Surveillance of colonic polyps: Are we getting it right?

Table 1 British Society of Gastroenterology guidelines 2010[79], supported by the 2011 guidelines of The National Institute for Health and Care Excellence

Risk of colorectal cancer or advanced adenomas (≥ 1 cm as measured at endoscopy or high-grade dysplasia)

Patients with only one or two small (< 1 cm) adenomas are at low risk, and need no colonoscopic surveillance or 5-yearly until one negative examination then cease surveillance. Recommendation grade: B

Patients with three or four small adenomas or at least one adenoma ≥ 1 cm are at intermediate risk and should be screened 3-yearly until two consecutive examinations are negative. Recommendation grade: B

If either of the following is detected at any single examination (at baseline or follow-up): five or more adenomas, or three or more adenomas at least one of which is ≥ 1 cm, the patient is at high risk and an extra examination should be undertaken at 12 mo before returning to 3-yearly surveillance. Recommendation grade: B

Patients can be offered surveillance until age 75 yr and thereafter continue depending on relative cancer risk and comorbidity. Colonoscopy is likely to be less successful and more risky at older ages. Further, the average lead time for progression of an adenoma to cancer is 10 yr which is of the same order as the average life expectancy of an individual aged 75 yr or older, suggesting that most will not benefit from surveillance. Recommendation grade: B

These guidelines are based on accurate detection of adenomas, otherwise risk status will be underestimated. Patients with a failed colonoscopy, for whatever reason, should undergo repeat colonoscopy or an alternative complete colonic examination. Recommendation grade: B

The site of large sessile adenomas removed piecemeal should be re-examined at 2-3 mo. Small areas of residual polyp can then be treated endoscopically, with a further check for complete eradication in 2-3 mo. India ink tattooing aids recognition of the polypectomy site at follow-up. If extensive residual polyp is seen, surgical resection needs to be considered, or alternatively referral to a colonoscopist with special expertise in advanced polypectomy techniques. If there is complete healing of the polypectomy site, then there should be a colonoscopy at 1 yr, to check for missed synchronous polyps, before returning to 3 yearly surveillance. Recommendation grade: B

Table 2 American Gastroenterological Association 2012[80]

Findings at index procedure	Suggested surveillance interval	Strength of evidence
No polyps/small (< 10 mm) rectosigmoid hyperplastic	10 yr	Moderate
1-2 small (< 10 mm) tubular adenomas	5–10 yr	Moderate
3-10 tubular adenomas	3 yr	Moderate
> 10 adenomas	< 3 yr	Moderate
One tubular adenoma ≥ 10 mm	3 yr	High
One villous adenoma	3 yr	Moderate
Adenoma with high grade dysplasia (HGD)	3 yr	Moderate
Serrated lesions
Sessile serrated polyp (SSP) < 10 mm with no dysplasia	5 yr	Low
SSP ≥ 10 mm OR with dysplasia OR serrated adenoma	3 yr	Low
Serrated polyposis syndrome	1 yr	Moderate

Table 3 European Society of Gastrointestinal Endoscopy 2013[81]

The following recommendations for post-polypectomy endoscopic surveillance should be applied only after a high quality baseline colonoscopy with complete removal of all detected neoplastic lesions

In the low risk group (patients with 1-2 tubular adenomas < 10 mm with low grade dysplasia), the European Society of Gastrointestinal Endoscopy (ESGE) recommends participation in existing national screening programmes 10 yr after the index colonoscopy. If no screening programme is available, repetition of colonoscopy 10 yr after the index colonoscopy is recommended (strong recommendation, moderate quality evidence)

In the high risk group (patients with adenomas with villous architecture or high grade dysplasia or ≥ 10 mm in size, or ≥ 3 adenomas), the ESGE recommends surveillance colonoscopy 3 yr after the index colonoscopy (strong recommendation, moderate quality evidence). Patients with 10 or more adenomas should be referred for genetic counselling (strong recommendation, moderate quality evidence)

In the high risk group, if no high risk adenomas are detected at the first surveillance examination, the ESGE suggests a 5-yr interval before a second surveillance colonoscopy (weak recommendation, low quality evidence). If high risk adenomas are detected at first or subsequent surveillance examinations, a 3-yr repetition of surveillance colonoscopy is recommended (strong recommendation, low quality evidence)

The ESGE recommends that patients with serrated polyps < 10 mm in size with no dysplasia should be classified as low risk (weak recommendation, low quality evidence). The ESGE suggests that patients with large serrated polyps (≥ 10 mm) or those with dysplasia should be classified as high risk (weak recommendation, low quality evidence)

The ESGE recommends that the endoscopist is responsible for providing a written recommendation for the post-polypectomy surveillance schedule (strong recommendation, low quality evidence)

Table 4 Adenoma surveillance

Findings at index procedure	Suggested initial surveillance interval
No adenomas	No surveillance
1-2 adenomas with no advanced neoplasia	No surveillance
3-4 adenomas with no advanced neoplasia	3 yr
≥ 3 adenomas and advanced neoplasia	1 yr
≥ 5 adenomas	1 yr