Available online 5 July 2023, 101848

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Post-polypectomy surveillance has proven to reduce colorectal cancer (CRC) incidence in patients with high-risk polyps, but it implies a major burden on colonoscopy units. Therefore, it should be targeted to individuals with a higher risk. Different societies have published guidelines on surveillance after resection of polyps, with notable discrepancies among them, and many recommendations come from low-quality evidence based on surrogate measures, such as risk of advanced adenoma, and not CRC risk. In this review, we aimed to summarize the evidence supporting post-polypectomy surveillance, compare the recently updated major guidelines, and discuss the existing discrepancies on this topic. Briefly, patients with adenomas ≥10 mm or high-grade dysplasia and patients with serrated polyps ≥10 mm or dysplasia are generally considered to have an increased risk of metachronous CRC and require surveillance, whereas the indication of surveillance is not clearly established in patients without these high-risk features.

Section snippetsBackground

Colorectal cancer (CRC) is one of the most frequent cancers in Western countries, with an increasing incidence and mortality [1,2]. Its natural history is well known, with adenomatous and serrated polyps (SPs) being its precursor lesions, which is why CRC screening programs have increasingly spread [3].

Due to the increasingly widespread use of CRC screening programs, more people are being diagnosed with colonic adenomas and serrated lesions [4]. Some of these individuals are at elevated risk of

Precursor lesions

The genetic factors that lead to CRC are based on genetic instability that favors the accumulation of DNA mutations and epigenetic changes that initiate tumor development and progression. During this process, changes occur in the cells of the colonic epithelium that cause them to obtain a greater proliferative capacity and overcome the mechanisms that regulate cell growth and apoptosis. In most cases, these genetic changes are acquired by somatic mutations, but a small proportion are inherited

Rationale for surveillance

There is evidence that detection and removal of adenomas reduces the incidence and mortality of CRC, with retrospective studies [10,22,23] showing that surveillance significantly reduces the risk of CRC in individuals with high-risk adenomas (HRAs). However, individuals who had colonic adenomas with high-risk features removed at colonoscopy remain at an increased risk of CCR and CCR mortality later in life, with a 2 to 3-fold higher risk than a population with normal colonoscopy [24,25], even

Adherence to guidelines

Despite several guidelines having been published recommending CRC surveillance intervals after index colonoscopy, there is evidence for both under- and over-utilization of surveillance. A recent meta-analysis concluded that worldwide adherence to recommended surveillance intervals was less than 50%, with a predominance of too early repeat colonoscopies [33].

There could be several explanations for the high rates of deviation from recommendations, including inconsistencies among different

Risk stratification

Different scientific societies [[12], [13], [14], [15], [16], [17]] have made recommendations on post-polypectomy surveillance, considering the characteristics of the adenomas (size, multiplicity, high-grade dysplasia [HGD], villous component) or SP (size, histology, presence of dysplasia) that increase the risk of developing metachronous AN.

After high-quality colonoscopy, patients with no neoplasia detected are at the lowest risk, and those with polyps are risk-stratified, with discrepancies

Guideline recommendations on high-risk adenomas

An overview of the main post-polypectomy surveillance intervals after adenoma excision according to major societies is provided in Table 1. Some heterogeneity exists among recommended intervals, which is a consequence of the low to moderate quality of evidence available in this regard. To date, only two randomized controlled trials [39,42] have compared different surveillance intervals, namely 1 or 3 years, and more high-quality studies that compare longer intervals are needed. The European

Guideline recommendations on low-risk adenomas

There is evidence that patients with low-risk lesions (1–2 tubular adenomas with LGD) on colonoscopy who undergo polypectomy do not have a higher risk of metachronous CRC than patients with normal colonoscopy [24] or the general population [50], and even have a lower risk of CRC mortality than the general population after a single colonoscopy with polypectomy of visualized lesions [51]. These data seem to confirm that, given the clear low risk in these patients, a recommendation for no

Guideline recommendations on serrated polyps

An overview of the main post-polypectomy surveillance intervals after polypectomy of serrated lesions according to major societies is provided in Table 2. The heterogeneity among societies is even greater for surveillance recommendations after excision of SP. Of the discussed guidelines, only three (ESGE, USMTF, BSG/ACPGBI/PHE) state clear and explicit guidance.

The BSG/ACPGBI/PHE guideline is the first to consider synchronous adenomas and SP together for risk stratification and surveillance

Second surveillance

The BSG/ACPGBI/PHE guidelines do not recommend later surveillance after no high-risk findings at surveillance. However, most of the current guidelines [[12], [13], [14]] consider both index and first surveillance colonoscopy results when deciding on the second surveillance interval. This recommendation is based on observational studies showing that risk of metachronous AN at the second surveillance depends on the findings of both baseline and first surveillance colonoscopy [[62], [63], [64]].

Special situations

As stated before, surveillance recommendations can only be given after a baseline colonoscopy complete to the cecum with adequate bowel cleansing and resection of all visualized lesions. Assuming this, the main special situation remarked upon in post-polypectomy surveillance guidelines is the piecemeal polypectomy of sessile or flat large polyps.

Large polyps with piecemeal excision are known to be associated with high rates of incomplete resection [65], with up to 55% of piecemeal excisions

Future directions

As detailed above, current guidelines base surveillance recommendations considering the characteristics of the polyps (size, multiplicity, dysplasia, or villous component) that have been classically related to an increased risk of metachronous AN. In this regard, there is still remarkable divergence among guidelines and unanswered questions. Specifically, more studies are required to evaluate the optimal cut-off for adenoma size requiring surveillance (e.g., 10 vs. 20 mm threshold), the

Practice points-

A high-quality baseline colonoscopy is a fundamental prerequisite before any surveillance recommendation.

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Adenomas ≥10 mm in size or high-grade dysplasia and ≥5 adenomas are considered high-risk features in major society guidelines, with a clear recommendation of surveillance at 3 years.

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Serrated polyps ≥10 mm or with dysplasia are considered high-risk lesions in main guidelines, with a recommended surveillance interval of 3–5 years.

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One to two small (<10 mm) adenomas with low-grade dysplasia are

Research agenda-

As post-polypectomy surveillance is one of the main indications of colonoscopy, with the consequent burden on endoscopy units, high-quality studies are needed to elucidate if longer intervals could offer the same level of protection against CRC after resection of high-risk lesions.

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Along the same lines, the relationship between the quality of the baseline exam and surveillance intervals must be investigated, particularly how to implement this relationship in guideline recommendations.

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As

Declaration of competing interest

RJ has received research grants from MSD, and has participated as an advisor to MSD, Norgine, Alpha-Sigma, and GISupply. MDR has no COI since start of 2020 (Advisor for Norgine in 2019). The rest of authors have nothing to disclose.

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© 2023 Published by Elsevier Ltd.