Even non-experts identify non-dysplastic lesions in inflammatory bowel disease via chromoendoscopy: results of a screening program in real-life

Artificial intelligence for dysplasia detection during surveillance colonoscopy in patients with ulcerative colitis: A cross-sectional, non-inferiority, diagnostic test comparison study

BACKGROUND AND STUDY AIM

High-definition virtual chromoendoscopy, along with targeted biopsies, is recommended for dysplasia surveillance in ulcerative colitis patients at risk for colorectal cancer. Computer-aided detection (CADe) systems aim to improve colonic adenoma detection, however their efficacy in detecting polyps and adenomas in this context remains unclear. This study evaluates the CADe Discovery™ system's effectiveness in detecting colonic dysplasia in ulcerative colitis patients at risk for colorectal cancer.

PATIENTS AND METHODS

A prospective cross-sectional, non-inferiority, diagnostic test comparison study was conducted on ulcerative colitis patients undergoing colorectal cancer surveillance colonoscopy between January 2021 and April 2021. Patients underwent virtual chromoendoscopy (VCE) with iSCAN 1 and 3 with optical enhancement. One endoscopist, blinded to CADe Discovery™ system results, examined colon sections, while a second endoscopist concurrently reviewed CADe images. Suspicious areas detected by both techniques underwent resection. Proportions of dysplastic lesions and patients with dysplasia detected by VCE or CADe were calculated.

RESULTS

Fifty-two patients were included, and 48 lesions analyzed. VCE and CADe each detected 9 cases of dysplasia (21.4% and 20.0%, respectively; p=0.629) in 8 patients and 7 patients (15.4% vs. 13.5%, respectively; p=0.713). Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy for dysplasia detection using VCE or CADe were 90% and 90%, 13% and 5%, 21% and 2%, 83% and 67%, and 29.2% and 22.9%, respectively.

CONCLUSIONS

The CADe Discovery™ system shows similar diagnostic performance to VCE with iSCAN in detecting colonic dysplasia in ulcerative colitis patients at risk for colorectal cancer.

Low risk of new dysplastic lesions in an inflammatory bowel disease population study with dye chromoendoscopy

Background and study aims  Rates of new dysplastic lesions or cancer progression after first dye chromoendoscopy in the era of high-definition endoscopy have yet to be determined. Patients and methods  A multicenter, population-based, retrospective cohort study was performed in seven hospitals in Spain. Patients with inflammatory bowel disease and fully resected (R0) dysplastic colon lesions under surveillance with high-definition dye-based chromoendoscopy were sequentially enrolled between February 2011 and June 2017, with a minimum endoscopic follow-up of 36 months. The aim was to assess the incidence of developing more advanced metachronous neoplasia by analyzing possible associated risk factors. Results  The study sample included 99 patients and 148 index lesions (145 low-grade dysplasia lesions and three high-grade dysplasia [HGD] lesions with a mean follow-up of 48.76 months [IQR: 36.34-67.15]). The overall incidence of new dysplastic lesions was 0.23 per 100 patient-years, 1.15 per 100 patients at 5 years and 2.29 per 100 patients at 10 years. A history of dysplasia was associated with a higher risk of developing any grade of dysplasia during follow-up ( P  = 0.025), whereas left colon lesions were associated with a lower risk ( P  = 0.043). The incidence of more advanced lesions at 1 year and 10 years was 1 % and 14 % respectively, with lesion size > 1 cm being a risk factor ( P  = 0.041). One of the eight patients (13 %) with HGD lesions developed colorectal cancer during follow-up. Conclusions  The risk of dysplasia progressing to advanced neoplasia and, specifically, the risk of new neoplastic lesions after endoscopic resection of colitis-associated dysplasia, are both very low.

Endoscopic management of patients with high-risk colorectal colitis-associated neoplasia: a Delphi study

BACKGROUND AND AIMS

Current guidelines recommend endoscopic resection of visible and endoscopically resectable colorectal colitis-associated neoplasia (CAN) in patients with inflammatory bowel disease (IBD). However, patients with high-risk CAN (HR-CAN) are often not amenable to conventional resection techniques, and a consensus approach for the endoscopic management of these lesions is presently lacking. This Delphi study aims to reach consensus among experts on the endoscopic management of these lesions.

METHODS

A 3-round modified Delphi process was conducted to reach consensus among worldwide IBD and/or endoscopy experts (n = 18) from 3 continents. Consensus was considered if ≥75% agreed or disagreed. Quality of evidence was assessed by the criteria of the Cochrane Collaboration group.

RESULTS

Consensus was reached on all statements (n = 14). Experts agreed on a definition for CAN and HR-CAN. Consensus was reached on the examination of the colon with enhanced endoscopic imaging before resection, the endoscopic resectability of an HR-CAN lesion, and endoscopic assessment and standard report of CAN lesions. In addition, experts agreed on type of resections of HR-CAN (< 20 mm, >20 mm, with or without good lifting), endoscopic success (technical success and outcomes), histologic assessment, and follow-up in HR-CAN.

CONCLUSIONS

This is the first step in developing international consensus-based recommendations for endoscopic management of CAN and HR-CAN. Although the quality of available evidence was considered low, consensus was reached on several aspects of the management of CAN and HR-CAN. The present work and proposed standardization might benefit future studies.

Evolving roles of magnifying endoscopy and endoscopic resection for neoplasia in inflammatory bowel diseases

Magnifying endoscopy is a useful technique to differentiate neoplasia from non-neoplastic lesions. Data regarding the clinical utility of magnifying endoscopy for neoplasia in patients with inflammatory bowel disease (IBD) has been emerging. While Kudo's pit pattern types III-V are findings suggestive of neoplasia in non-IBD patients, these pit patterns are predictive of IBD-associated neoplasia as well. However, active chronic inflammatory processes, particularly regenerative changes, can mimic neoplastic pit patterns and may affect a meticulous evaluation of pit pattern diagnosis in patients with IBD. The clinical evidence regarding the utility of magnifying endoscopy with narrow band imaging or endocytoscopy has also been evolving in regard to the diagnosis of IBD-associated neoplasia. These advanced endoscopic techniques are promising for multiple reasons; not only for making an accurate diagnosis of neoplasia, but also in determining if endoscopic resection is appropriate for such lesions in patients with IBD. In this review, we discuss the diagnostic accuracy and limitations of magnifying endoscopy in assessing IBD-associated neoplasia and examine the feasibility and outcomes of endoscopic resection for these lesions.

Colorectal cancer surveillance with chromoendoscopy in inflammatory bowel disease: results from a real-life experience

BACKGROUND

Patients with inflammatory bowel disease are at increased risk for colorectal cancer. The aim of this study was to know the prevalence of dysplasia and colorectal cancer with chromoendoscopy, to describe the characteristics and the management of the detected lesions and to identify possible risk factors of dysplasia in clinical practice.

METHODS

Observational, retrospective study of all chromoendoscopies performed between January 2016 and May 2019 in patients with left-sided/extensive ulcerative colitis or Crohn's disease involving more than one-third of the colon. Information about all the polyps' characteristics and the treatments received was collected.

RESULTS

A total of 186 chromoendoscopies on 160 patients were reviewed; 57% were men; 54% had ulcerative colitis. The dysplasia detection rate was 24% and 212 lesions were detected: rectum (36%) and left colon (30%). Flat polyps were detected in 57% patients. In total, 123 (62%) lesions were non-neoplastic and 74 (38%) were neoplastic. Among these, 69 (93%) were low grade dysplasia and five (7%) were high grade dysplasia, all of them located in rectum. Two patients (1%) required surgery. During follow-up, no patient developed colorectal cancer. Age over 60 years, flat lesions, polyp >5 mm and right colon localization were found to be risk factors for dysplasia.

CONCLUSIONS

This study reports a high dysplasia detection rate (24%) via targeted chromoendoscopic biopsies. In most cases, lesions were successfully removed by endoscopic resection. Our results underline the importance of colorectal cancer surveillance in inflammatory bowel disease patients.

Recommendations of the Spanish Working Group on Crohn's disease and Ulcerative Colitis (Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa - GETECCU) on dysplasia screening in inflammatory bowel disease patients

Colonic inflammatory bowel diseases have a higher risk of developing colorectal cancer compared to the general population, which is why they require endoscopic screening techniques with specific follow-up intervals based on the different risk factors described on the literature. This position paper analyzes the current scientific evidence for the different endoscopic techniques available today, how their implementation should be carried out in endoscopic units and describes in detail how their implementation should be carried out, in which patients and with what interval, and finally, what should be the response to finding dysplasia, proposing a specific follow-up algorithm.