___________________________________________________________________________ Colorectal Cancer
Recommended Colorectal Cancer Screening Intervals Clinicians should select the screening test with the patient on the basis of a discussion of benefits, harms, costs, availability, frequency, and patient preferences. The ACP recommends that patients between 50 and 75 years of age with average risk should be screened [163]: • Every 10 years for colonoscopy • Every 10 years for flexible sigmoidoscopy, plus iFOBT every 2 years • Every 2 years for high-sensitivity gFOBT or iFOBT These recommended intervals, especially for colonoscopy, are based on the assumption of optimal patient preparation and operator performance in the initial screen, allowing removal and biopsy of all polyps and detection of any precancerous lesion. Inadequate colonoscopy performance and resultant failure to detect adenomas or precancerous lesions places the patient at much greater risk of developing colorectal cancer (referred to as interval colorectal cancer) and renders the recommended interval unsafe [132].
RECOMMENDED SURVEILLANCE INTERVALS FOR AVERAGE-RISK PATIENTS a Baseline Colonoscopy Findings Surveillance Interval No polyps (normal) 10 years 1–2 tubular adenomas <10 mm 7 to 10 years 3–10 tubular adenomas <10 mm 3 to 5 years 5-10 tubular adenomas <10 mm 3 years One or more tubular adenomas ≥10 mm 3 years One or more villous adenomas 3 years Adenoma with high-grade dysplasia 3 years <10 adenomas on single examination 1 year Piecemeal resection of adenoma ≥20 mm 6 months Serrated lesions
Sessile serrated polyp(s) <10 mm with no dysplasia ≤20 hyperplastic polyps in rectum or sigmoid colon <10 mm Piecemeal resection of sessile serrated polyp(s) ≥20 mm
10 years
6 months
The National Comprehensive Cancer Network recommends screening for persons at average risk for colorectal cancer begin at 45 years of age after available options have been discussed. Currently, recommended options include: colonoscopy every 10 years;
a Strong recommendation Source: [164]
Table 5
The basis for recommended time intervals between screening and surveillance colonoscopy should involve evidence that examinations prevent interval cancers and cancer-related mortality. Interval diagnosis of advanced adenomas has been used as a surrogate marker for colorectal cancer incidence or mortality. The U.S. Multi-Society Task Force guidelines for post-polypectomy surveillance in average-risk patients emphasize use of baseline colonoscopy findings for risk stratification, which is clustered into two groups [165]: • Low-risk adenomas: One to two tubular adenomas <10 mm • High-risk adenomas: Adenoma with villous histology, high-grade dysplasia, size ≥10 mm, or numbering three or more The British Society of Gastroenterology surveillance guidelines categorizes patients into three risk groups [166]: • Low risk: One to two adenomas <10 mm • Intermediate risk: Three or four small adenomas, or one adenoma ≥10 mm • High risk: More than five small adenomas, or three or more adenomas with at least one ≥10 mm Surveillance at one year was recommended for high-risk patients over concerns of missed lesions at baseline, differing from U.S. guideline emphasis (and assumption) of high-quality baseline examination [164]. This update of surveillance recommendations was developed to address emerging issues in post-colonoscopy surveillance [164].
annual high-sensitivity guaiac-based testing or fecal immunochemical test; multitarget-stool DNA-based testing (every 3 years); flexible sigmoidoscopy every 5 to 10 years; or CT colonography every 5 years. (https://www.nccn.org/professionals/physician_gls/pdf/ colorectal_screening.pdf. Last accessed March 14, 2022.) Level of Evidence : 2a (Based upon lower-level evidence, there is uniform NCCN consensus that the intervention is appropriate.) Recommended Colonoscopy Surveillance after Screening and Polypectomy The timing of follow-up surveillance colonoscopy after initial colorectal cancer screening colonoscopy is an essential component of colorectal cancer prevention ( Table 5 ). Adenomatous polyps are cancer precursor lesions and the most common neoplasm found during colorectal cancer screening. Their detection and removal reduces colorectal cancer incidence and mortality, but patients with adenomas have heightened risk of developing interval cancers (metachronous adenomas or colorectal cancer) within three to five years of colonoscopy and polypectomy [164].
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