Postpolypectomy Surveillance Research Articles

Colorectal cancer and advanced adenoma incidence during post-polypectomy surveillance: a national cohort study in the English Bowel Cancer Screening Programme.

Improved colonoscopy quality has led to debate about whether all post-polypectomy surveillance is justified. We evaluated surveillance within the English Bowel Cancer Screening Programme (BCSP) to determine the yield of surveillance and identify predictive factors for surveillance outcome. We performed a retrospective cohort study of individuals undergoing post-polypectomy surveillance between July 2006 and January 2017. BCSP records were linked to the National Cancer Registration Database to identify interval-type post-colonoscopy colorectal cancers (CRCs). Advanced adenoma and CRC at surveillance were documented. CRC incidence was compared with the general population using standardized incidence ratios (SIRs). Predictors of advanced adenomas at first surveillance (S1), and CRC during follow-up, were identified. 44 151 individuals (23 078 intermediate risk; 21 073 high risk) underwent 64 544 surveillance episodes. Advanced adenoma and CRC yields were, respectively, 10.0 % and 0.5 % at S1, 8.5 % and 0.4 % at S2, and 10.8 % and 0.4 % at S3. S1 yield was lowest in those with one index adenoma ≥ 10 mm (advanced adenoma 6.1 %; CRC 0.3 %). The SIR was 0.76 (95 %CI 0.66-0.88), accounted for by the intermediate risk group (intermediate risk SIR 0.61, 95 %CI 0.49-0.75; high risk SIR 0.95, 95 %CI 0.79-1.15). Adenoma multiplicity, presence of a large nonpedunculated adenoma, and greater villous component were associated with advanced adenoma at S1. Older age and multiplicity were significantly associated with CRC risk. This large, national analysis found low levels of CRC in those undergoing surveillance and low advanced adenoma yield in most subgroups. Less intensive surveillance in some subgroups is warranted, and surveillance may be avoided in those with a single large adenoma.

Through the Looking Glass: Surveillance Following Colonoscopic Polypectomy of Malignant Polyps.

Introduction Colonoscopic polypectomy is a well-established screening and surveillance modality for malignant colorectal polyps. Following the detection of a malignant polyp, patients are either put on endoscopic surveillance or planned for a surgical procedure. We studied the outcome of colonoscopic excision of malignant polyps and their recurrence rates. Methods We performed a retrospective analysis over a period of five years (2015-2019) of patients who underwent colonoscopy and resection of malignant polyps. Size of polyp, follow-up with tumour markers, CT scan, and biopsy were considered individually for pedunculate and sessile polyps. We analysed the percentage of patients who underwent surgical resection, the percentage of patients who were managed conservatively, and the percentage of recurrence post-excision of malignant polyps. Results A total of 44 patients were included in the study. Of the 44 malignant polyps, most were present in the sigmoid colon at 43% (n=19), with the rectum containing 41% (n=18). The ascending colon accounted for 4.5% (n=2), transverse colonic polyps were 7% (n=3), and the descending colon polyps were 4.5% (n=2). Pedunculated polyps made up 55% (n=24). These were Level 1-3 based on Haggits classification; 14 were Haggits Level 1, eight were Haggits Level 2, and two were Haggits Level 3. The rest were sessile polyps making up 45% (n=20). Based on the Kikuchi classification, these were predominantly SM1 (n=12) and SM2 (n=8). Out of 44 cases, 11% (n=5) underwent surgical resection on follow-up in the form of bowel resection. This included three right hemicolectomies, one sigmoid colectomy, and one low anterior resection. Seven per cent (n=3) underwent endoscopic resection as trans-anal endoscopic mucosal resection (TEMS) and 82% (n=36) of the remaining cases were managed with regular follow-up and surveillance. Conclusions Colonoscopic polypectomy offers excellent benefits in detecting colorectal cancer and treating pre-malignant polyps. Colonoscopic polypectomy provides excellent benefits in colorectal cancer (CRC) detection and treatment of malignant polyps. However, it remains to be seen if post-polypectomy surveillance for low-risk polyp cancers would require a change in surveillance.

Adherence to Post-polypectomy Surveillance Guidelines at a Large District General Hospital.

Introduction In 2020, the British Society of Gastroenterologists(BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI), and Public Health England (PHE) published joint guidelines regardingpost-polypectomy surveillance. This study aimed to establish clinician adherence at the Royal Devon University Healthcare NHS Foundation Trust to the 2020 guidelines compared to the now-retired 2010 guidelines. Materials and Methods Data on 152 patients treated under the 2010 guidelines and 133 patients treated under the 2020 guidelines were collected retrospectively from the hospital's colonoscopy database. Data were analysed to determine whether patients who had a colonoscopy fulfilled BSG/ACPGBI/PHE guidelines for follow-up. Costs were estimated using the price of colonoscopy in the NHS National Schedule. Results Approximately 41.4% (63/152) of patients were adherent to the 2010 guidelines while 66.2% (88/133) of patients were adherent to the 2020 guidelines. The difference in adherence rate was 24.7% (95% confidence interval 13.5% - 35.9%, p<0.0001). Nearly 37% (35/95) of patients who would have been followed up under the 2010 guidelines did not receive any follow-up as a result of the 2020 guidelines. This represents a cost saving of £36,892.28 per year in our hospital. Approximately 47% (28/60) of patients treated under the 2020 guidelines had surveillance colonoscopy planned when the guidelines recommended no follow-up. If every clinician were fully adherent to the 2020 guidelines, then a further £29,513.82 per year would have been saved. Discussion and Conclusion Following the introduction of the 2020 guidelines, adherence to polyp surveillance guidelines increased in our hospital. However, nearly half of the colonoscopies were performed unnecessarily due to non-adherence. Furthermore, our results demonstrate that the 2020 guidelines have decreased the need for follow-up.

Use of surveillance colonoscopy among individuals with removal of high-risk polyps according to the US Multi-Society Task Force recommendations.

Individuals with colorectal polypectomy are recommended to undergo surveillance colonoscopies at certain intervals to prevent subsequent colorectal cancer. Use of postpolypectomy surveillance according to the 2006 US Multi-Society Task Force (USMSTF) recommendations in an integrated health care system was investigated. Use of surveillance colonoscopies was prospectively assessed among 3691 patients with removal of high-risk polyps at a screening colonoscopy during 2007-2012 in the Mass General Brigham Colonoscopy Cohort. With the follow-up up to 2017, the compliance with, overuse, and underuse of postpolypectomy surveillance according to the 2006 USMSTF recommendations was assessed. Surveillance use according to demographic factors was also investigated. During a median follow-up of 4.4years (5thpercentile, 95thpercentile, 1.0, 9.9) 2360 (64%) patients had undergone a surveillance colonoscopy, among whom 758 (21%) were considered compliant with the USMSTF recommendations. A substantial underuse of surveillance colonoscopies of 62% was observed. Older age and lower income were associated with a higher incidence of underuse, whereas having a family history of colorectal cancer were associated with lower incidence of underuse. Overuse of surveillance colonoscopies was present in 17% of patients but showed no significant associations with demographic factors. Substantial underuse of surveillance in patients with high-risk polypswasobserved, particularly those with low income and older age. Efforts are needed to improve delivery and use of surveillance colonoscopy. The US Multi-Society Task Force recommends follow-up surveillance colonoscopy after polyp removal in the bowel, with intervals depending on the most severe findings. Adherencetosurveillancerecommendationsin a large study with up to 10years of follow-up among patients with high-risk polyps was investigated. Only 21% of patients adhered to the surveillance recommendations, whereas 62% showed delayed or no use of surveillance. Findings highlight the need for improved use of surveillance colonoscopy among patients at high risk of colorectal cancer.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Using New Hampshire Colonoscopy Registry data to assess United States and European post-polypectomy surveillance guidelines.

Our goal was to compare the updated European Society of Gastrointestinal Endoscopy (ESGE) and United States Multi-Society Task Force on Colorectal Cancer (USMSTF) high risk groups in predicting metachronous advanced neoplasia on first follow-up colonoscopy and long-term colorectal cancer (CRC). We compared advanced metachronous neoplasia risk (serrated polyps ≥ 1 cm or with dysplasia, advanced adenomas [≥ 1 cm, villous, high grade dysplasia], CRC) on first surveillance colonoscopy in patients with high risk findings according to ESGE versus USMSTF guidelines. We also compared the positive and negative predictive values (PPV, NPV) of both guidelines for metachronous neoplasia. The risk for metachronous neoplasia in our sample (n = 20 458) was higher in the high risk USMSTF (3 year) (13.6 %; 95 %CI 12.3-14.9) and ESGE groups (13.6 %; 95 %CI 12.3-15.0) compared with the lowest risk USMSTF (5.1 %; 95 %CI 4.7-5.5; P < 0.001) and ESGE categories (6.3 %; 95 %CI 6.0-6.7; P < 0.001), respectively. Adding other groups such as USMSTF 5-10-year and 3-5-year groups to the 3-year category resulted in minimal change in the PPV and NPV for metachronous advanced neoplasia. High risk ESGE (hazard ratio [HR] 3.03, 95 %CI 1.97-4.65) and USMSTF (HR 3.07, 95 %CI 2.03-4.66) designations were associated with similar long-term CRC risk (CRC per 100 000 person-years: USMSTF 3-year group 3.54, 95 %CI 2.68-4.68; ESGE high risk group: 3.43, 95 %CI 2.57-4.59). Performance characteristics for the ESGE and USMSTF recommendations are similar in predicting metachronous advanced neoplasia and long-term CRC. The addition of risk groups, such as the USMSTF 5-10-year and 3-5-year groups to the USMSTF 3-year category did not alter the PPV or NPV significantly.

An audit of compliance with the updated post-polypectomy and post-colorectal cancer resection surveillance guidelines at a District General Hospital (DGH)

Background: It is important we identify cases of premalignant polyps and stratify patients according to future colorectal cancer (CRC) risk to prevent CRC development. In 2020, the British Society of Gastroenterology (BSG) published guidelines to tailor post-polypectomy and post-CRC resection surveillance. The objective of our audit was to determine whether our department was adhering to these guidelines.

Serrated polyposis: an overview

The British Society of Gastroenterology in 2020 updated its guidelines around the management of hereditary colorectal cancer. This document includes recommendations for the management of patients with serrated polyposis in combination with updated (2019) post-polypectomy surveillance guidelines, which replaced the 2017 position statement on serrated polyps in the colon and rectum. This article is intended to serve as an introduction to serrated polyposis, current practice recommendations and the challenges associated with the diagnosis and treatment of serrated polyposis. It covers the definition of serrated polyps and serrated polyposis, the endoscopic approaches for optimising detection and the follow up care that is put in place, for both patients and their families from the perspective of a nurse endoscopist.

Linked-Color Imaging Detects More Colorectal Adenoma and Serrated Lesions: An International Randomized Controlled Trial

Effects of linked-color imaging (LCI) on colorectal lesion detection and colonoscopy quality remain controversial. This study compared the detection rates of adenoma and other precursor lesions using LCI vs white-light imaging (WLI) during screening, diagnostic, and surveillance colonoscopies. This randomized controlled trial was performed at 11 institutions in 4 Asian countries/regions. Patients with abdominal symptoms, a primary screening colonoscopy, positive fecal immunochemical test results, or undergoing postpolypectomy surveillance were recruited and randomly assigned in a 1:1 ratio to either the LCI or high-definition WLI group. The primary outcome was adenoma detection rate (ADR). Secondary outcomes were polyp detection rate, advanced ADR, sessile serrated lesion (SSL) detection rate, and the mean number of adenomas per colonoscopy. The recommended surveillance schedule distribution after trial colonoscopy was analyzed. Between November 2020 and January 2022, there were 3050 participants (LCI, n= 1527; WLI, n= 1523) recruited. The LCI group ADR was significantly higher than the WLI group ADR using intention-to-treat (58.7% vs 46.7%; P < .01) and per-protocol analyses (59.6% vs 46.4%; P < .01). The LCI group polyp detection rates (68.6% vs 59.5%; P < .01), SSL detection rates (4.8% vs 2.8%; P < .01), and adenomas per colonoscopy (1.48 vs 1.02; P < .01) also were significantly higher. However, the advanced ADR was not significantly different (13.2% vs 11.0%; P= .06). Significantly more patients in the LCI group had shorter recommended surveillance schedules than the WLI group (P < .01). Compared with WLI, LCI improved adenoma and other polyp detection rates, including SSLs, resulting in alteration of the recommended surveillance schedule after screening, diagnostic, and postpolypectomy surveillance colonoscopies. UMIN000042432 (https://www.umin.ac.jp/ctr/index.htm).

Comparative Performance of Artificial Intelligence Optical Diagnosis Systems for Leaving in Situ Colorectal Polyps

Comparative Performance of Artificial Intelligence Optical Diagnosis Systems for Leaving in Situ Colorectal Polyps

Performance of a novel computer-aided diagnosis system in the characterization of colorectal polyps, and its role in meeting Preservation and Incorporation of Valuable Endoscopic Innovations standards set by the American Society of Gastrointestinal Endoscopy.

There has been an increasing role of artificial intelligence (AI) in the characterization of colorectal polyps. Recently, a novel AI algorithm for the characterization of polyps was developed by NEC Corporation (Japan). The aim of our study is to perform an external validation of this algorithm. The study was a video-based evaluation of the computer-aided diagnosis (CADx) system. Patients undergoing colonoscopy were recruited to record videos of colonic polyps. The frozen polyp images extracted from these videos were used for real-time histological prediction by the endoscopists and by the CADx system, and the results were compared. A total of 115 polyp images were extracted from 66 patients. Sensitivity, negative predictive valueand accuracy for diminutive polyps on white light imaging (WLI) and image-enhanced endoscopy (IEE) when assessed by CADx was 90.9% [95% confidence interval (CI) 77.3-100] and 95.8% [95% CI 87.5-100], 80% [95% CI 44.4-97.5] and 90.9% [95% CI 58.7-99.8], 84.8% [95% CI 72.7-97] and 84.6% [95%CI 71.8-94.9], respectively, compared to 48.1% [95%CI 37.7-59.1] and 72% [95% CI 62.5-81], 37.5% [95% CI 28.8-46.8] and 55% [95% CI 44.7-65.0], 53.7% [95% CI 44.2-63.2] and 66.7% [95% CI 59.7-73.3] when assessed by endoscopists. Concordance between histology and CADx-based post-polypectomy surveillance intervals was 93.02% on WLI and 96% on IEE. AI-based optical diagnosis is promising and has the potential to be better than the performance of general endoscopists. We believe that AI can help make real-time optical diagnoses of polyps meeting the Preservation and Incorporation of Valuable endoscopic Innovations standards set by the American Society of Gastrointestinal Endoscopy.

Measuring polyp size using a virtual scale endoscope: a video tutorial with clinical case demonstration.

Accurate real-time endoscopic assessment of colorectal polyp size plays a key role for selecting adequate post-polypectomy surveillance intervals or when choosing appropriate polypectomy techniques [1]. While visual estimation is the most commonly used method of measurement, there is marked interobserver variability. Biopsy forceps and ruler snares can be used as references for polyp size estimation, but are limited by being external devices that lengthen the duration of the endoscopy and increase the procedural cost [2] [3].

Korean guidelines for postpolypectomy colonoscopic surveillance: 2022 revised edition.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for the management of advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: (1) adenoma ≥10 mm in size; (2) 3 to 5 (or more) adenomas; (3) tubulovillous or villous adenoma; (4) adenoma containing high-grade dysplasia; (5) traditional serrated adenoma; (6) sessile serrated lesion (SSL) containing any grade of dysplasia; (7) serrated polyp of at least 10 mm in size; and (8) 3 to 5 (or more) SSLs. More studies are needed to fully comprehend the patients most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 Revised Edition

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: 1) adenoma ≥10 mm in size; 2) 3-5 (or more) adenomas; 3) tubulovillous or villous adenoma; 4) adenoma containing high-grade dysplasia; 5) traditional serrated adenoma; 6) sessile serrated lesion (SSL) containing any grade of dysplasia; 7) serrated polyp of at least 10 mm in size; and 8) 3-5 (or more) SSLs. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Author commentary on Amanda J. Cross et al.

Amanda J. Cross et al. Post-polypectomy surveillance interval and advanced neoplasia detection rates: a multicenter, retrospective cohort study

Impact of the European Society of Gastrointestinal Endoscopy 2020 guidelines on the number of scheduled post-polypectomy surveillance colonoscopies: Meeting presentations: Partial results of this research were published in abstract form at ESGE Days 2020.

Background and study aims In contrast with the European Society of Gastrointestinal Endoscopy (ESGE) 2013 and the US Multi-society Task Force (USMSTF) 2020 guidelines, the ESGE 2020 guideline considers patients with three to four adenomas < 10 mm or an adenoma with villous histology as low risk. The aim of this study was to quantify the influence of the application of the new ESGE 2020 guidelines, as opposed to the ESGE 2013 and USMSTF 2020 guidelines, on the number of scheduled colonoscopies, and to describe the main causes for changes in the surveillance intervals. Patients and methods A retrospective evaluation was conducted of a prospectively maintained fecal immunochemical test (FIT)-based regional colorectal cancer screening program database. Surveillance regimens following ESGE 2020, ESGE 2013, and USMSTF 2020 guidelines were compared. Results Overall, 1284 individuals with a positive FIT and undergoing colonoscopy were consecutively included. When applying the ESGE 2020 guidelines, 10.8 % of patients changed to a “no-surveillance” group (relative reduction in colonoscopies of 82.5 %). The main reason for these changes was considering three to four adenomas as low risk. The proportion of patients from the “3-year surveillance” group who moved to the “no-surveillance” group was lower when a sessile serrated lesion (SSL) was present (ESGE 2013, 32.0% vs 16.3 %; USMSTF 2020 17.2 % vs 6.8 %). Analyzing the 41 patients with SSLs who remained unchanged in the “no-surveillance” group, only in 15 (36.6 %) the cause was the presence of an SSL. Conclusions applying the new ESGE 2020 guidelines could reduce by 11 % the proportion of individuals being offered surveillance. SLLs have not a major influence on the change of surveillance intervals.

TU2.11 Adherence to post-polypectomy surveillance guidelines in a district general hospital

Abstract Aims National guidelines instruct clinical decision making around post-polypectomy surveillance. The current polyp surveillance guidelines were jointly published by the British Society of Gastroenterologists (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE) in 2019, updating the 2010 surveillance guidelines. Adherence to polyp surveillance guidelines is historically poor, both in the UK and globally. This audit set out to establish the adherence rate of clinicians to the 2019 polyp surveillance guidelines in a district general hospital and to compare this to the adherence rate to the 2010 surveillance guidelines. Methods We aimed to collect 300 patients who had been treated under the 2010 or 2019 polyp surveillance guidelines. After exclusion criteria were applied we collected 152 and 133 patients who had respectively been treated under the 2010 and 2019 guidelines. Each patient record was analysed and it was determined by our team whether the chosen polyp surveillance was adherent to the respective guidelines or not. Results Of 152 patients treated under the 2010 guidelines, 41.4% (63) of patients were adherent. Of 133 patients treated under the 2019 guidelines, 66.2% (88) of patients were adherent. This represents a score difference of 24.7% (95% confidence interval of 13.5% to 35.9%, p&amp;lt;0.0001). Conclusions Our results show that following the introduction of the 2019 guidelines, adherence to polyp surveillance guidelines increased. Increased adherence to guidelines has significant implications for improving patient safety, financial savings and protecting endoscopy capacity.

TU2.5 Compliance of colonic polyp surveillance with British Society of Gastroenterology (BSG) and the Association of Coloproctology of Great Britain and Ireland (ACPGBI) guidelines

Abstract Introduction The guidelines for post-polypectomy and post-colorectal cancer resection have recently been changed after consensus by the British Society of Gastroenterology, the Association of Coloproctology of Great Britain and Ireland and Public Health England. The aim of our study is to evaluate the rate of compliance with the recommended guidelines following polyp removal. Methods The data was collected retrospectively by reviewing the colonoscopy database in a single centre district general hospital for all patients who underwent polypectomy during April-September 2021. We excluded patients who had prior history of colorectal malignancy. The frequency of subsequent colonoscopic surveillance were evaluated against the BSG/ACPGBI guidelines based on the clinico-histological characteristics of the removed polyps. Results There were 104 colonoscopies with polypectomies performed during April-September 2021. The patient cohort had a mean age of 65 years (range, 35–85 years), with the most common diagnosis being tubular adenoma with low grade dysplasia (n=86, 82.7%). Adherence to BSG/ACPGBI colonoscopic post-polypectomy surveillance guidelines, based on the characteristics of the colonic polyps at colonoscopy and histology, was 86.5% (n=90). There were 5 (4.8%) patients who had their surveillance endoscopy requested earlier than recommended and 8 (7.7%) patients had a surveillance colonoscopy requested but did not require any surveillance. 1 patient had colonoscopy requested later than recommended. There was no significant difference in compliance between physicians (87.5%) and surgeons (86.1%). Conclusion There is a high compliance with post-polypectomy surveillance guidelines. However more efforts and staff training are required to improve compliance even further.

Post-polypectomy surveillance: the present and the future.

An appropriate post-polypectomy surveillance program requires the effectiveness of reducing colorectal cancer and safety. In addition, the post-polypectomy surveillance program should consider the burden of limited medical resource capacity, cost-effectiveness, and patient adherence. In this sense, a risk-stratified surveillance program based on baseline colonoscopy results is ideal. Major international guidelines for post-polypectomy surveillance, such as those from the European Union and the United States, have recommended risk-stratified surveillance programs. Both guidelines have recently been updated to better differentiate between high- and low-risk individuals. In both updated guidelines, more individuals have been downgraded to lower-risk groups that require less frequent or no surveillance. Furthermore, increased attention has been paid to the surveillance of patients who undergo serrated polyp removal. Previous guidelines in Japan did not clearly outline the risk stratification in post-polypectomy surveillance. However, the new colonoscopy screening and surveillance guidelines presented by the Japan Gastroenterological Endoscopy Society include a risk-stratified post-polypectomy surveillance program. Further discussion and analysis of unresolved issues in this field, such as the optimal follow-up after the first surveillance, the upper age limit for surveillance, and the ideal method for improving adherence to surveillance guidelines, are warranted.

Artificial Intelligence Allows Leaving-In-Situ Colorectal Polyps

Artificial Intelligence (AI) could support cost-saving strategies for colonoscopy because of its accuracy in the optical diagnosis of colorectal polyps. However, AI must meet predefined criteria to be implemented in clinical settings. An approved computer-aided diagnosis (CADx) module for differentiating between adenoma and nonadenoma in unmagnified white-light colonoscopy was used in a consecutive series of colonoscopies. For each polyp, CADx output and subsequent endoscopist diagnosis with advanced imaging were matched against the histology gold standard. The primary outcome was the negative predictive value (NPV) of CADx for adenomatous histology for ≤5-mm rectosigmoid lesions. We also calculated the NPV for AI-assisted endoscopist predictions, and agreement between CADx and histology-based postpolypectomy surveillance intervals according to European and American guidelines. Overall, 544 polyps were removed in 162 patients, of which 295 (54.2%) were ≤5-mm rectosigmoid histologically verified lesions. CADx diagnosis was feasible in 291 of 295 (98.6%), and the NPV for ≤5-mm rectosigmoid lesions was 97.6% (95% CI, 94.1%-99.1%). There were 242 of 295 (82%) lesions that were amenable for a leave-in-situ strategy. Based on CADx output, 212 of 544 (39%) would be amenable to a resect-and-discard strategy, resulting in a 95.6% (95% CI, 90.8%-98.0%) and 95.9% (95% CI, 89.8%-98.4%) agreement between CADx- and histology-based surveillance intervals according to European and American guidelines, respectively. A similar NPV (97.6%; 95% CI, 94.8%-99.1%) for ≤5-mm rectosigmoids was achieved by AI-assisted endoscopists assessing polyps with electronic chromoendoscopy, with a CADx-concordant diagnosis in 97.2% of cases. In this study, CADx without advanced imaging exceeded the benchmarks required for optical diagnosis of colorectal polyps. CADx could help implement cost-saving strategies in colonoscopy by reducing the burden of polypectomy and/or pathology. gov registration number: NCT04884581.