemical testing every 2 years 1.
- Stopping Age: Most guidelines recommend stopping screening at age 75 years, with decisions about screening beyond that age needing to be individualized and based on factors including overall health and screening history 1.
Considerations
- Risk Factors: Patients with a family history of CRC, genetic syndromes, or a personal history of CRC or adenomatous polyps are considered to have above-average risk and may require earlier or more frequent screening 1.
- Individualized Screening: Decisions about screening should be individualized and based on a discussion of benefits, harms, costs, availability, and patient preferences 1.
- Personalized Screening: There is a need to move towards personalized CRC screening, taking into account individual risk factors and preferences 1.
From the Research
Guidelines for Colorectal Cancer Screening
The guidelines for colorectal cancer (CRC) screening recommend screening starting at age 45-50 for average-risk individuals 2, 3, 4. The screening tests for CRC are divided into:
- Stool-based tests, such as fecal immunochemical test (FIT) and high-sensitivity guaiac fecal occult blood test (HSgFOBT) 5, 3
- Endoscopic tests, such as colonoscopy, flexible sigmoidoscopy, and computed tomographic (CT) colonography (virtual colonoscopy) 2, 5, 3
- Molecular tests, such as multi-target stool DNA (mt-sDNA) test 3
Screening Recommendations
The recommended screening strategies include:
- Colonoscopy and FIT tests as standard modalities for regular screening 2
- Screening with one of several screening strategies, including HSgFOBT, FIT, mt-sDNA test, CT colonography, flexible sigmoidoscopy, flexible sigmoidoscopy with FIT, or traditional colonoscopy 3
- Consideration of patient- and healthcare-related factors, such as invasiveness of the test, test performance, screening interval, accessibility, and cost 3
Emerging Screening Modalities
There are several emerging and novel CRC screening modalities that are not yet approved for first-line screening in average-risk individuals, including:
- Blood-based screening or "liquid biopsy" 3
- Colon capsule endoscopy 5, 3
- Urinary metabolomics 3
- Stool-based microbiome testing for the detection of colorectal polyps and/or CRC 3
Implementation of Screening Programs
To maximize CRC screening uptake, patients and providers should engage in informed decision-making about the benefits and limitations of recommended screening options 3. Health systems should have a programmatic approach to CRC screening, which may include evidence-based strategies such as patient education, provider education, mailed screening outreach, and/or patient navigation, to maximize screening participation 3. Increasing public awareness of the importance of screening and implementing mass national screening programs can detect early CRC and decrease related mortality 2.