Recommended colorectal cancer (CRC) screening modalities fall into two broad categories: invasive (direct visualization of the colon) and noninvasive (stool-based testing and blood-based testing in development). Stool testing, involving chemical analysis of fecal matter for blood and/or other molecular markers of abnormal cell growth,1 is a less invasive screening option.2
Stool-Based Tests: Efficacy and Considerations3
Method | Evidence of Efficacy | Other Considerations |
---|---|---|
High-Sensitivity gFOBT |
|
|
FIT |
|
|
sDNA-FIT |
|
Table adapted from Davidson, 20213
Sensitivity and Specificity of Screening Tests3
Test | Sensitivityf | Specificityf |
---|---|---|
High-Sensitivity gFOBT (CRC)a | 0.50-0.75 | 0.96-0.98 |
FIT (CRC)b | 0.74g | 0.94g |
sDNA-FIT(CRC)c | 0.93g | 0.84g |
Colonoscopy (adenomas 10 mm or larger)d | 0.89-0.95 | 0.89 |
CT Colonography (CRC)e | 0.86-1.00 | Not reported |
CT Colonography (adenomas 10 mm or larger)e | 0.89g | 0.94g |
- Stool tests require no bowel preparation, no sedation, and are noninvasive2,3
- The United States Preventive Services Task Force recommendations note that for sDNA-FIT, there is insufficient evidence about appropriate longitudinal follow-up of abnormal findings after a negative diagnostic colonoscopy, and there is no direct evidence evaluating effect of sDNA-FIT on CRC mortality3
- Note: Guidelines and recommendations may refer to the Cologuard® test (mt-sDNA) as different names, including FIT-fecal DNA, sDNA, and sDNA-FIT
- All positive results on noncolonoscopy screening tests should be followed up with a timely colonoscopy1,3-5
- The recommendations note that there is no direct evidence evaluating the effect of CT colonography on CRC mortality; there is limited evidence about the potential benefits or harms of possible evaluation and treatment of incidental extracolonic findings, which are common3
- Extracolonic findings are detected in 1.3% to 11.4% of exams, but ≤3% require medical or surgical treatment3
Direct Visualization: Efficacy and Considerations3
Method | Evidence of Efficacy | Other Considerations |
---|---|---|
Colonoscopy |
|
|
CT Colonography |
|
|
Flexible Sigmoidoscopy |
|
|
Flexible Sigmoidoscopy With FIT |
|
|
Table adapted from Davidson, 20213
Estimated Complications of CRC Screening and Follow-Up Procedures Per 100 Individuals Screening (2021)3,h,i
Screening Method and Frequency | Age 50 | Age 45 |
---|---|---|
Stool tests | ||
FIT every year | 10 | 11 |
HSgFOBT every yearj,k | 9 | 10 |
sDNA-FIT every year | 12 | 13 |
sDNA-FIT every 3 yearsk | 10 | 10 |
Direct visualization tests | ||
Colonoscopy every 10 years | 14 | 16 |
CT colonoscopy every 5 years | 11 | 11 |
Flexible SIG every 5 years | 11 | 11 |
Flexible SIG every 10 years plus FIT every year | 12 | 13 |
Table adapted from Davidson, 20213
Complications per 1000 Screeners, by Age to Begin Screening
- Harms from stool-based screening arise from colonoscopy to follow-up abnormal results3
Footnotes
- Data for gFOBT were collected from 2 studies (n=3503).3
- Data for FIT were taken from 13 studies (n=44,887) of OC-Sensor family of FITs.3
- Data for sDNA-FIT were based on 4 studies (n=12,424).3
- Sensitivity data for colonoscopy came from 4 studies (n=4821), and specificity was reported from a single study.3
- Data for CT colonography were based on 7 studies (n=5328).3
- 95% confidence interval reported for all values.3
- Estimates are derived from modeling completed by the Cancer Intervention and Surveillance Modeling Network (CISNET) to inform the 2021 USPSTF recommendations.3
- Outcomes are expressed per 1000 40-year-olds who start screening at age 45 or at age 50.3
- Average estimate across the 3 CISNET colorectal cancer models. See modeling report for additional details and model-specific estimates.3
- Due to imprecision in sensitivity and specificity, there is considerable uncertainty in model predictions for HSgFOBT strategies. See modeling report for more information.3
- Compared to other options for stool-based screening, these strategies do not provide an efficient balance of the benefits (life-years gained) vs harms and burden (i.e., lifetime no. of colonoscopies) of screening. See modeling report for more information.3
List of definitions
CISNET: Cancer Intervention and Surveillance Modeling Network; CRC: colorectal cancer; CT: computed tomography; FIT: fecal immunochemical test; gFOBT: guaiac-based fecal occult blood test; HSgFOBT: high-sensitivity guaiac-based fecal occult blood test; mt-sDNA: multitarget stool DNA; RCT: randomized controlled trial; sDNA: stool DNA; sDNA-FIT: multitarget stool DNA test with fecal immunochemical test; SIG: sigmoidoscopy; US: United States; USPSTF: United States Preventive Services Task Force.
References
- Wolf AMD, Fontham ETH, Church TR, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society. CA Cancer J Clin. 2018;68(4):250-281.
- American Cancer Society. Colorectal cancer screening tests. Updated June 29, 2020. Accessed May 14, 2024. https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html
- Davidson KW, Barry MJ, Mangione CM, et al; US Preventive Services Task Force. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(19):1965-1977.
- Patel SG, May FP, Anderson JC, et al. Updates on age to start and stop colorectal cancer screening: recommendations from the US Multi-Society Task Force on Colorectal Cancer. Gastroenterol. 2022;162(1):285-299.
- Shaukat A, Kahi CJ, Burke CA, et al. ACG clinical guidelines: colorectal cancer screening 2021. Am J Gastroenterol. 2021;116:458-479.