Making a resect-and-discard strategy work for diminutive colorectal polyps: let's get real

In this issue of Endoscopy, Taghiakbari et al. report that assigning the histology of diminutive colorectal polyps by colon location alone produced greater agreement with surveillance intervals determined by pathology than surveillance intervals determined by optical diagnosis of diminutive colorectal polyps [1]. The location-based resect-and-discard (LBRD) strategy was simple: everything that is diminutive proximal to the sigmoid is considered an adenoma, and everything diminutive in the rectosigmoid is hyperplastic. The result highlights the limitations of optical diagnosis [2], which might soon be overcome by artificial intelligence predictions of histology.

Although this study seems to define a path forward for resect and discard, it is worth recalling that resect and discard is barely implemented in the USA, even in academic centers where optical diagnosis has resulted in surveillance interval assignments that exceed the American Society for Gastrointestinal Endoscopy PIVI (Preservation and Incorporation of Valuable endoscopic Innovations) thresholds [2] [3]. This editorial discusses the issues raised by the current study, and some not addressed by this study, that block meaningful implementation of the resect-and-discard strategy.

The first of these is the issue of assignment of correct intervals using the LBRD strategy in the current study. Unlike in many countries, the Multi-Society Task Force (MSTF) provides options for surveillance for one or two low risk conventional adenomas, these being 5–10 years in the 2012 recommendations [4] and 7–10 years in the 2020 version. A new interval of 3–5 years for three or four low risk adenomas was introduced in 2020 [5]. In the LBRD study, patients with one or two proximal diminutive polyps were assigned an interval of 10 years, and this was counted as correct. The problem here is that most US endoscopists will repeat the colonoscopy in patients with one or two diminutive adenomas at the shorter end of the recommended interval, meaning at 7 years, and similarly at 3 years for those with three or four adenomas.

“Recommendations from professional endoscopy societies and local institutional policies should change from “you can do resect and discard” to “you should do resect and discard.”

Taghiakbari et al. could have reported the accuracy of LBRD in assigning patients with one or two adenomas to the 7-year interval, among others, which would then allow us to understand how the LBRD strategy would actually satisfy American practice. As some countries have abandoned surveillance or any colonoscopy interval other than 10 years for low risk adenomas [6] [7], the LBRD strategy might work better outside the USA.

The real problem with resect and discard may not be the percentage of cases assigned the correct surveillance interval, but the fear that a cancer will be resected and thrown away. This fear defies evidence-based rational decision-making. For example, in the current study, not a single diminutive polyp among 878 lesions had high grade dysplasia or cancer [1]. Based on literature review and our own data, the risk of invasive cancer in lesions ≤ 5 mm is 0.009 % [8]. However, the perceived medicolegal risk is frequently driven by anecdote. Therefore, gastroenterologists all know that post-colonoscopy cancers occur, and that missed lesions are the main cause [9]. That might not stop a plaintiff from claiming that cancer arose in a diminutive lesion that was thrown away, leading to incomplete treatment. If a colonoscopist holds that concern, why would they risk throwing lesions away when there is no financial incentive for doing so? That brings us the third obstacle to resect and discard, which is that there are no financial incentives for participating in the paradigm.

In the USA, the combination of increased real or perceived medicolegal risk, plus a lack of financial incentive, is the death knell for a new management paradigm. Consider the example of propofol administration under endoscopist supervision without specialist anesthesia involvement. This practice had overwhelming evidence of safety [10], and was endorsed in gastroenterology guidelines [11]. It was quashed by real medicolegal risk, plus the absence of financial incentive for endoscopists [12]. Similarly, for most US endoscopists, there is neither reimbursement for using image-enhanced endoscopy nor financial incentive for implementing a resect-and-discard strategy. Furthermore, just as some gastroenterologists in the USA receive income by employing anesthesiologists, some also receive income from owning pathology services. These physicians have a financial disincentive to perform resect and discard. Compensation schemes, like bundled payment, could incentivize resect and discard, but have thus far rarely been used.

A fourth issue is patient acceptance. Patients consider pathology as a final answer. Who does not recall a patient being told “we won’t know until the biopsy gets back”? When the resect-and-discard concept was explained to them, some patients were willing to go along and others had no interest [13]. This suggests implementation could require vetting with each patient, which would be time-consuming and expensive.

Box 1 lists steps that could help make resect and discard a reality. A big picture approach to colorectal cancer prevention by colonoscopy would help. What matters most is high level detection and effective polypectomy. The surveillance intervals selected for patients with low risk adenomas are less important. Second, we should accept that cancer risk in diminutive lesions is negligible. This acceptance is the essential foundation of the resect-and-discard strategy. Systematic photography of diminutive lesions would support that endoscopists had made correct decisions. Finally, recommendations from professional endoscopy societies and local institutional policies should change from “you can do resect and discard” to “you should do resect and discard.” When resect and discard is best practice, there will be less associated medicolegal risk.

In summary, the LBRD strategy is a potentially useful management approach, though it may work better in countries that either do not survey low risk adenomas or survey at 10 years only. In the USA, we need to know how well it stratifies patients with one or two low risk adenomas into 7 vs. 10 years, and those with three or four low risk adenomas into 3 vs. 5 years. An important driver of change would be policies that eliminate the perceived medicolegal risk of throwing tissue away, preferably with a financial incentive for implementation.

Publication History

Article published online:
24 September 2021

• References

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