Post Endoscopy Barrett’s Neoplasia (PEBN) After A Negative Index Endoscopy: A Systematic Review & Proposal For Definitions and Performance Measures in Endoscopy

Background and aims: A high rate of neoplasia (high grade dysplasia; HGD and esophageal adenocarcinoma; EAC) has been reported in Barrett’s Esophagus at index endoscopy but precise rates of post endoscopy Barrett’s neoplasia (PEBN) are unknown. Methods: Systematic review and meta-analysis was performed examining electronic databases (inception to October 2021) for studies reporting PEBN. Consistent with definitions of Post Colonoscopy Colorectal Cancer as proposed by the World Endoscopy Organization, we defined neoplasia(HGD/EAC) detected at index endoscopy and/or within 6 months of a negative index endoscopy as “prevalent” neoplasia; those detected after 6 months of a negative index endoscopy and prior to next surveillance interval(i.e. 3 years) as PEBN or “interval” neoplasia, and those detected after 36 months of a negative index endoscopy as “incident” neoplasia. Pooled incidence rates and proportion relative to total neoplasia were analyzed. Results: 11 studies (n=59,795, age:62.3±3.3 years, 61%males) met inclusion criteria. The pooled incidence rates were: prevalent neoplasia 4.5% (95%confidence interval: 2.2-8.9) at baseline and additional 0.3%(0.1-0.7) within first 6 months, PEBN 0.52%(0.48-0.58) and incident neoplasia: 1.41%(0.93-2.14). At 3 years from index endoscopy, PEBN accounted for 3% while prevalent neoplasia accounted for 97% of total Barrett’s neoplasia. Conclusion: Neoplasia detected at or within 6 months of index endoscopy account for most of the Barrett’s neoplasia(>90%). Post-Endoscopy Barrett’s Neoplasia account for ~3% of cases and can be used for validation in future. This highlights the importance of a high-quality index endoscopy in Barrett’s Esophagus and the need to establish quality benchmarks to measure endoscopists’ performance.

Risk factor-based optimal endoscopic surveillance intervals after endoscopic submucosal dissection for gastric adenoma

To date, there exists no established endoscopic surveillance interval strategy after endoscopic submucosal dissection (ESD) for gastric adenoma. In this study, we suggest a risk factor-based statistical model for optimal surveillance intervals for gastric adenoma after ESD with curative resection. A cox proportional hazard model was applied to identify risk factors for recurrence after ESD. Patients (n = 698) were categorized into groups based on the identified risk factors. The cumulative density of recurrence over time was computed using a cubic splined baseline hazard function, and the customized surveillance interval was modeled for each risk group. The overall cumulative incidence of recurrence was 7.3% (n = 51). Risk factors associated with recurrence were male (hazard ratio [HR], 2.60, P = 0.030), protruded scar (HR, 3.18, P < 0.001), and age ≥ 59 years (HR, 1.05, P < 0.001). The surveillance interval for each group was developed by using the recurrence limit for the generated risk groups. According to the developed schedule, high-risk patients would have a maximum of seven surveillance visits for 5 years, whereas low-risk patients would have biennial surveillance for cancer screening. We proposed a simple and promising strategy for determining a better endoscopic surveillance interval by parameterizing diverse and group-specific recurrence risk factors into a well-known survival model.

The location-based resect and discard strategy for diminutive colorectal polyps: a prospective clinical study

Background Clinical implementation of the resect-and-discard strategy has been difficult because optical diagnosis is highly operator dependent. This prospective study aimed to evaluate a resect-and-discard strategy that is not operator dependent. Methods The study evaluated a resect-and-discard strategy that uses the anatomical polyp location to classify colonic polyps into non-neoplastic or low risk neoplastic. All rectosigmoid diminutive polyps were considered hyperplastic and all polyps located proximally to the sigmoid colon were considered neoplastic. Surveillance interval assignments based on these a priori assumptions were compared with those based on actual pathology results and on optical diagnosis. The primary outcome was ≥ 90 % agreement with pathology in surveillance interval assignment. Results 1117 patients undergoing complete colonoscopy were included and 482 (43.1 %) had at least one diminutive polyp. Surveillance interval agreement between the location-based strategy and pathological findings using the 2020 US Multi-Society Task Force guideline was 97.0 % (95 % confidence interval [CI] 0.96–0.98), surpassing the ≥ 90 % benchmark. Optical diagnoses using the NICE and Sano classifications reached 89.1 % and 90.01 % agreement, respectively (P < 0.001), and were inferior to the location-based strategy. The location-based resect-and-discard strategy allowed a 69.7 % (95 %CI 0.67–0.72) reduction in pathology examinations compared with 55.3 % (95 %CI 0.52–0.58; NICE and Sano) and 41.9 % (95 %CI 0.39–0.45; WASP) with optical diagnosis. Conclusion The location-based resect-and-discard strategy achieved very high surveillance interval agreement with pathology-based surveillance interval assignment, surpassing the ≥ 90 % benchmark and outperforming optical diagnosis in surveillance interval agreement and the number of pathology examinations avoided.

P155 Bowel preparation is valued more than colorectal cancer risk and interval by patients in colitis-associated colorectal cancer surveillance: a discrete choice experiment

Background Patients with inflammatory bowel disease (IBD) undergo surveillance colonoscopies at fixed intervals to reduce the risk of colorectal cancer (CRC). Taking patients’ preferences for determining surveillance strategies into account could improve adherence and patient satisfaction. This study aimed to determine patient preferences and preference heterogeneity for CRC surveillance in IBD. Methods We conducted a web-based, multicentre, discrete choice experiment among adult IBD patients with an indication for surveillance, treated in two academic and one general teaching hospital in The Netherlands. Individuals were repeatedly asked to choose between three hypothetical surveillance scenarios and indicate if they would prefer this option in real-life. The choice tasks were based on bowel preparation (0.3-4L), CRC risk reduction (8% to 1–6%), and interval (1–10 years). Attribute importance scores, trade-offs, and willingness to participate were calculated using a multinomial logit model. Latent class analysis was used to identify subgroups with similar preferences. Results In total, 301 of 386 questionnaires sent out were completed and included in the study. The attributes and levels in the choice tasks significantly affected patients’ preferences. Bowel preparation was the most valued attribute (importance score 40.0%), followed by surveillance interval and CRC risk reduction (respectively 30.9% and 29.0%). Maximal CRC risk reduction, low-volume bowel preparation (0.3L laxative with 2L clear liquid) with two-yearly surveillance was the most preferred combination. Patients were willing to exchange a surveillance interval from three-yearly to annually for a CRC risk reduction of 2.9%. In latent class analysis, three subgroups were identified (figure 1). Willingness to participate in CRC surveillance was high, with only five patients (1.7%) always choosing ‘no surveillance’. Perceived high burden of bowel preparation and lower age were significantly associated with the ‘laxative avoidant’ group compared to the reference group ‘surveillance preferent’ (univariable odds ratio (OR) 2.92, 95% CI (confidence interval) 1.63–5.23 and OR 0.96, 95% CI 0.94–0.98, respectively). High level of education and age significantly differed in the ‘CRC risk avoidant’ group (univariable OR 3.77, 95% CI 2.11–6.75 and 0.94, 95% CI 0.92–0.96). Figure 1: Attribute importance scores Higher scores indicate more relative importance [0=not important at all; 100=most important] Conclusion Bowel preparation is seen as the most important factor by patients in CRC surveillance in IBD. Heterogeneity in preferences can be explained by three latent subgroups. Surveillance adherence could benefit from these findings.

Clinical validation of the SIMPLE classification for optical diagnosis of colorectal polyps

Background and study aims A novel endoscopic optical diagnosis classification system (SIMPLE) has recently been developed. This study aimed to evaluate the SIMPLE classification in a clinical cohort. Patients and methods All diminutive and small colorectal polyps found in a cohort of individuals undergoing screening, diagnostic, or surveillance colonoscopies underwent optical diagnosis using image-enhanced endoscopy (IEE) and the SIMPLE classification. The primary outcome was the agreement of surveillance intervals determined by optical diagnosis compared with pathology-based results for diminutive polyps. Secondary outcomes included the negative predictive value (NPV) for rectosigmoid adenomas, the percentage of pathology exams avoided, and the percentage of immediate surveillance interval recommendations. Analysis of optical diagnosis for polyps ≤ 10 mm was also performed. Results 399 patients (median age 62.6 years; 55.6 % female) were enrolled. For patients with at least one polyp ≤ 5 mm undergoing optical diagnosis, agreement with pathology-based surveillance intervals was 93.5 % (95 % confidence interval [CI] 91.4–95.6). The NPV for rectosigmoid adenomas was 86.7 % (95 %CI 77.5–93.2). When using optical diagnosis, pathology analysis could be avoided in 61.5 % (95 %CI 56.9–66.2) of diminutive polyps, and post-colonoscopy surveillance intervals could be given immediately to 70.9 % (95 %CI 66.5–75.4) of patients. For patients with at least one ≤ 10 mm polyp, agreement with pathology-based surveillance intervals was 92.7 % (95 %CI 89.7–95.1). NPV for rectosigmoid adenomas ≤ 10 mm was 85.1 % (95 %CI CI 76.3–91.6). Conclusions IEE with the SIMPLE classification achieved the quality benchmark for the resect and discard strategy; however, the NPV for rectosigmoid polyps requires improvement.

A118 POLYP SIZE CUT-OFF LEVEL TO IMPLEMENT OPTICAL POLYP DIAGNOSIS

Background Optical polyp diagnosis can be used for real-time pathology prediction of colorectal polyps ≤10 mm. However, the risk of misdiagnosing a polyp with advanced pathology potentially increases with increasing polyp size. Aims This study aimed to evaluate different size cut-offs for using optical polyp diagnosis and the associated risk of patients undergoing inadequate follow-up or surveillance. Methods In a post-hoc analysis of two prospective studies, the performance of optical diagnosis was evaluated in three polyp size groups: 1–3 mm, 1–5 mm, and 1–10 mm. The primary outcome was the proportion of patients with advanced adenomas and delayed or inappropriate surveillance. Secondary outcomes included percentage of polyps with advanced pathology, agreement between surveillance intervals based on high-confidence optical diagnosis and pathology outcomes, reduction in histopathological examinations, and proportion of patients who could receive an immediate surveillance interval recommendation. Results We included 1525 patients with complete colonoscopies (mean age 62.9 years, 50.2% male). The percentage of patients with advanced adenomas and delayed or inappropriate surveillance was 0.7%, 1.7%, and 1.8% when using optical diagnosis for patients with polyps of 1–3, 1–5, and 1–10 mm, respectively. The percentage of polyps with advanced pathology was 0.5%, 1.4%, and 1.9%, respectively. Surveillance interval agreement between pathology and optical diagnosis was 99%, 98%, and 97.8%, respectively. Total reduction in pathology examinations was 33.9%, 53.5%, and 69.0%, respectively. Conclusions A 3-mm cut-off for clinical implementation of optical polyp diagnosis yielded high surveillance interval agreement with pathology and a high reduction in pathology examinations while minimizing the risk of inappropriate management for polyps with advanced pathology. Funding Agencies None

A119 THE LOCATION-BASED RESECT AND DISCARD STRATEGY FOR DIMINUTIVE COLORECTAL POLYPS: A PROSPECTIVE CLINICAL STUDY

Background Replacing histopathology evaluation of diminutive polyps with optical polyp diagnosis is considered a cost-effective approach. However, the widespread use of optical diagnosis is limited due to concerns about making incorrect optical diagnoses and the requirements of training, credentialing and auditing of performance. Aims This prospective study aimed to evaluate a simplified resect and discard strategy that is not operator dependent. Methods The study evaluated a resect and discard strategy that uses anatomical polyp location to classify colon polyps into non-neoplastic or low-risk neoplastic. All rectosigmoid diminutive polyps were considered hyperplastic and all polyps located proximally to the sigmoid colon were considered neoplastic. Surveillance interval assignments based on these a priori assumptions were compared with those based on actual pathology results and optical diagnosis, respectively. The primary outcome was ≥90% agreement with pathology in surveillance interval assignment. Results Overall, 1117 patients undergoing complete colonoscopy were included and 482 (43.1%) had at least one diminutive polyp. Surveillance interval agreement between the location-based resect and discard strategy and pathological findings using the 2020 US Multi-Society Task Force guideline was 97.0% (95% CI = 0.96 - 0.98), surpassing the ≥90% benchmark. Optical diagnoses using NICE and Sano classifications reached 89.1% and 90.01% agreement, respectively (p &lt;0.0001), and were inferior to the location-based strategy. The location-based resect and discard strategy allowed a 69.7% (95% CI = 0.67 - 0.72) reduction in pathology examinations compared with 55.3% (95% CI = 0.52 - 0.58) (NICE and Sano) and 41.9% (95% CI = 0.39 - 0.45) (WASP) with optical diagnosis. Conclusions The location-based resect and discard strategy achieved very high surveillance interval agreement with pathology-based surveillance interval assignment, surpassing the ≥90% quality benchmark and outperforming optical diagnosis in surveillance interval agreement and the number of pathology examinations avoided. Funding Agencies None

Comparison of Risk of Metachronous Advanced Colorectal Neoplasia in Patients with Sporadic Adenomas Aged < 50 Versus ≥ 50 years: A Systematic Review and Meta-Analysis

No specific recommendations are available for the surveillance of young patients aged <50 years undergoing polypectomy. We aimed to compare the risk of metachronous advanced colorectal neoplasia (ACRN) between patients aged ≥50 years and those aged <50 years who underwent polypectomy. Studies published between January 1980 and June 2020 that examined the risk of metachronous ACRN were searched. We performed a meta-analysis for the metachronous ACRN risk in patients with sporadic colorectal adenomas according to the age groups (≥50 vs. <50 years). Eight individual studies were included in the meta-analysis. The risk of metachronous ACRN was higher in patients aged ≥50 years than in those aged <50 years without significant heterogeneity (odds ratio (OR) (95% CI): 1.62 (1.34–1.96), I2 = 14%). The impact of the age group on the risk of metachronous ACRN was identified in both the low-risk (LRA) and high-risk (HRA) adenoma groups (≥50 vs. <50 years: LRA, OR 1.88 (95% CI 1.30–2.70); HRA, OR 1.50 [95% CI 1.13–2.00]). In conclusion, patients aged <50 years had a lower risk of metachronous ACRN than older patients. Young patients with sporadic adenomas do not require more intensive surveillance; rather, the surveillance interval may be extended in these patients.