Sharma, Prateek

The number of artificial intelligence (AI) tools for colonoscopy on the market is increasing with supporting clinical evidence. Nevertheless, their implementation is not going smoothly for a variety of reasons, including lack of data on clinical benefits and cost‐effectiveness, lack of trustworthy guidelines, uncertain indications, and cost for implementation. To address this issue and better guide practitioners, the World Endoscopy Organization (WEO) has provided its perspective about the status of AI in colonoscopy as the position statement. WEO Position Statement: Statement 1.1: Computer‐aided detection (CADe) for colorectal polyps is likely to improve colonoscopy effectiveness by reducing adenoma miss rates and thus increase adenoma detection; Statement 1.2: In the short term, use of CADe is likely to increase health‐care costs by detecting more adenomas; Statement 1.3: In the long term, the increased cost by CADe could be balanced by savings in costs related to cancer treatment (surgery, chemotherapy, palliative care) due to CADe‐related cancer prevention; Statement 1.4: Health‐care delivery systems and authorities should evaluate the cost‐effectiveness of CADe to support its use in clinical practice; Statement 2.1: Computer‐aided diagnosis (CADx) for diminutive polyps (≤5 mm), when it has sufficient accuracy, is expected to reduce health‐care costs by reducing polypectomies, pathological examinations, or both; Statement 2.2: Health‐care delivery systems and authorities should evaluate the cost‐effectiveness of CADx to support its use in clinical practice; Statement 3: We recommend that a broad range of high‐quality cost‐effectiveness research should be undertaken to understand whether AI implementation benefits populations and societies in different health‐care systems.

Background and aims Artificial intelligence has been shown to increase adenoma detection rate (ADR) as the main surrogate outcome parameter of colonoscopy quality. To which extent this effect may be related to physician experience is not known. We performed a randomised trial with colonoscopists in their qualification period (AID-2) and compared these data with a previously published randomised trial in expert endoscopists (AID-1). Methods In this prospective, randomised controlled non-inferiority trial (AID-2), 10 non-expert endoscopists (<2000 colonoscopies) performed screening/surveillance/diagnostic colonoscopies in consecutive 40–80 year-old subjects using high-definition colonoscopy with or without a real-time deep-learning computer-aided detection (CADe) (GI Genius, Medtronic). The primary outcome was ADR in both groups with histology of resected lesions as reference. In a post-hoc analysis, data from this randomised controlled trial (RCT) were compared with data from the previous AID-1 RCT involving six experienced endoscopists in an otherwise similar setting. Results In 660 patients (62.3±10 years; men/women: 330/330) with equal distribution of study parameters, overall ADR was higher in the CADe than in the control group (53.3% vs 44.5%; relative risk (RR): 1.22; 95% CI: 1.04 to 1.40; p<0.01 for non-inferiority and p=0.02 for superiority). Similar increases were seen in adenoma numbers per colonoscopy and in small and distal lesions. No differences were observed with regards to detection of non-neoplastic lesions. When pooling these data with those from the AID-1 study, use of CADe (RR 1.29; 95% CI: 1.16 to 1.42) and colonoscopy indication, but not the level of examiner experience (RR 1.02; 95% CI: 0.89 to 1.16) were associated with ADR differences in a multivariate analysis. Conclusions In less experienced examiners, CADe assistance during colonoscopy increased ADR and a number of related polyp parameters as compared with the control group. Experience appears to play a minor role as determining factor for ADR. Trial registration number NCT:04260321.

AbstractBackground and AimRecently, the BLI Adenoma Serrated International Classification (BASIC) system was developed by European experts to differentiate colorectal polyps. Our aim was to validate the BASIC classification system among the US‐based endoscopy experts.MethodsParticipants utilized a web‐based interactive learning system where the group was asked to characterize polyps using the BASIC criteria: polyp surface (presence of mucus, regular/irregular and [pseudo]depressed), pit appearance (featureless, round/non‐round with/without dark spots; homogeneous/heterogeneous distribution with/without focal loss), and vessels (present/absent, lacy, peri‐cryptal, irregular). The final testing consisted of reviewing BLI images/videos to determine whether the criteria accurately predicted the histology results. Confidence in adenoma identification (rated “1” to “5”) and agreement in polyp (adenoma vs non‐adenoma) identification and characterization per BASIC criteria were derived. Strength of interobserver agreement with kappa (k) value was reported for adenoma identification.ResultsTen endoscopy experts from the United States identified conventional adenoma (vs non‐adenoma) with 94.4% accuracy, 95.0% sensitivity, 93.8% specificity, 93.8% positive predictive value, and 94.9% negative predictive value using BASIC criteria. Overall strength of interobserver agreement was high: kappa 0.89 (0.82–0.96). Agreement for the individual criteria was as follows: surface mucus (93.8%), regularity (65.6%), type of pit (40.6%), pit visibility (66.9%), pit distribution (57%), vessel visibility (73%), and being lacy (46%) and peri‐cryptal (61%). The confidence in diagnosis was rated at high ≥4 in 67% of the cases.ConclusionsA group of US‐based endoscopy experts have validated a simple and easily reproducible BLI classification system to characterize colorectal polyps with >90% accuracy and a high level of interobserver agreement.

INTRODUCTION: Endoscopic surveillance guidelines in Barrett’s esophagus (BE) to detect progression to high grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) are based solely on dysplasia grade. Given low rates of progression, identification of predictors (and scores) of progression may help to focus surveillance or intervention in those at higher risk. We aimed to assess predictors of progression and externally validate the Progression in Barrett’s (PIB) score in an independent multicenter prospective BE and EAC cohort. METHODS: The EA and Barrett’s esophagus (EABE) registry is a prospective cohort of patients recruited from three medical centers. Progressors were defined as those with the development of HGD or EAC more than 12 months after initial diagnosis. Demographic and clinical variables were abstracted. The annual incidence rate and predictors of progression were assessed using univariate and multivariable Cox proportional hazards analysis. The ability of the PIB score (incorporating weighted scores for male gender, smoking (ever versus never), BE length and confirmed LGD) to risk stratify the cohort into low (0-10 points), intermediate (11-20 points) and high risk (> 20 points) groups was assessed. RESULTS: 429 patients were included. 84% were men, with a mean (SD) age of 61.5 (9.9) years. 65% were ever smokers and most (76.7%), had NDBE at diagnosis. Mean (SD) maximal BE segment length was 5.9 (3.2) cm. Eighty-two patients (19.1%) progressed to HGD (n = 65) or EAC (n = 17) over a median (IQR) follow up of 7.5 (3.7, 12.5) years. Annual incidence rates of progression to EAC and EAC/HGD were 0.5% and 2.0% respectively. Univariate and multivariable predictors of progression are displayed in Table 1. The PIB score divided patients into three groups (Table 2) with progressively increasing rates of progression. The risk in the high risk group was three fold higher than the low risk group ( P = 0.024). The risk in the intermediate group was twofold higher but not statistically significantly higher ( P = 0.13). The PIB score had a c-statistic score of 0.76 in the original cohort. In this cohort the c-statistic value was lower at 0.64, suggesting moderate performance. CONCLUSION: Male sex and BE length predicted progression in this independent multicenter cohort. The PIB score was also able to risk-stratify patients in this validation cohort with the high risk cohort being 3x more likely to progress compared to the low risk cohort.

Abstract Background An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200 mg MB-MMX added to their bowel prep. Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results Ten patients were included in the study. The mean expression of γH2AX ± 95 % confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P = 0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions An oral dose of 200 mg of MB-MMX did not result in any detectable DNA damage.