For referring providers · Colorectal cancer screening - A community standard
Comparative performance of colonoscopy, stool DNA, and blood-based screening tests
Colonoscopy Prevents Colorectal Cancer
The other stool- and blood-based tests just find it sometimes
The data below makes the case for a single, evidence based standard for colon cancer screening and actual prevention — Colonoscopy.
Sensitivity for Advanced Precancerous Lesions
The lesions that, if found, and removed, prevent cancer
| Test | CRC Sensitivity | Specificity | Interval | Prevents Cancer (removes polyps) |
|---|---|---|---|---|
| Colonoscopy | ~95% | ~86–90% | 10 years | Yes |
| Cologuard Plus | 93.9% | 90.6% | 3 years | No |
| Shield (blood) | 83.1% | 89.6% | 3 years | No |
| FIT | 67.3% | 94.8% | 1 year | No |
Sources: Knudsen & Lin et al., JAMA 2021 · Imperiale et al., NEJM 2024 · Burke et al., AGA 2022 · Chung et al., NEJM 2024
Every guideline agrees: a positive noninvasive test is only useful if it is followed by prompt colonoscopy — per NCCN, no later than 9 months. An abnormal result with no follow-up colonoscopy provides false reassurance and is worse than no screening at all.
Lead with colonoscopy
Offer and recommend it as the preferred test for average-risk patients — it detects and prevents cancer in one visit.
Rank the alternatives
For patients unfit for, or decline colonoscopy: stool DNA before blood-based testing, with counseling on their lower sensitivity for precancerous lesions.
Close the loop
Track every abnormal result to a completed diagnostic colonoscopy through a shared navigation process.