Metachronous Advanced Neoplasia Research Articles

Serrated Polyps in Inflammatory Bowel Disease Indicate a Similar Risk of Metachronous Colorectal Neoplasia as in the General Population.

The risk of metachronous advanced neoplasia after diagnosing serrated polyps in patients with IBD is poorly understood. A retrospective multicenter cohort study was conducted between 2010 and 2019 at three tertiary centers in Montreal, Canada. From pathology databases, we identified 1587 consecutive patients with serrated polyps (sessile serrated lesion, traditional serrated adenoma, or serrated epithelial change). We included patients aged 45-74 and excluded patients with polyposis, colorectal cancer, or no follow-up. The primary outcome was the risk of metachronous advanced neoplasia (advanced adenoma, advanced serrated lesion, or colorectal cancer) after index serrated polyp, comparing patients with and without IBD. 477 patients with serrated polyps were eligible (mean age 61years): 37 with IBD, totaling 45 serrated polyps and 440 without IBD, totaling 586 serrated polyps. The median follow-up was 3.4years. There was no difference in metachronous advanced neoplasia (HR 0.77, 95% CI 0.32-1.84), metachronous advanced adenoma (HR 0.54, 95% CI 0.11-2.67), and metachronous advanced serrated lesion (HR 0.76, 95% CI 0.26-2.18) risk. When comparing serrated polyps in mucosa involved or uninvolved with IBD, both groups had similar intervals from IBD to serrated polyp diagnosis (p > 0.05), maximal therapies (p > 0.05), mucosal inflammation, inflammatory markers, and fecal calprotectin (p > 0.05). The risk of metachronous advanced neoplasia after serrated polyp detection was similar in patients with and without IBD. Serrated polyps in IBD occurred independently of inflammation. This helps inform surveillance intervals for patients with IBD diagnosed with serrated polyps.

A152 THE RISK OF UNFAVORABLE HISTOLOGIC FEATURES, LYMPH NODE METASTASIS AND METACHRONOUS ADVANCED NEOPLASIA IN PATIENTS WITH COLORECTAL INTRAMUCOSAL CARCINOMA

Abstract Background Very few studies have described the risk of unfavorable histologic features (UHFs), lymph node involvement (LNI), distant metastasis (DM) and metachronous advanced neoplasia (MAN) after the detection of colorectal intramucosal carcinoma (IMC). Aims This study aimed to determine the risk of UHFs, LNI, DM and MAN in patients with IMC, compared to high-grade dysplasia (HGD) or T1 colorectal cancer (CRC). Methods A retrospective cohort study was conducted. Through a pathology database search, we identified all consecutive patients with HGD (epithelial) (n=908) or either IMC (lamina propria or muscularis mucosa) or T1 CRC (submucosa) (n=496) diagnosed between 2010 and 2019 at the University of Montreal Hospital Center. We excluded patients with age ampersand:003C40 or ampersand:003E90, IBD, hereditary CRC or post-neoadjuvant therapy. Primary outcome was the risk of UHF, LNI and DM in IMC vs T1. Secondary outcome was the risk of MAN (metachronous advanced adenoma or advanced serrated lesion or CRC) in the IMC group, compared to HGD and T1. Files were reviewed for demographics and index and follow-up findings. The metachronous analysis excluded follow-ups ampersand:003C6 months, no follow-up or previous CRC. Follow-up continued until MAN or last colonoscopy within 10 y. Variables were compared between groups using ANOVA, chi-squared tests or Kruskal-Wallis tests, followed by post-hoc tests. We performed multivariate Cox regressions, adjusting for age, sex, family history of CRC, main lesion location, villous histology, adenomas ≥10 mm, and number of adenomas. Results The primary cohort included 90 patients with IMC (mean age 69.4 y., 44.4% female) and 207 with T1 CRC (mean age 69.8 y., 43.5% female), as well as 797 with HGD. The rates of lymphatic invasion, vascular invasion, intermediate differentiation/grade and mucinous histology were 2/90, 1/90, 7/90 and 4/90 in the IMC group compared to respectively 30/207 (2.2% vs 14.5%, pampersand:003C0.01), 15/207 (1.1% vs 7.2%, p=0.06), 68/207 (7.7% vs 32.9%, pampersand:003C0.01) and 15/207 in the T1 group (4.4% vs 7.2%, p=0.52). No other UHFs were present. No patients with IMC had LNI or DM. In the metachronous outcomes analysis, 464 patients were eligible (mean age 67.1 y., 42.2% female, median follow-up 3.0 y.): 274 with HGD, 58 with IMC and 132 with T1 CRC. Compared to HGD, patients with IMC had a lower likelihood of MAN (HR 0.46, 0.22-0.96), and T1 CRC had a similar likelihood of MAN (HR 0.65, 0.41-1.02). Compared to IMC, T1 CRC had a similar likelihood of MAN (HR 1.39, 0.63-3.09). Conclusions Patients with colorectal IMC have a small risk of UHFs, but LNI and DM were not identified in this cohort study and have not been reported. Patients with IMC and T1 CRC do not have an increased risk of MAN compared to patients with HGD. Funding Agencies None

A141 RISK OF TOTAL METACHRONOUS ADVANCED NEOPLASIA AFTER DETECTION OF PROXIMAL HYPERPLASTIC POLYPS, ADENOMAS, AND THEIR COMBINATION

Abstract Background Recent research findings have identified an association between proximal sessile serrated lesions (SSL) and a greater risk of advanced metachronous neoplasia, without significant impact of distal SSL. Aims The principal aim of this study was to assess the risk of total metachronous advanced neoplasia (T-MAN) at the follow-up (fu) colonoscopy after detection of proximal hyperplastic polyps (HP), adenomas and their combination at the initial colonoscopy. Methods Medical records for patients aged 45 to 74 who underwent colonoscopies in both 2014 and 2015 were reviewed. The primary outcome was the presence of T-MAN (comprising advanced adenomas or high-risk SL) during the follow-up colonoscopy depending on the presence of proximal HP, adenoma, or their combination at index colonoscopy. Secondary outcomes included assessing the risk of T-MAN at follow-up depending on index findings characteristics. Results 2014 patients were screened and 764 were included in the final analysis (44.1% male vs 55.9% female; mean age, 63y; median follow-up, 3.46 years). Patients with both proximal hyperplastic polyps and colonic adenomas during their initial colonoscopy had a significantly higher risk of developing T-MAN than patients with a combination of adenomas and distal HP or with only adenomas at index colonoscopy (30.5% vs 19%) [Hazard-ratio (HR)=1.95 (95% confidence interval (CI)1.3-2.9)]. A combination of proximal hyperplastic polyps and colonic adenomas is associated with a higher risk of T-MAN during follow-up than proximal HP alone (30.5% vs 13.9%) [HR=3.4 (95% CI 1.3-8.7)]. No statistically significant evidence was found to identify an increased risk of developing T-MAN at follow-up in patients presenting adenomas alone vs those with only proximal HP (19.1% vs 13.9%) [HR=1.9 (95% CI 0.75-4.7)]. Conclusions Patients with proximal hyperplastic polyps have an increased risk of presenting a T-MAN at the follow-up colonoscopy. Presenting a combination of hyperplastic polyps and adenomas indicates a higher risk of developing T-MAN than presenting an HP or adenoma alone. Funding Agencies Daniel von Renteln is supported by a "Fonds de Recherche du Québec Santé" career development award. He has also received research funding from ERBE Elektromedizin GmbH, Ventage, Pendopharm, Fujifilm and Pentax, and has received consultant or speaker fees from Boston Scientific Inc., ERBE Elektromedizin GmbH, and Pendopharm. Roupen Djinbachian is supported by a “Fonds de Recherche du Québec Santé/Ministère de la Santé et des Services Sociaux” clinical research award. The remaining authors declare that they have no conflict of interest.

The diagnostic yield of colonoscopic surveillance following resection of early age onset colorectal cancer.

The primary benefit of post-colorectal cancer (CRC) colonoscopic surveillance is to detect and remove premalignant lesions to prevent metachronous CRC. Current guidelines for long-term colonoscopic surveillance post early age onset CRC (EOCRC) resection are based on limited evidence. The aims of this study were to assess the diagnostic yield of colonoscopic surveillance post-EOCRC resection and identify molecular and clinicopathological risk factors associated with advanced neoplasia. A retrospective cohort study of prospectively collected data was conducted at St Mark's hospital, London, United Kingdom, for patients diagnosed with EOCRC who underwent at least one episode of post-CRC colonoscopic surveillance between 1978 and 2022. We collected clinicopathological data including tumour molecular status and neoplasia detection rates. In total, 908 colonoscopic surveillance procedures were performed in 195 patients over 2581.3 person-years of follow-up. The diagnostic yields of metachronous CRC, advanced adenomas and non-advanced adenomas were 1.76%, 3.41% and 22.69% respectively. Sixteen patients (8.21%) developed metachronous CRC, and the majority (87.5%) were detected more than 3years post index EOCRC diagnosis. Detection of advanced neoplasia was significantly higher in EOCRC patients with Lynch syndrome (26.15%) compared with those in whom Lynch syndrome was excluded (13.13%) (OR, 2.343; 95% CI, 1.014-5.256; p=0.0349). During colonoscopic surveillance post-EOCRC resection, the long-term risk of developing metachronous advanced neoplasia remains high in the context of Lynch syndrome, but this trend is not as clearly evident when Lynch syndrome has been excluded.

Risk factors for metachronous colorectal cancer and advanced neoplasia following primary colorectal cancer: a systematic review and meta-analysis

BackgroundIdentifying risk factors for metachronous colorectal cancer (CRC) and metachronous advanced neoplasia could be useful for guiding surveillance. We conducted a systematic review and meta-analysis to investigate risk factors for metachronous CRC and advanced neoplasia.MethodsSearches were conducted in MEDLINE, Embase, Web of Science and Cochrane Central Registry of Controlled Trials for articles (searching period: 1945 to Feburary, 2021) that reported the results of an association between any factor and metachronous advanced neoplasia or metachronous CRC. There were no restrictions on the publication date or language. Random effects models were fitted to estimate the combined association between the risk factors and metachronous CRC or advanced neoplasia. The Risk of Bias In Non-Randomised Studies of Interventions tool (ROBINS-I) was used to assess the risk of bias of included studies.ResultsIn total, 22 observational studies with 625,208 participants were included in the systematic review and meta-analysis. Of these, 13 studies investigated risk factors for metachronous CRC and 9 for advanced neoplasia. The risks of metachronous CRC or advanced neoplasia were higher if the first CRC was diagnosed in the presence of a synchronous advanced lesion (pooled risk ratio (RR) from 3 studies: 3.61, 95% confidence interval (CI): 1.44–9.05; and pooled RR from 8 studies: 2.77, 95% CI: 2.23–3.43, respectively). The risk of metachronous CRC was lower, but the risk of metachronous advanced neoplasia was higher if the first CRC was distal (compared with proximal) (pooled RR from 3 studies: 0.48, 95% CI: 0.23–0.98; and pooled RR from 2 studies: 2.99, 95% CI: 1.60–5.58 respectively). The risk of metachronous advanced neoplasia increased with age (pooled RR from 3 studies: 1.07 per year of age, 95% CI: 1.03–1.11). There was no evidence that any lifestyle risk factors studied were associated with the risk of metachronous CRC or advanced neoplasia.ConclusionsThe identified risk factors for metachronous CRC and advanced neoplasia might be useful to tailor the existing surveillance guidelines after the first CRC. There were potential limitations due to possible misclassification of the outcome, confounding and risk of bias, and the findings cannot be generalised to high-risk genetic syndrome cases.

Strategy for post-polypectomy colonoscopy surveillance: focus on the revised Korean guidelines

Background: The risk of metachronous advanced neoplasia is linked to the presence of polyps on initial colonoscopy. Consequently, it is crucial to establish an appropriate colonoscopy surveillance period post-polypectomy.Current Concepts: The US Multi-Society Task Force, the European Society of Gastrointestinal Endoscopy, and the British Society of Gastroenterology revised their respective foreign guidelines in the 2020s. In Korea, a revised edition of post-polypectomy colonoscopic surveillance was announced in 2022, with the following risk factors: (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 lesions containing any grade of dysplasia; (7) serrated polyps of at least 10 mm in size; and (8) 3 to 5 (or more) sessile serrated lesions. In these guidelines, suitable surveillance periods are suggested for each risk factor.Discussion and Conclusion: The evidence supporting the best practices for post-polypectomy colonoscopy surveillance has strengthened, helping to support both close follow-up for some populations and less intense follow-up for others.

S1171 Risk of Metachronous Advanced Neoplasia in Patients With Serrated Lesions and Inflammatory Bowel Disease

S1171 Risk of Metachronous Advanced Neoplasia in Patients With Serrated Lesions and Inflammatory Bowel Disease

Endoscopic Removal of Premalignant Lesions Reduces Long-Term Colorectal Cancer Risk: Results From the Japan Polyp Study

To date, no regional evidence of long-term colorectal cancer (CRC) risk reduction after endoscopic premalignant lesion removal has been established. We aimed to analyze this over a long-term follow-up evaluation. This was a prospective cohort study of participants from the Japan Polyp Study conducted at 11 Japanese institutions. Participants underwent scheduled follow-up colonoscopies after a 2-round baseline colonoscopy process. The primary outcome was CRC incidence after randomization. The observed/expected ratio of CRC was calculated using data from the population-based Osaka Cancer Registry. Secondary outcomes were the incidence and characteristics of advanced neoplasia (AN). A total of 1895 participants were analyzed. The mean number of follow-up colonoscopies and the median follow-up period were 2.8 years (range, 1-15 y) and 6.1 years (range, 0.8-11.9 y; 11,559.5 person-years), respectively. Overall, 4 patients (all males) developed CRCs during the study period. The observed/expected ratios for CRC in all participants, males, and females, were as follows: 0.14 (86% reduction), 0.18, and 0, respectively, and 77 ANs were detected in 71 patients (6.1 per 1000 person-years). Of the 77 ANs detected, 31 lesions (40.3%) were laterally spreading tumors, nongranular type. Nonpolypoid colorectal neoplasms (NP-CRNs), including flat (<10 mm), depressed, and laterally spreading, accounted for 59.7% of all detected ANs. Furthermore, 2 of the 4 CRCs corresponded to T1 NP-CRNs. Endoscopic removal of premalignant lesions, including NP-CRNs, effectively reduced CRC risk. More than half of metachronous ANs removed by surveillance colonoscopy were NP-CRNs. The Japan Polyp Study: University Hospital Medical Information Network Clinical Trial Registry: University Hospital Medical Information Network Clinical Trial Registry, C000000058; cohort study: UMIN000040731.

Impact of Clinical and Endoscopic Features on the Development of Metachronous Colorectal Advanced Serrated Lesions

High-risk adenomas predict metachronous advanced adenomatous neoplasia. Limited data exist on predictors of metachronous advanced serrated lesions (mASLs). We analyzed clinical and endoscopic predictors of mASLs. In this retrospective cohort study, adults with >1 outpatient colonoscopy between 2008 and 2019 at a tertiary center were included. Serrated lesions (SLs) included sessile SLs (SSLs), traditional serrated adenomas (TSAs), and hyperplastic polyps (HPs). Patient and endoscopic characteristics were obtained using electronic medical records. Five-year cumulative incidence of mASL (HP ≥10 mm, SSL ≥10 mm or with dysplasia, any TSA) and factors associated with mASL were evaluated using Kaplan-Meier estimates and Cox proportional hazards models. A total of 4990 patients were included and 45.4% were women. Mean age was 60.9 ± 9.2 years and median follow-up time was 3.7 years. Female sex and active smoking were associated with mASL. Endoscopically, any SSL and TSA were associated with mASL. The 5-year cumulative incidence for mASL was 26% (95% confidence interval [CI], 18%-32%) for SSL ≥10 mm, 17% (95% CI, 3.5%-29%) for HP ≥10 mm, 21% (95% CI, 0%-42%) for 3-4 SSLs <10 mm, 18% (95% CI, 0%-38%) for TSA, and 27% (95% CI, 3.6%-45%) for SSL with low-grade dysplasia. Baseline synchronous nonadvanced SL and nonadvanced adenoma were not associated with mASL. Our data support current recommendations for a 3-year surveillance interval in patients with baseline SSL ≥10 mm, SSL with dysplasia, and TSA. A 3-year interval may be more appropriate than 3-5 years for patients with baseline HP ≥10 mm or 3-4 SSLs <10 mm. Patients with synchronous nonadvanced SLs and adenomas do not appear to be at increased risk of mASL.

Frequency of endoscopic photodocumentation of large colorectal polyps

Colonoscopy quality impacts colorectal cancer (CRC) incidence and mortality. The US Multi-Society Task Force on CRC strongly recommends photodocumentation (PD) of large polyps ≥10 mm (LP) pre-resection and suggests PD post-resection to enhance the quality of colonoscopy. No studies have assessed the frequency of PD of LP. We evaluated frequency of and factors associated with PD of LP. Reports from endoscopists performing ≥50 colonoscopies with LP resection between 2016-2021 were reviewed. The frequency of PD of LP pre- and post-resection and factors associated with PD were collected. A composite score of 2 quality metrics (PD of completeness of exam and bowel preparation quality) was created. Endoscopists were divided into 2 tiers based upon the frequency of the score on all included exams: Tier 1: ≥95% of exams; Tier 2: <95% of exams. Univariate and multivariate analysis was used to assess factors associated with PD. 1322 colonoscopies, 1693 LPs, and 25 endoscopists were included. PD of LPs occurred in 1392 (82%) pre-resection and 878 (52%) post-resection. Factors associated with pre-resection PD include endoscopist subspecialty (colorectal surgery vs gastroenterology, (Odds Ratio (OR) = 0.12, 95% Confidence Interval (CI)= 0.04-0.42); >1 LP on exam (2 vs. 1 LP: OR=0.41, 95% CI=0.27-0.61 and ≥3 vs 1 LP: OR=0.41, 95% CI=0.24-0.70); and longer withdrawal time (OR=1.02, 95% CI=1.01-1.04). We provide the first data on PD of LP pre-resection and post-resection which can inform future benchmarking in this area. The implications of PD on metachronous advanced neoplasia need to be studied.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 Revision

The risk of developing metachronous advanced neoplasia is associated with the presence of polyps in index colonoscopy. Therefore, it is essential to establish the optimal colonoscopy surveillance period following polypectomy. In the 2020s, international guidelines published by the US Multi-Society Task Force, European Society of Gastrointestinal Endoscopy, and British Society of Gastroenterology were revised. In 2022, the Korean postpolypectomy colonoscopic surveillance guidelines were revised to recommend surveillance for adenoma size ≥ 10 mm, ≥ 3 adenomas, tubulovillous or villous adenoma, adenoma with high-grade dysplasia, traditional serrated adenoma, sessile serrated lesion (SSL) with dysplasia, serrated polyp with size ≥ 10 mm, and ≥ 3 SSLs.

Proteomic Profiling of Colorectal Adenomas Identifies a Predictive Risk Signature for Development of Metachronous Advanced Colorectal Neoplasia

Colonic adenomatous polyps, or adenomas, are frequent precancerous lesions and the origin of most cases of colorectal adenocarcinoma. However, we know from epidemiologic studies that although most colorectal cancers (CRCs) originate from adenomas, only a small fraction of adenomas (3%-5%) ever progress to cancer. At present, there are no molecular markers to guide follow-up surveillance programs. We profiled, by mass spectrometry-based proteomics combined with machine learning analysis, a selected cohort of formalin-fixed, paraffin-embedded high-grade (HG) adenomas with long clinical follow-up, collected as part of the Danish national screening program. We grouped subjects in the cohort according to their subsequent history of findings: a nonmetachronous advanced neoplasia group (G0), with no new HG adenomas or CRCs up to 10 years after polypectomy, and a metachronous advanced neoplasia group (G1) where individuals developed a new HG adenoma or CRC within 5 years of diagnosis. We generated a proteome dataset from 98 selected HG adenoma samples, including 20 technical replicates, of which 45 samples belonged to the nonmetachronous advanced neoplasia group and 53 to the metachronous advanced neoplasia group. The clear distinction of these 2 groups seen in a Uniform Manifold Approximation and Projection plot indicated that the information contained within the abundance of the ∼5000 proteins was sufficient to predict the future occurrence of HG adenomas or development of CRC. We performed an in-depth analysis of quantitative proteomic data from 98 resected adenoma samples using various novel algorithms and statistical packages and found that their proteome can predict development of metachronous advanced lesions and progression several years in advance.

Risk of total metachronous advanced neoplasia at surveillance colonoscopy after detection of serrated lesions: a matched case-cohort study.

BACKGROUND : Serrated lesions are potential colorectal cancer precursors. This study evaluated the presence of total metachronous advanced neoplasia (T-MAN) at follow-up in patients with index serrated lesions compared with a matched cohort without serrated lesions. METHODS : Patients aged 45-74 years with serrated lesions were matched 2:1 by sex, age, synchronous polyps, and timing of index colonoscopy, to patients without serrated lesions. The primary outcome was T-MAN (advanced adenoma or high-risk serrated lesion) at follow-up. Secondary outcomes included presence of T-MAN stratified by synchronous polyps and serrated lesion characteristics. RESULTS : 1425 patients were included (475 patients, 642 serrated lesions; 950 controls; median follow-up 2.9 versus 3.6 years). Patients with serrated lesions had greater risk of T-MAN than those without (hazard ratio [HR] 6.1, 95 %CI 3.9-9.6). Patients with serrated lesions and high-risk adenoma (HRA) had higher risk of T-MAN than those with HRA alone (HR 2.6, 95 %CI 1.4-4.7); similarly, patients with serrated lesions plus low-risk adenoma (LRA) had higher risk than those with LRA alone (HR 7.0, 95 %CI 2.8-18.4), as did patients with serrated lesions without adenoma compared with no adenoma (HR 14.9, 95 %CI 6.5-34.0). Presence of proximal sessile serrated lesion (SSL; HR 9.3, 95 %CI 5.4-15.9), large SSL (HR 17.8, 95 %CI 7.4-43.3), and proximal large SSL (HR 25.0, 95 %CI 8.8-71.3), but not distal SSL, were associated with greater risk for T-MAN. CONCLUSION : Patients with serrated lesions had higher risk for T-MAN regardless of synchronous adenomas. Patients with serrated lesions and HRA, and those with large or proximal SSLs, were at greatest risk.

A232 RISK OF TOTAL METACHRONOUS ADVANCED NEOPLASIA AT SURVEILLANCE COLONOSCOPY AFTER DETECTION OF SERRATED LESIONS: A MATCHED COHORT STUDY

Abstract Background Serrated lesions (SLs), including sessile serrated lesions (SSL) and traditional serrated adenomas (TSA) have become subject of increased interest for their role as CRC precursors. Purpose Study aim was to evaluate the risk to develop total metachronous advanced neoplasia (T-MAN) at follow-up in patients with index SL compared to a matched cohort without SL. Method Patients 45-74y with SLs were identified through pathology database search. SL patients were matched 2:1 by sex; age; synchronous polyps (high-risk adenoma [HRA], low-risk adenoma [LRA], no-adenoma); timing of index, to patients without SL. Primary outcome was risk of T-MAN (advanced adenoma or high-risk SL) at follow-up. Secondary outcomes included risk of T-MAN stratified by synchronous polyps and SL characteristics. Result(s) 1425 patients were included (475 patients, 642 SLs; 950 controls (mean follow-up 2.9 vs 3.9y). The SL group had greater risk of T-MAN compared to the non-SL group [Hazard-ratio (HR)=6.12 (95%confidence-interval (CI)3.91-9.58)]. Patients with SL+HRA had higher risk of T-MAN compared to HRA alone [HR=2.62 (95%CI 1.45-4.71)], as well as patients with SL+LRA compared to LRA alone [HR=7.03 (95%CI 2.78-18.44)], and SL without adenoma compared to no-adenoma [HR=14.87 (95%CI 6.51-33.95)]. Presence of proximal SSL (HR=9.30), large SSL (HR=17.87) and proximal large SSL (HR=24.99), but not distal SSL, was associated with greater risk for T-MAN. Conclusion(s) Patients with SLs are at greater risk for developing T-MAN regardless of synchronous adenomas. Patients with SL and HRA, and those with large or proximal SSLs appear to be at greatest risk for T-MAN. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; ACG Disclosure of Interest R. Djinbachian Grant / Research support from: Grant from the American College of Gastroenterology for the conduction of this project, M.-L. Lafontaine: None Declared, J. Anderson: None Declared, H. Pohl: None Declared, T. Dufault: None Declared, M. Boivin: None Declared, M. Bouin: None Declared, D. von Renteln Grant / Research support from: Daniel von Renteln is supported by a “Fonds de Recherche du Québec Santé” (FRQS) career development award and has received research funding from ERBE, Ventage, Pendopharm, Fujifilm, and Pentax., Consultant of: Boston Scientific and Pendopharm,

A159 RISK OF TOTAL METACHRONOUS ADVANCED NEOPLASIA IN PATIENTS WITH SERRATED LESIONS AND INFLAMMATORY BOWEL DISEASE

Abstract Background The risk of total metachronous advanced neoplasia (TMAN) in patients with serrated lesions (SL) and IBD is unknown. It is also unclear whether colonic inflammation in IBD contributes to serrated neoplasia. Purpose Study aim was to compare the risk of TMAN at surveillance colonoscopies in patients with SL and IBD to patients with SL without IBD. We also sought to compare IBD severity in patients with IBD and SL in a colonic area involved with IBD (SL-IA) to patients with IBD and SL in an uninvolved area (SL-UA). Method A cohort study was conducted. Through pathology database search, we identified 2428 patients with endoscopically resected SL, defined as sessile serrated lesion (SSL), traditional serrated adenoma (TSA) or IBD and serrated epithelial change (SEC), between 2010 and 2019 at the University of Montreal Hospital Center. We included patients aged 45-75 without polyposis syndromes and excluded patients with a history of CRC, first surveillance &amp;lt;12 months after complete index, sigmoidoscopy at index, or no follow-up. Patient files were reviewed for demographic data, IBD severity, and findings at index and follow-up. Follow-up was continued until TMAN or last colonoscopy within 10 years. Primary outcome was the risk of TMAN (defined as advanced adenoma (AA), advanced serrated lesion (ASL) or CRC) in a surveillance colonoscopy within 10 years from index. Secondary outcomes were the risk of metachronous AA and ASL, and IBD severity in SL-IA and SL-UA. Continuous and categorical variables were compared using the student t, Pearson’s chi-squared, or Mann-Whitney tests. We performed univariate and multivariate Cox regressions, with hazard ratios (HR) and 95% confidence intervals. Result(s) In the metachronous outcomes analysis, 440 patients with SL (mean age 61.8 y., 51.6% male, 424 SSL, 16 TSA) were eligible, and 37 with SL and IBD were eligible (mean age 60.9 y., 54.1% male, 30 SSL, 6 SEC, 1 TSA). Compared to patients without IBD, IBD patients were less likely to have synchronous adenomas (16.2% vs 41.6%, p&amp;lt;0.05), had less SLs ≥10 mm (24.3% vs 46.8%, p&amp;lt;0.05), and had a similar risk of metachronous TMAN (HR=0.92 [0.44–1.90]), AA (HR=0.53 [0.13–2.12]) and ASL (HR=1.03 [0.44–2.41]). In the comparison of SL-UA and SL-IA, 56 patients with IBD were eligible, with 21 having SL-UA (mean age 62.0 y., 42.9% male, 19 SSL, 1 TSA, 1 SEC) and 35 having SL-IA (mean age 60.8 y., 62.9% male, 27 SSL, 1 TSA and 8 SEC). Both groups had similar time intervals between IBD diagnosis and SL diagnosis (p&amp;gt;0.05), and similar maximal therapeutic maintenance steps (p&amp;gt;0.05), as well as Mayo/SES-CD scores, serum C-reactive protein, hemoglobin, and albumin, and fecal calprotectin values at index and last colonoscopy (p&amp;gt;0.05). Conclusion(s) Patients with SL and IBD are not at higher risk of total metachronous advanced neoplasia than patients with SL and no IBD. SLs in IBD should be considered sporadic and undergo endoscopic resection and follow-up similar to non-IBD patients. Please acknowledge all funding agencies by checking the applicable boxes below CIHR, Other Please indicate your source of funding; Fonds de Recherche du Québec en Santé Disclosure of Interest None Declared

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.

Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy

Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors. We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.S. Department of Veterans Affairs (VA). Clinical factors, polyp findings, and baseline colonoscopist ADR were considered for the model. Model performance (sensitivity, specificity, and area under the curve) for identifying individuals with MAN was compared with 2020 U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) surveillance recommendations. A total of 30,897 individuals were randomly assigned 2:1 into independent model training and validation sets. Increasing age, male sex, diabetes, current smoking, adenoma number, polyp location, adenoma ≥10 mm or with tubulovillous/villous features, and decreasing colonoscopist ADR were independently associated with MAN. A range of 1.48- to 1.66-fold increased risk for MAN was observed for ADR in the lowest 3 quintiles (ADR <19.7%-39.3%) vs the highest quintile (ADR >47.0%). When the final model selected based on the training set was applied to the validation set, improved sensitivity and specificity over 2020 USMSTF risk stratification were achieved (P= .001), with an area under the curve of 0.62 (95% confidence interval, 0.60-0.64). Colonoscopist ADR is associated with MAN. Combining clinical factors and ADR for risk stratification has potential to improve postpolypectomy risk stratification. Improving ADR is likely to improve postpolypectomy outcomes.

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.