Advanced imaging for detection and differentiation of colorectal neoplasia: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

Endoscopic management of patients with familial adenomatous polyposis after prophylactic colectomy or restorative proctocolectomy - systematic review of the literature

BACKGROUND

Patients with familial adenomatous polyposis (FAP) develop early colorectal adenomas and if left untreated, progression to cancer is an inevitable event. Prophylactic surgery does not prevent further development of cancer in the rectal remnant, rectal cuff in patients with ileal pouch anal anastomosis (IPAA) and even on the ileal mucosa of the pouch body. The aim of this review is to assess long-term rates of cancer and adenoma development in patients with FAP after prophylactic surgery and to summarise current recommendations for endoscopic management and surveillance of these patients.

MATERIALS AND METHODS

A systematic literature search of studies from January 1946 through to June 2023 was conducted using the PRISMA checklist. The electronic database PubMed was searched.

RESULTS

Fifty-four papers involving 5010 patients were reviewed. Cancer rate in the rectal remnant was 8.8-16.7% in the western population and 37% in the eastern population. The cumulative risk of cancer 30 years after surgery was 24%. Mortality due to cancer in the rectal remnant is 1.1-11.1% with a 5-year survival rate of 55%. The adenoma rate after primary IPAA was 9.4-85% with a cumulative risk of 85% 20 years after surgery and a cumulative risk of 12% for advanced adenomas 10 years after surgery. Cumulative risk for adenomas after ileorectal anastomosis (IRA) was 85% after 5 and 100% after 10 years. Adenomas developed more frequently after stapled (33.9-57%) compared to hand-sewn (0-33%) anastomosis. We identified reports of 45 cancers in patients after IPAA of which 30 were in the pouch body and 15 in the rectal cuff or at the anastomosis.

CONCLUSIONS

There was a significant incidence of cancer and adenomas in the rectal remnant and ileal pouch of FAP patients during the long-term follow-up. Regular endoscopic surveillance is recommended, not only in IRA patients, but also in pouch patients after proctocolectomy.

Emerge of colorectal cancer in Lynch syndrome despite colonoscopy surveillance: A challenge of hide and seek

Even with colonoscopy surveillance, Lynch syndromes (LS) carriers still develop colorectal cancer (CRC). The cumulative incidence of CRCs under colonoscopy surveillance varies depending on the affected mismatch repair (MMR) gene. However, the precise mechanisms driving these epidemiological patterns remain incompletely understood. In recent years, several potential mechanisms explaining the occurrence of CRCs during colonoscopy surveillance have been proposed in individuals with and without LS. These encompass biological factors like concealed/accelerated carcinogenesis through a bypassed adenoma stage and accelerated progression from adenomas. Alongside these, various colonoscopy-related factors may contribute to formation of CRCs under colonoscopy surveillance, like missed yet detectable (pre)cancerous lesions, detected yet incompletely removed (pre)cancerous lesions, and colonoscopy-induced carcinogenesis due to tumor cell reimplantation. In this comprehensive literature update, we reviewed these potential factors and evaluated their relevance to each MMR group in an attempt to raise further awareness and stimulate research regarding this conflicting phenomenon.

Non-metastatic colon cancer: French Intergroup Clinical Practice Guidelines for diagnosis, treatments, and follow-up (TNCD, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFP, AFEF, and SFR)

INTRODUCTION

This article is a summary of the French intergroup guidelines regarding the management of non-metastatic colon cancer (CC), revised in November 2022.

METHODS

These guidelines represent collaborative work of all French medical and surgical societies involved in the management of CC. Recommendations were graded in three categories (A, B, and C) according to the level of evidence found in the literature published up to November 2022.

RESULTS

Initial evaluation of CC is based on clinical examination, colonoscopy, chest-abdomen-pelvis computed tomography (CT) scan, and carcinoembryonic antigen (CEA) assay. CC is usually managed by surgery and adjuvant treatment depending on the pathological findings. The use of adjuvant therapy remains a challenging question in stage II disease. For high-risk stage II CC, adjuvant chemotherapy must be discussed and fluoropyrimidine monotherapy or oxaliplatin-based chemotherapy proposed according to the type and number of poor prognostic features. Oxaliplatin-based chemotherapy (FOLFOX or CAPOX) is the current standard for adjuvant therapy of patients with stage III CC. However, these regimens are associated with significant oxaliplatin-induced neurotoxicity. The results of the recent IDEA study provide evidence that 3 months of treatment with CAPOX is as effective as 6 months of oxaliplatin-based therapy in patients with low-risk stage III CC (T1-3 and N1). A 6-month oxaliplatin-based therapy remains the standard of care for high-risk stage III CC (T4 and/or N2). For patients unfit for oxaliplatin, fluoropyrimidine monotherapy is recommended.

CONCLUSION

French guidelines for non-metastatic CC management help to offer the best personalized therapeutic strategy in daily clinical practice. Each individual case must be discussed within a multidisciplinary tumor board and then the treatment option decided with the patient.

Colorectal cancer: Genetic alterations, novel biomarkers, current therapeutic strategies and clinical trials

Colorectal cancer (CRC) is the third most commonly detected cancer with a serious global health issue. The rates for incidence and mortality for CRC are alarming, especially since the prognosis is abysmal when the CRC is diagnosed at an advanced or metastatic stage. Both type of (modifiable/ non-modifiable) types of risk factors are established for CRC. Despite the advances in recent technology and sophisticated research, the survival rate is still meager due to delays in diagnosis. Therefore, there is urgently required to identify critical biomarkers aiming at early diagnosis and improving effective therapeutic strategies. Additionally, a complete understanding of the dysregulated pathways like PI3K/Akt, Notch, and Wnt associated with CRC progression and metastasis is very beneficial in designing a therapeutic regimen. This review article focused on the dysregulated signaling pathways, genetics and epigenetics alterations, and crucial biomarkers of CRC. This review also provided the list of clinical trials targeting signaling cascades and therapies involving small molecules. This review discusses up-to-date information on novel diagnostic and therapeutic strategies alongside specific clinical trials.

Narrow Band Imaging versus White Light for the Detection of Sessile Serrated Colorectal Lesions: A Randomized Clinical Trial

Background

Colorectal cancer (CRC) is a leading cause of cancer. The detection of pre-malignant lesions by colonoscopy is associated with reduced CRC incidence and mortality. Narrow band imaging has shown promising but conflicting results for the detection of serrated lesions.

Methods

We performed a randomized clinical trial to compare the mean detection of serrated lesions and hyperplastic polyps ≥10 mm with NBI or high-definition white light (HD-WL) withdrawal. We also compared all sessile serrated lesions (SSLs), adenoma, and polyp prevalence and rates.

Results

Overall, 782 patients were randomized (WL group 392 patients; NBI group 390 patients). The average number of serrated lesions and hyperplastic polyps ≥10 mm detected per colonoscopy (primary endpoint) was similar between the HD-WL and NBI group (0.118 vs. 0.156, p = 0.44). Likewise, the adenoma detection rate (55.2% vs. 53.2%, p = 0.58) and SSL detection rate (6.8% vs. 7.5%, p = 0.502) were not different between the two study groups. Withdrawal time was higher in the NBI group (10.88 vs. 9.47 min, p = 0.004), with a statistically nonsignificant higher total procedure time (20.97 vs. 19.30 min, p = 0.052).

Conclusions

The routine utilization of narrow band imaging does not improve the detection of serrated class lesions or any pre-malignant lesion and increases the withdrawal time.

Cold resection for colorectal polyps: where we are and where we are going?

INTRODUCTION

Endoscopic resection of colonic precancerous lesions has been demonstrated to significantly decrease colorectal cancer (CRC) incidence and mortality. Among resection techniques, cold snare polypectomy (CSP) has been shown as a highly feasible, effective and safe option and is widely used in clinical practice, being regarded as the first-line technique for removal of small and diminutive colorectal polyps. On the other hand, conventional hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR), namely the gold standard treatments for larger polyps, may be occasionally associated to complications due to electrocautery injury.

AREAS COVERED

To overcome these shortcomings of electrocautery-based resection techniques, in the last few years CSP has been increasingly assessed as a treatment option for additional indications, with a focus on nonpedunculated colorectal polyps ≥10 mm.

EXPERT OPINION

This review aims to present current and widened indications of CSP discussing the latest findings from the most remarkable studies, with an insight into technical issues, novelties and potential advances in the near future.

Effect of pre-resection biopsy on detection of advanced dysplasia in large nonpedunculated colorectal polyps undergoing endoscopic mucosal resection

BACKGROUND : Pre-resection biopsy (PRB) of large nonpedunculated colorectal polyps (LNPCPs, ≥ 20 mm) is often performed before referral for endoscopic mucosal resection (EMR). How this affects the EMR procedure is unknown. METHODS : This was a retrospective analysis of a prospectively collected cohort of patients with LNPCPs referred for EMR between 2013 to 2016 at an Australian tertiary center. Outcomes were differences between PRB and EMR histology, and effects of PRB on the EMR procedure. RESULTS:  Among 586 LNPCPs, lesions that underwent PRB were larger (median 35 vs. 30 mm; P < 0.007), and more commonly morphologically flat or slightly elevated (P = 0.01) compared with lesions without PRB. PRB histology was upstaged in 26.1 %, downstaged in 13.8 %, and unchanged in 60.1 % after EMR. Sensitivity of PRB was 77.2 % (95 %CI 71.1-82.4) for low grade dysplasia (LGD) and 21.2 % (95 %CI 11.5-35.1) for high grade dysplasia (HGD). Where EMR specimen showed HGD, PRB had detected LGD in 76.9 %. Where EMR specimen showed cancer, PRB had detected dysplasia only. PRB was associated with more submucosal fibrosis (P = 0.001) and intraprocedural bleeding (P = 0.03). EMR success or recurrence was not affected. CONCLUSIONS:  Routine PRB of LNPCP did not reliably detect advanced histology and may have affected EMR complexity. PRB should be utilized with caution in guiding endoscopic management of LNPCPs.

Accuracy and Inter-observer Agreement Among Endoscopists for Visual Identification of Colorectal Polyps Using Endoscopy Images

BACKGROUND

It is essential to accurately distinguish small benign hyperplastic colon polyps (HP) from sessile serrated lesions (SSL) or adenomatous polyps (TA) based on endoscopic appearances. Our objective was to determine the accuracy and inter-observer agreements for the endoscopic diagnosis of small polyps.

METHODS

High-quality endoscopic images of 30 small HPs, SSLs, and TAs were used randomly to create two-timed PowerPoint slide sets-one with and another one without information on polyp size and location. Seven endoscopists viewed the slides on two separate occasions 90 days apart, identified the polyp type, and graded their confidence level. Overall and polyp-specific accuracies were assessed for the group and individual endoscopists. Chi-square tests and Kappa (κ) statistics were used to compare differences as appropriate.

RESULTS

When polyp size and location were provided, overall accuracy was 67.1% for TAs, 50.0% for SSLs, and 41.4% for HPs; the corresponding accuracies were 60%, 44.3%, and 34.3% when polyp size and location were withheld (p < .001). Inter-observer agreement was moderate for TAs (κ = 0.50) and fair for SSLs (κ = 0.26) and HPs (κ = 0.29); the corresponding inter-observer agreements were 0.44, 0.31, and 0.17 with polyp size and location withheld. Accuracy was not affected by knowledge of polyp size, location, or confidence level. Endoscopists with ≥ 10 years (vs. < 10 years) of colonoscopy experience had marginally higher (56% vs. 40%, p = 0.05) accuracy for SSL diagnosis.

CONCLUSIONS

The ability to distinguish between small TAs, SSLs, and HPs on their endoscopic appearance is poor regardless of the endoscopists' knowledge of polyp size and location.

Virtual indigo carmine dyeing: New artificial intelligence-based chromoendoscopy technique

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Implementation of optical diagnosis with a "resect and discard" strategy in clinical practice: DISCARD3 study

BACKGROUND AND AIMS

Optical diagnosis (OD) of polyps can be performed with advanced endoscopic imaging. For high-confidence diagnoses, a "resect and discard" strategy could offer significant histopathology time and cost savings. The implementation threshold is a ≥90% OD-histology surveillance interval concordance. Here we assessed the OD learning curve and feasibility of a resect and discard strategy for ≤5-mm and <10-mm polyps in a bowel cancer screening setting.

METHODS

In this prospective feasibility study, 8 bowel cancer screening endoscopists completed a validated OD training module and performed procedures. All <10-mm consecutive polyps had white-light and narrow-band images taken and were given high- or low-confidence diagnoses until 120 high-confidence ≤5-mm polyp diagnoses had been performed. All polyps had standard histology. High-confidence OD errors underwent root-cause analysis. Histology and OD-derived surveillance intervals were calculated.

RESULTS

Of 565 invited patients, 525 patients were included. A total of 1560 <10-mm polyps underwent OD and were resected and retrieved (1329 ≤5 mm and 231 6-9 mm). There were no <10-mm polyp cancers. High-confidence OD was accurate in 81.5% of ≤5-mm and 92.8% of 6-9-mm polyps. Sensitivity for OD of a ≤5-mm adenoma was 93.0% with a positive predictive value of 90.8%. OD-histology surveillance interval concordance for ≤5-mm OD was 91.3% (209/229) for U.S. Multi-Society Task Force, 98.3% (225/229) for European Society of Gastrointestinal Endoscopy, and 98.7% (226/229) for British Society of Gastroenterology guidelines, respectively.

CONCLUSIONS

A resect and discard strategy for high-confidence ≤5-mm polyp OD in a group of bowel cancer screening colonoscopists is feasible and safe, with performance exceeding the 90% surveillance interval concordance required for implementation in clinical practice. (Clinical trial registration number: NCT04710693.).

A SWOT analysis of artificial intelligence in diagnostic imaging in the developing world: making a case for a paradigm shift

Diagnostic imaging (DI) refers to techniques and methods of creating images of the body’s internal parts and organs with or without the use of ionizing radiation, for purposes of diagnosing, monitoring and characterizing diseases. By default, DI equipment are technology based and in recent times, there has been widespread automation of DI operations in high-income countries while low and middle-income countries (LMICs) are yet to gain traction in automated DI. Advanced DI techniques employ artificial intelligence (AI) protocols to enable imaging equipment perceive data more accurately than humans do, and yet automatically or under expert evaluation, make clinical decisions such as diagnosis and characterization of diseases. In this narrative review, SWOT analysis is used to examine the strengths, weaknesses, opportunities and threats associated with the deployment of AI-based DI protocols in LMICs. Drawing from this analysis, a case is then made to justify the need for widespread AI applications in DI in resource-poor settings. Among other strengths discussed, AI-based DI systems could enhance accuracies in diagnosis, monitoring, characterization of diseases and offer efficient image acquisition, processing, segmentation and analysis procedures, but may have weaknesses regarding the need for big data, huge initial and maintenance costs, and inadequate technical expertise of professionals. They present opportunities for synthetic modality transfer, increased access to imaging services, and protocol optimization; and threats of input training data biases, lack of regulatory frameworks and perceived fear of job losses among DI professionals. The analysis showed that successful integration of AI in DI procedures could position LMICs towards achievement of universal health coverage by 2030/2035. LMICs will however have to learn from the experiences of advanced settings, train critical staff in relevant areas of AI and proceed to develop in-house AI systems with all relevant stakeholders onboard.

Image-enhanced endoscopy and endoscopic resection practices in the colon among endoscopists in India

Background and study aims  Clinical practice patterns for image-enhanced endoscopy (IEE) and colonic endoscopic resection practices vary among endoscopists. We conducted a survey to understand the differences in IEE and colonoscopic resection practices among endoscopists from India. Methods  An online cross-sectional survey comprising 40 questions regarding quality control of colonoscopy, IEE, and colonic endoscopic resection practices was circulated through the registry of the Indian Society of Gastroenterology and Association of Colon and Rectal Surgeons of India. Participation was voluntary and response to all questions was compulsory. Results  There were 205 respondents to the survey (93.2 % gastroenterologists, 90.2 % male, 54.6 % aged 30 to 40 years, 36.1 % working in academic institution, 36.1 % working in corporate hospitals). Of the endoscopists, 50.7 % had no training in IEE and 10.7 % performed endoscopy on systems without any IEE modalities. Endoscopists with more experience were more likely to use IEE modalities in practice routinely ( P  = 0.007). Twenty percent never used IEE to classify polyps. Sixty percent of respondents did not use dye-chromoendoscopy. Less experienced endoscopists used viscous solutions as submucosal injectate ( P  = 0.036) more often. Of the respondents, 44 % never tattooed the site of endoscopic resection. Ablation of edges post-endoscopic mucosal resection was not done by 25.5 % respondents. Most respondents used electronic chromoendoscopy (36.1 %) or random four-quadrant sampling (35.6 %) for surveillance in inflammatory bowel disease. Surveillance post-endoscopic resection was done arbitrarily by 24 % respondents at 6 months to 1 year. Conclusions  There are several lacunae in the practice of IEE and colonic endoscopic resection among endoscopists, with need for programs for privileging, credentialing and proctoring these endoscopic skills.

Adenoma detection rate using narrow-band imaging is inferior to high-definition white light colonoscopy in screening and surveillance colonoscopies in daily clinical care: A randomized controlled trial

BACKGROUND

Despite recent advances in endoscopic technology adenoma miss rate still is up to 20% contributing to interval cancers. Improved imaging modalities have been introduced to increase adenoma detection rate (ADR). Recently, narrow-band imaging (NBI) (Exera II series, Olympus Corporation) was not significantly better than high-definition white light colonoscopy (HD-WLC). An improved second generation of NBI (190-NBI) is characterized by better illumination of the bowel lumen and may be associated with a higher ADR.

METHODS

We performed a prospective randomized study on patients referred to the Jena University Hospital for screening or surveillance colonoscopy between January 2015 and April 2017. Participating endoscopists were divided into 2 subgroups depending on their individual experience. Colonoscopy was performed by use of HD-WLC or 190-NBI upon withdrawal.

RESULTS

Five hundred fifty-three patients participated in the study. Eighty patients were excluded (insufficient bowel cleansing [n = 34], anticoagulation precluding polypectomy [n=15], partial colonic resection [n=9], other reasons [n = 22]). Mean age was 66.9 years (standard deviation 10.3 years), and 253 patients were male (53.5%). Bowel preparation and withdrawal time were not different. ADR among all subgroups was 39.4% using HD-WLC, but only 29.1% were using 190-NBI (P = .02). Number of polyps per patient was lower using 190-NBI than with HD-WLC (0.58 vs 0.86; P = .02). Subgroup analysis revealed that 190-NBI was inferior to HD-WLC only in unexperienced endoscopists.

CONCLUSION

In our stud,y ADR was lower by use of 190-NBI. These differences persisted only in unexperienced investigators. 190-NBI seems to be more challenging regarding ADR, requiring more intensive training prior to implementing this technology in daily clinical care.

REGISTRATION

ClinicalTrials.gov (identifier: NCT03081975).

Real-time, computer-aided, detection-assisted colonoscopy eliminates differences in adenoma detection rate between trainee and experienced endoscopists

Background and study aims  Adenoma detection rate (ADR) is a well-accepted quality indicator of screening colonoscopy. In recent years, the added value of artificial intelligence (AI) has been demonstrated in terms of ADR and adenoma miss rate (AMR). To date, there are no studies evaluating the impact of AI on the performance of trainee endoscopists (TEs). This study aimed to assess whether AI might eliminate any difference in ADR or AMR between TEs and experienced endoscopists (EEs). Patients and methods  We performed a prospective observational study in 45 subjects referred for screening colonoscopy. A same-day tandem examination was carried out for each patient by a TE with the AI assistance and subsequently by an EE unaware of the lesions detected by the TE. Besides ADR and AMR, we also calculated for each subgroup of endoscopists the adenoma per colonoscopy (APC), polyp detection rate (PDR), polyp per colonoscopy (PPC) and polyp miss rate (PMR). Subgroup analyses according to size, morphology, and site were also performed. Results  ADR, APC, PDR, and PPC of AI-supported TEs were 38 %, 0.93, 62 %, 1.93, respectively. The corresponding parameters for EEs were 40 %, 1.07, 58 %, 2.22. No significant difference was found for each analysis between the two groups ( P  > 0.05). AMR and PMR for AI-assisted TEs were 12.5 % and 13 %, respectively. Sub-analyses did not show any significant difference ( P  > 0.05) between the two categories of operators. Conclusions  In this single-center prospective study, the possible impact of AI on endoscopist quality training was demonstrated. In the future, this could result in better efficacy of screening colonoscopy by reducing the incidence of interval or missed cancers.

Factors Associated with Polyp Detection Rate in European Colonoscopy Practice: Findings of The European Colonoscopy Quality Investigation (ECQI) Group

Background: The European Colonoscopy Quality Investigation (ECQI) Group aims to raise awareness for improvement in colonoscopy standards across Europe. We analysed data collected on a sample of procedures conducted across Europe to evaluate the achievement of the polyp detection rate (PDR) target. We also investigated factors associated with PDR, in the hope of establishing areas that could lead to a quality improvement. Methods: 6445 form completions from 12 countries between 2 June 2016 and 30 April 2018 were considered for this analysis. We performed an exploratory analysis looking at PDR according to European Society of Gastrointestinal Endoscopy (ESGE) definition. Stepwise multivariable logistic regression analysis was conducted to determine the most influential associated factors after adjusting for the other pre-specified variables. Results: In our sample there were 3365 screening and diagnostic procedures performed in those over 50 years. The PDR was 40.5%, which is comparable with the ESGE minimum standard of 40%. The variables found to be associated with PDR were in descending order: use of high-definition equipment, body mass index (BMI), patient gender, age group, and the reason for the procedure. Use of HD equipment was associated with a significant increase in the reporting of flat lesions (14.3% vs. 5.7%, p < 0.0001) and protruded lesions (34.7% vs. 25.4%, p < 0.0001). Conclusions: On average, the sample of European practice captured by the ECQI survey meets the minimum PDR standard set by the ESGE. Our findings support the ESGE recommendation for routine use of HD colonoscopy.

Colorectal cancer screening and surveillance in patients with inflammatory bowel disease in 2021

The detection of dysplasia in patients with inflammatory bowel disease (IBD) continues to be important given the increased risk of colorectal cancer in this population. Therefore, in 2017, we performed a review and update of the recommendations for the management and follow-up of patients with IBD based on the clinical practice guidelines of various scientific societies. The present manuscript focuses on new aspects of the detection, follow-up, and management of dysplasia according to the latest studies and recommendations. While chromoendoscopy with targeted biopsy continues to be the technique of choice for the screening and detection of dysplasia in IBD, the associated difficulties mean that it is now being compared with other techniques (virtual chromoendoscopy), which yield similar results with less technical difficulties. Furthermore, the emergence of new endoscopy techniques that are still being researched but seem promising (e.g., confocal laser endomicroscopy and full-spectrum endoscopy), together with the development of devices that improve endoscopic visualization (e.g., Endocuff Vision), lead us to believe that these approaches can revolutionize the screening and follow-up of dysplasia in patients with IBD. Nevertheless, further studies are warranted to define the optimal follow-up strategy in this patient population.

The COlorectal NEoplasia Endoscopic Classification to Choose the Treatment classification for identification of large laterally spreading lesions lacking submucosal carcinomas: A prospective study of 663 lesions

Introduction

Optical diagnosis is necessary when selecting the resection modality for large superficial colorectal lesions. The COlorectal NEoplasia Endoscopic Classification to Choose the Treatment (CONECCT) encompasses overt (irregular pit or vascular pattern) and covert (macroscopic features) signs of carcinoma in an all‐in‐one classification using validated criteria. The CONECCT IIC subtype corresponds to adenomas with a high risk of superficial carcinoma that should be resected en bloc with free margins.

Methods

This prospective multicentre study investigated the diagnostic accuracy of the CONECCT classification for predicting submucosal invasion in colorectal lesions >20 mm. Optical diagnosis before en bloc resection by endoscopic submucosal dissection (ESD) was compared with the final histological diagnosis. Diagnostic accuracy for the CONECCT IIC subtype was compared with literature‐validated features of concern considered to be risk factors for submucosal invasion (non‐granular large spreading tumour [NG LST], macronodule >1 cm, SANO IIIA area, and Paris 0‐IIC area).

Results

Six hundred 63 lesions removed by ESD were assessed. The en bloc, R0, and curative resection rates were respectively 96%, 85%, and 81%. The CONECCT classification had a sensitivity (Se) of 100%, specificity (Sp) of 26.2%, positive predictive value of 11.6%, and negative predictive value (NPV) of 100% for predicting at least submucosal adenocarcinoma. The sensitivity of CONECCT IIC (100%) to predict submucosal cancer was superior to all other criteria evaluated. COlorectal NEoplasia Endoscopic Classification to Choose the Treatment IIC lesions constituted 11.5% of all submucosal carcinomas.

Conclusion

The CONECCT classification, which combines covert and overt signs of carcinoma, identifies with very perfect sensitivity (Se 100%, NPV 100%) the 30% of low‐risk adenomas in large laterally spreading lesions treatable by piecemeal endoscopic mucosal resection or ESD according to expertise without undertreatment. However, the low specificity of CONECCT leads to a large number of potentially not indicated ESDs for suspected high‐risk lesions.

Electronic chromo-endoscopy: technical details and a clinical perspective

Precise endoscopic assessment is necessary to detect neoplastic changes in an early stage. Electronic or virtual chromo-endoscopy (ECE) is an alternative to conventional dye-based chromo-endoscopy which markedly improves capillary pattern and hence can detect micro-vessel morphological changes of early neoplasia to target biopsies and aid in diagnosis. The clinical significance increased after the advent of endoscopic treatment modalities like ESD/EMR which requires precise delineation of extent and depth of lesion. Most of the studies have used narrow-band imaging (NBI) (Olympus Medical Systems Tokyo, Japan), although data from i-SCAN (PENTAX Endoscopy, Tokyo, Japan) and flexible spectral imaging color enhancement (FICE) (Fujinon, Fujifilm Medical Co, Saitama, Japan) are emerging. Electronic chromo-endoscopy is convenient compared to dye-based chromo-endoscopy in the sense that it is available at the push of a button in endoscope and reduces procedure time substantially with comparable efficacy. Scope of this review is to discuss available electronic chromo-endoscopy modalities and their role in the diagnosis, surveillance, and management of early GI neoplasia.

THE IMPACT OF COLORECTAL CHROMENDOSCOPY WITH ENHANCED MUCOSAL IMAGING ON ADENOMA MISS RATE IN SCREENING COLONOSCOPY

BACKGROUND

Colonoscopy is the gold standard for the diagnosis and treatment of adenomas. It is related with decreased colorectal cancer incidence and mortality. However, an important problem is missed colorectal adenoma. All efforts should be undertaken to reduce this rate. Enhancing imaging technologies including electronic chromoendoscopy and magnification has been increasingly adopted for improving the colorectal neoplasia detection rate and the detailed study of its surface, as well. I-scan images (Pentax, Tokyo, Japan) provides virtual chromoendoscopy in real-time during the examination to view the surface pattern, highlighting the microvasculature of the neoplastic lesion. The evidence on the impact of the use of I-scan on the colorectal adenoma detection rate is scarce.

OBJECTIVE

To evaluate whether the use of I-scan has impact on the adenoma miss rate (AMR) of screening colonoscopy exams.

METHODS

Observational and prospective study conducted by monitoring patients over 50 years undergoing colonoscopy. There were two groups: Group 1 - first inspection with standard high-definition white-light (HDWL) followed by a second inspection with I-scan 1; Group 2 - first inspection with I-scan 1 followed by a second inspection with standard HDWL. The primary outcome was the AMR from the first exam, calculated with the number of adenomas detected in the second exam, divided by the total number of adenomas detected in both exams.

RESULTS

A total of 85 patients participated in the study. 14 were excluded, with a final sample of 71 patients, in the Group 1, 34 patients, and the Group 2, 37. A total of 58 adenomas were detected, 40 in the first inspection (20 in each group) and 18 in the second inspection in group 1. The overall AMR was higher for the Group 1 than the Group 2 (47.4% vs 0% P=0.0002).

CONCLUSION

The use of I-scan 1 during colonoscopy exam reduces the AMR.

Enhancing polyp detection: technological advances in colonoscopy imaging

The detection and removal of polyps at colonoscopy is core to the current colorectal cancer (CRC) prevention strategy. However, colonoscopy is flawed with a well described miss rate and variability in detection rates associated with incomplete protection from CRC. Consequently, there is significant interest in techniques and technologies which increase polyp detection with the aim to remedy colonoscopy's ills. Technologic advances in colonoscope imaging are numerous and include; increased definition of imaging, widening field of view, virtual technologies to supplant conventional chromocolonoscopy (CC) and now computer assisted detection. However, despite nearly two decades of technologic advances, data on gains in detection from individual technologies have been modest at best and heterogenous and conflicted as a rule. This state of detection technology science is exacerbated by use of relatively blunt metrics of improvement without consensus, the myopic search for gains over single generations of technology improvement and an unhealthy focus on adenomatous lesions. Yet there remains cause for optimism as detection gains from new technology, while small, may still improve CRC prevention. The technologies are also readily available in current generation colonoscopes and have roles beyond simply detection such as lesion characterization, further improving their worth. Coupled with the imminent expansion of computer assisted detection the detection future from colonoscope imaging advances looks bright. This review aims to cover the major imaging advances and evidence for improvement in polyp detection.

Cold versus hot polypectomy/endoscopic mucosal resection-A review of current evidence

Background

Colonoscopy with polypectomy substantially reduces the risk of colorectal cancer (CRC) but interval cancers still account for 9% of all CRCs, some of which are due to incomplete resection.

Aim

The aim of this review is to compare the outcomes of cold and hot endoscopic resection and provide technical tips and tricks for optimizing cold snare polypectomy.

Results

Cold snare polypectomy (CSP) is the standard technique for small (≤10 mm) colorectal polyps. For large colonic polyps (>10 mm), hot resection techniques with use of electrocautery (polypectomy or endoscopic mucosal resection) were recommended until recently. However, the use of electrocoagulation brings serious adverse effects in up to 9% of the patients, such as delayed bleeding, post‐polypectomy syndrome and perforation. In recent years, efforts have been made to improve the polypectomy with cold snare in order to avoid these adverse effects of electrocoagulation without compromising the efficacy of the resection. Several authors have recently shown that the complication rates of CSP of polyps >10 mm is close to zero and recurrence rates varies between 5‐18%. Lower recurrence rates are found in serrated lesions (<8%).

[Position paper on endoscopic reporting in IBD]

The complete and reliable documentation of endoscopic findings make up the crucial foundation for the treatment of patients with inflammatory bowel diseases such as Crohn´s disease and ulcerative colitis. These findings are, on the one hand, a prerequisite for therapeutic decisions and, on the other hand, important as a tool for assessing the response to ongoing treatments. Endoscopic reports should, therefore, be recorded according to standardized criteria to ensure that the findings of different endoscopists can be adequately compared and that changes in the course of the disease can be traced back. In consideration of these necessities, fifteen members of the Imaging Working Group of the German Kompetenznetz Darmerkrankungen have created a position paper proposing a structure and specifications for the documentation of endoscopic exams. In addition to the formal report structure, the recommendations address a large number of attributes of acute and chronic inflammatory alterations as well as endoscopically detectable complications, which are explained in detail and illustrated using exemplary images. In addition, more frequently used endoscopic activity indices are presented and their use in everyday clinical practice is discussed.

Outcomes of colonoscopy with non-anesthesiologist-administered propofol (NAAP): an equivalence trial

Background and study aims  Efficacy and safety of NAAP for gastrointestinal endoscopy have been widely documented, although there is no information about the outcomes of colonoscopy when the endoscopist supervises the sedation. In this context, the aim of this trial was to determine the equivalence of adenoma detection rate (ADR) in colorectal cancer (CRC) screening colonoscopies performed with non-anesthesiologist-administered propofol (NAAP) and performed with monitored anesthesia care (MAC). Patients and methods  This was a single-blind, non-randomized controlled equivalence trial that enrolled adults from a national CRC screening program (CRCSP). Patients were blindly assigned to undergo either colonoscopy with NAAP or MAC. The main outcome measure was the ADR in CRCSP colonoscopies performed with NAAP. Results  We included 315 patients per group. The median age was 59.76 ± 5.81 years; 40.5 % of patients were women. The cecal intubation rate was 97 %, 81.8 % of patients had adequate bowel preparation, withdrawal time was > 6 minutes in 98.7 %, and the median global exploration time was 24.25 ± 8.86 minutes (range, 8-70 minutes). The ADR was 62.9 % and the complication rate (CR) was 0.6 %. Analysis by intention-to-treat showed an ADR in the NAAP group of 64.13 % compared with 61.59 % in the MAC group, a difference (δADR) of 2.54 %, 95 %CI: -0.10 to 0.05. Analysis by per-protocol showed an ADR in the NAAP group of 62.98 %, compared with 61.94 % in the MAC group, δADR: 1.04 %, 95 %CI: -0.09 to 0.07. There was no difference in CR (NAAP: 0,63 vs. MAC: 0.63); P  = 1.0. Conclusions  ADR in colorectal cancer screening colonoscopies performed with NAAP was equivalent to that in those performed with MAC. Similarly, there was no difference in complication rates.

European guidelines from the EHTG and ESCP for Lynch syndrome: an updated third edition of the Mallorca guidelines based on gene and gender

BACKGROUND

Lynch syndrome is the most common genetic predisposition for hereditary cancer but remains underdiagnosed. Large prospective observational studies have recently increased understanding of the effectiveness of colonoscopic surveillance and the heterogeneity of cancer risk between genotypes. The need for gene- and gender-specific guidelines has been acknowledged.

METHODS

The European Hereditary Tumour Group (EHTG) and European Society of Coloproctology (ESCP) developed a multidisciplinary working group consisting of surgeons, clinical and molecular geneticists, pathologists, epidemiologists, gastroenterologists, and patient representation to conduct a graded evidence review. The previous Mallorca guideline format was used to revise the clinical guidance. Consensus for the guidance statements was acquired by three Delphi voting rounds.

RESULTS

Recommendations for clinical and molecular identification of Lynch syndrome, surgical and endoscopic management of Lynch syndrome-associated colorectal cancer, and preventive measures for cancer were produced. The emphasis was on surgical and gastroenterological aspects of the cancer spectrum. Manchester consensus guidelines for gynaecological management were endorsed. Executive and layperson summaries were provided.

CONCLUSION

The recommendations from the EHTG and ESCP for identification of patients with Lynch syndrome, colorectal surveillance, surgical management of colorectal cancer, lifestyle and chemoprevention in Lynch syndrome that reached a consensus (at least 80 per cent) are presented.

Does anti-tumor necrosis factor alpha prevent the recurrence of Crohn's disease? Systematic review and meta-analysis

BACKGROUND AND AIM

Anti-tumor necrosis factor (TNF) α agents are now well known to function as effective treatments for Crohn's disease (CD). Several meta-analyses have revealed the efficacy of anti-TNF therapy for preventing recurrence after surgery; however, the efficacies reported in some prospective studies differed according to the outcomes. Moreover, adverse events (AEs) were not well evaluated. We conducted this systematic review and meta-analysis to evaluate both the efficacy of anti-TNF therapy after stratification by the outcome of interest and the AEs.

METHODS

We performed a systematic literature review of studies investigating anti-TNF therapy, CD, and postoperative recurrence. Meta-analyses were performed for endoscopic and clinical recurrence and AEs.

RESULTS

A total of 570 participants, including 254 patients in the intervention group and 316 patients in the control group, in eight studies, were analyzed for recurrence. Based on the results of the meta-analysis, the efficacies of anti-TNF therapy at preventing endoscopic and clinical recurrence were as follows: relative risk (RR) 0.34, 95% confidence interval (CI) 0.22-0.53 and RR 0.60, 95% CI 0.36-1.02, respectively. The RR of AEs with anti-TNF therapy was 1.75 (95% CI 0.81-3.79).

CONCLUSIONS

Anti-TNF therapy after surgery for CD displays efficacy at preventing endoscopic recurrence for 1-2 years, without increasing the incidence of AEs. However, clinical recurrence was not significantly reduced. The efficacy of postoperative anti-TNF therapy may differ in terms of the outcomes, which include long-term prevention, the avoidance of further surgery, and cost-effectiveness.

Optical diagnosis of colorectal polyps: a randomized controlled trial comparing endoscopic image-enhancing modalities

BACKGROUND AND AIMS

Optical polyp diagnosis using image-enhanced endoscopy (IEE) allows for real-time histology prediction of colorectal polyps. The aim of this study was to evaluate a recently introduced IEE modality (Optivista [OV]; Pentax Medical, Tokyo, Japan) in a randomized controlled trial.

METHODS

In a prospective cohort of subjects (ages 45-80 years) undergoing elective screening, surveillance, or diagnostic colonoscopy, all colorectal polyps between 1 and 5 mm underwent IEE assessment. Study subjects were randomized before their colonoscopy procedure to undergo optical polyp diagnosis using either OV IEE or iScan (IS) IEE. A validated IEE scale (NBI International Colorectal Endoscopic classification) was used for optical polyp diagnosis. The primary outcome was the agreement of surveillance intervals determined when using OV IEE compared with IS IEE in reference with pathology-based surveillance intervals. Secondary outcomes were the percentage of surveillance intervals that could be given on the same day as the procedure, percentage of pathology tests avoided, diagnostic performance, and negative predictive value (NPV) of optical diagnosis for rectosigmoid adenomas.

RESULTS

Four hundred ten patients were enrolled in the trial. The polyp detection rate was 58.6%, and the adenoma detection rate was 38.8%. The proportion of correct surveillance interval assignment when using OV or IS IEE was 96.5% versus 96.0% (P = .75). A total of 65.1% of patients could be given same-day surveillance intervals when using OV IEE versus 73.1% for IS IEE (P = .07). The NPV for rectosigmoid adenomas (including sessile serrated adenomas) was 97.5% when using OV IEE and 88.2% when using IS IEE. Using high-confidence optical diagnosis instead of pathology would have resulted in a 44.3% elimination of required pathology examinations for OV IEE versus 52.8% for IS IEE (P = .34).

CONCLUSIONS

Optical diagnosis using OV and IS IEE both surpassed the 90% benchmark of surveillance interval assignment, and no significant difference with regard to correct surveillance interval assignment was found. OV IEE surpassed the ≥90% NPV for rectosigmoid adenomas, whereas IS IEE did not. (Clinical trial registration number: NCT03515343.).

Intestinal cancer in patients with Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Although surveillance colonoscopy is recommended by several guidelines for Crohn's disease (CD), the evidence is insufficient to support the validity of this recommendation. Moreover, the efficacy of surveillance colonoscopy for anorectal cancer remains unclear. Therefore, we performed a systematic review of cancer in patients with CD before considering the proper surveillance methods.

METHODS

We conducted a systematic review and meta-analysis examining the incidence of intestinal cancer and a literature review to clarify the characteristic features of cancer in CD. We performed the systematic literature review of studies published up to May 2019.

RESULTS

Overall, 7344 patients were included in eight studies. The standardized incidence ratios (95% confidence intervals) of colorectal cancer (CRC) and small bowel cancer (SBC) were 2.08 (1.43-3.02) and 22.01 (9.10-53.25), respectively. The prevalence of CRC and SBC was 57/7344 (0.77%) and 17/7344 (0.23%), respectively, during a median follow-up of 12.55 years. Additionally, 54 studies reporting 208 anorectal cancer cases were identified. In patients with anorectal cancer, the prognosis for survival was 2.1 ± 2.3 years, and advanced cancer greater than stage T3 occurred in 46/74 patients (62.1%). Many more reports of anorectal cancer were published in Asia than in Western countries.

CONCLUSION

Although we were unable to state a recommendation for surveillance for SBC, we should perform cancer surveillance for CRC in patients with CD. However, the characteristics of cancer may differ according to geography or race. We must establish proper and effective surveillance methods that are independently suitable to detect these differences.

Colorectal polyp characterization with endocytoscopy: Ready for widespread implementation with artificial intelligence?

Endocytoscopy provides an in-vivo visualization of nuclei and micro-vessels at the cellular level in real-time, facilitating so-called "optical biopsy" or "virtual histology" of colorectal polyps/neoplasms. This functionality is enabled by 520-fold magnification power with endocytoscopy and recent breakthroughs in artificial intelligence (AI) allowing a great advance in endocytoscopic imaging; interpretation of images is now fully supported by AI tool which outputs predictions of polyp histopathology during colonoscopy. The advantage of the use of AI during optical biopsy can be appreciated especially by non-expert endoscopists who to increase performance. This paper provides an overview of the latest evidence on colorectal polyp characterization with endocytoscopy combined with AI and identify the barriers to its widespread implementation.

Efficacy of repeat forward-view examination of the right-sided colon during colonoscopy: A prospective randomized controlled trial

BACKGROUND AND AIM

Generally, colonoscopy is less effective for detecting colorectal adenomas in the right-sided colon compared with the distal colon. Repeat forward-view (RF) examination of the right-sided colon has been suggested to increase the adenoma detection rate (ADR). However, studies investigating the efficacy of RF examination are lacking. Thus, the aim of this study was to determine whether RF examination in the right-sided colon enhances right-sided ADR.

METHODS

We performed a prospective, randomized controlled trial, including asymptomatic subjects who underwent screening colonoscopy. Subjects were randomized to the RF group, in which the right-sided colon was examined twice in the forward view, or to the standard forward-view (SF) group, in which the right-sided colon was examined once in the forward view. The primary outcome was the right-sided ADR on RF examination of the right-sided colon.

RESULTS

A total of 640 subjects completed the study protocol (RF group, n = 320; SF group, n = 320). The right-sided ADR in the RF group was significantly higher than that in the SF group (17.5% vs 11.9%, respectively; P = 0.044). In the RF group, an additional 31 adenomas were found, resulting in an increased detection rate of adenomas of 38.3% compared with the first forward view. The ADR of the whole colon was similar between the groups.

CONCLUSIONS

In our prospective randomized controlled trial, RF examination of the right-sided colon, which can be easily performed in clinical practice, was associated with an increased rate of detection of right-sided ADR.

Are adenoma and serrated polyp detection rates correlated with endoscopists' sensitivity of optical diagnosis?

INTRODUCTION : Endoscopists with a high adenoma detection rate (ADR) and proximal serrated polyp detection rate (PSPDR) detect these polyps more frequently, which may be attributable to better recognition of their endoscopic features. Little is known about the association between endoscopic lesion detection and differentiation skills. Therefore, we evaluated the correlation between the ADR, PSPDR, and the sensitivity of optical diagnosis for adenomas and serrated polyps.

METHODS

We performed an exploratory post-hoc analysis of the DISCOUNT-2 study, including complete colonoscopies after a positive fecal immunochemical test (FIT) performed by endoscopists who performed ≥ 50 colonoscopies. The correlations between the ADR, PSPDR, and the sensitivity of optical diagnosis were calculated using Pearson's rho correlation coefficient.

RESULTS

24 endoscopists performed ≥ 50 colonoscopies, resulting in a total of 2889 colonoscopies. The overall ADR was 84.5 % (range 71.4 % - 95.3 %) and overall PSPDR was 13.7 % (4.3 % - 29.0 %). The sensitivity of optical diagnosis for adenomas and serrated polyps were 94.5 % (83.3 % - 100 %) and 74.0 % (37.5 % - 94.1 %), respectively. No correlation could be demonstrated between the ADR and the sensitivity of optical diagnosis for adenomas (-0.20; P = 0.35) or between the PSPDR and the sensitivity of optical diagnosis for serrated polyps (-0.12; P = 0.57).

CONCLUSIONS

In a homogeneous FIT-positive population, no correlation between the ADR, PSPDR, and the sensitivity of optical diagnosis for adenomas and serrated polyps could be demonstrated. These exploratory results suggest that lesion detection and differentiation require different endoscopic skills. Further prospective studies are needed; until then, monitoring of both performance indicators is important to secure optimal efficacy of FIT-based colorectal cancer screening.

Clinical Validation of BASIC Classification for the Resect and Discard Strategy for Diminutive Colorectal Polyps

BACKGROUND & AIMS

Blue-light imaging (BLI) is a chromoendoscopy technique that uses direct (not filtered) emission of blue light with short wavelength (410 nm) to increase visibility of microvascular pattern and superficial mucosa. A BLI-based classification system for colorectal polyps (also called BLI Adenomas Serrated International Classification, BASIC) has been created and was validated using still images or short videos. We aimed to validate BASIC in a clinical practice setting, using thresholds recommended by the American Society for Gastrointestinal Endoscopy for the resect and discard strategy as the reference standard.

METHODS

We studied 333 patients (mean age, 62.7±8.1 y; 176 men) who underwent screening colonoscopy from January through July 2019. Six endoscopists trained in BASIC participated in the study. All detected diminutive polyps were characterized by real-time BLI and categorized as adenoma or non-adenoma according to BASIC. All polyps were removed and evaluated by histopathology. The BLI-directed surveillance intervals (based on high-confidence characterization of polyps 5 mm or smaller and pathology feature for others) were compared with histology-directed surveillance intervals, according to United States Multi-society Task Force and European Society of Gastrointestinal Endoscopy recommendations. We calculated negative-predictive values of optical real-time analysis of diminutive rectosigmoid adenomas.

RESULTS

When we applied BASIC, 748 polyps smaller than 5 mm were categorized with 89% accuracy (95% CI, 85.9%-90.6%). BLI-directed surveillance was correct for 90% of patients according to the United States Multi-society task force criteria (95% CI, 86%-93%) and for 96% of patients according to European Society of Gastrointestinal Endoscopy criteria (95% CI, 93%-97%). The negative-predictive value for 302 polyps smaller than 5 mm, located in the rectosigmoid colon and evaluated with high confidence, based on histologic features of adenomatous polyps, was 91% (95% CI, 85%-95%).

CONCLUSIONS

Our analysis of data from 333 patients undergoing screen colonoscopies supports the validity of BASIC discriminating diminutive colorectal polyps with histologic features of adenomas from non-adenomas. This allows for the implementation of the resect and discard strategy based on BLI in clinical practice. ClinicalTrials.gov no: NCT03746171.

Deep learning to find colorectal polyps in colonoscopy: A systematic literature review

Colorectal cancer has a great incidence rate worldwide, but its early detection significantly increases the survival rate. Colonoscopy is the gold standard procedure for diagnosis and removal of colorectal lesions with potential to evolve into cancer and computer-aided detection systems can help gastroenterologists to increase the adenoma detection rate, one of the main indicators for colonoscopy quality and predictor for colorectal cancer prevention. The recent success of deep learning approaches in computer vision has also reached this field and has boosted the number of proposed methods for polyp detection, localization and segmentation. Through a systematic search, 35 works have been retrieved. The current systematic review provides an analysis of these methods, stating advantages and disadvantages for the different categories used; comments seven publicly available datasets of colonoscopy images; analyses the metrics used for reporting and identifies future challenges and recommendations. Convolutional neural networks are the most used architecture together with an important presence of data augmentation strategies, mainly based on image transformations and the use of patches. End-to-end methods are preferred over hybrid methods, with a rising tendency. As for detection and localization tasks, the most used metric for reporting is the recall, while Intersection over Union is highly used in segmentation. One of the major concerns is the difficulty for a fair comparison and reproducibility of methods. Even despite the organization of challenges, there is still a need for a common validation framework based on a large, annotated and publicly available database, which also includes the most convenient metrics to report results. Finally, it is also important to highlight that efforts should be focused in the future on proving the clinical value of the deep learning based methods, by increasing the adenoma detection rate.

Value of endoscopy with narrow-band imaging and probe-based confocal laser endomicroscopy in the diagnosis of preneoplastic lesions of gastrointestinal tract

INTRODUCTION

Amongst all malignant tumors, cancers of the digestive tract rank first in terms of yearly deaths. Patients above 60 years of age are the most affected, as the diagnosis is frequently made in advanced stages of the disease when therapy is less effective. Our study aimed to evaluate the efficiency of narrow-band imaging (NBI) endoscopy and probe-based confocal laser endomicroscopy (pCLE) in the correct diagnosis of preneoplastic lesions in the upper and lower digestive tract.

PATIENTS, MATERIALS AND METHODS

We included 46 patients with digestive preneoplastic lesions, who underwent either upper or lower digestive endoscopy, followed by NBI and pCLE. We recorded 5-10 frames per each lesion, from different angles and distances during white-light endoscopy and selected frames from full recordings of NBI and pCLE. Usual preparation was used for the endoscopic procedures; pCLE required in vivo administration of 10% Sodium Fluorescein as a contrast agent. Pathology was performed in case of solid tumors. Three medical professionals with different levels of training, blinded to the results, interpreted the data.

RESULTS

The experienced physician correlated very well the NBI findings with pathology (0.93, p=0.05), while the resident physician and the experienced nurse obtain lower, albeit still statistically significant, values (0.73 and 0.62, respectively). For pCLE, the experienced physician obtained near-perfect correlation with pathology (0.96), followed closely by the resident physician (0.93). The nurse obtained a modest correlation (0.42). All examiners obtained approximately equal performances in discerning between malignant and benign lesions.

CONCLUSIONS

Digestive endoscopy in NBI mode proved its effectiveness. Even less experienced endoscopists can achieve good results, while an experienced nurse can positively influence the diagnosis. In the case of pCLE, when available, it can greatly reduce diagnostic times, while requiring higher expertise and specialty training.

Improved adenoma detection with linked color imaging technology compared to white-light colonoscopy

OBJECTIVES

Linked color imaging (LCI) is a new endoscopic technology that may increase colorectal adenoma detection rate (ADR) and polyp detection rate (PDR) by virtual chromoendoscopy. Aim of the present study was to evaluate the effectiveness of LCI in ADR and PDR compared to the HD white-light colonoscopy (WLC) technique.

MATERIALS AND METHODS

Between October 2016 and June 2018, we enrolled consecutive outpatients prospectively. Eligible patients allocated randomly to undergo HD WLC or LCI colonoscopy technique during instrument withdrawal. Each colonoscopy was performed in a single center by the same three expert endoscopists (with expertise more than 5000 colonoscopies).

RESULTS

A total of 1278 patients underwent colonoscopy in the study period. ADR and PDR were significantly higher in the LCI group compared to the WLC group (34.4% vs. 26.8%; p = .007; and 53.3% vs 46.4%; p = .023, respectively). Similarly, the mean number of adenomas per patient (MAP) was significantly higher with the LCI than WLC (0.64 vs 0.44, respectively; p = .002). The mean age of patients at the time of colonoscopy was 51.95 years (SD = 13.861) in the LCI group and 51.96 years (SD = 14.028) in the WLC group. No significant differences observed in patient demographic characteristics (there was no difference in gender and age distribution, p = .986), quality of colonoscopy preparation and withdrawal times (WT) between the two groups (WLC and the LCI groups, 493.9 (SD: 143.5) and 514.0 (SD: 139.5) sec, respectively).

CONCLUSIONS

According to our results, LCI virtual chromoendoscopic technology was superior compared to conventional HD WLC in detecting colorectal polyps and adenomas.

Artificial Intelligence-assisted System Improves Endoscopic Identification of Colorectal Neoplasms

BACKGROUND & AIMS

Precise optical diagnosis of colorectal polyps could improve the cost-effectiveness of colonoscopy and reduce polypectomy-related complications. However, it is difficult for community-based non-experts to obtain sufficient diagnostic performance. Artificial intelligence-based systems have been developed to analyze endoscopic images; they identify neoplasms with high accuracy and low interobserver variation. We performed a multi-center study to determine the diagnostic accuracy of EndoBRAIN, an artificial intelligence-based system that analyzes cell nuclei, crypt structure, and microvessels in endoscopic images, in identification of colon neoplasms.

METHODS

The EndoBRAIN system was initially trained using 69,142 endocytoscopic images, taken at 520-fold magnification, from patients with colorectal polyps who underwent endoscopy at 5 academic centers in Japan from October 2017 through March 2018. We performed a retrospective comparative analysis of the diagnostic performance of EndoBRAIN vs that of 30 endoscopists (20 trainees and 10 experts); the endoscopists assessed images from 100 cases produced via white-light microscopy, endocytoscopy with methylene blue staining, and endocytoscopy with narrow-band imaging. EndoBRAIN was used to assess endocytoscopic, but not white-light, images. The primary outcome was the accuracy of EndoBrain in distinguishing neoplasms from non-neoplasms, compared with that of endoscopists, using findings from pathology analysis as the reference standard.

RESULTS

In analysis of stained endocytoscopic images, EndoBRAIN identified colon lesions with 96.9% sensitivity (95% CI, 95.8%-97.8%), 100% specificity (95% CI, 99.6%-100%), 98% accuracy (95% CI, 97.3%-98.6%), a 100% positive-predictive value (95% CI, 99.8%-100%), and a 94.6% negative-predictive (95% CI, 92.7%-96.1%); these values were all significantly greater than those of the endoscopy trainees and experts. In analysis of narrow-band images, EndoBRAIN distinguished neoplastic from non-neoplastic lesions with 96.9% sensitivity (95% CI, 95.8-97.8), 94.3% specificity (95% CI, 92.3-95.9), 96.0% accuracy (95% CI, 95.1-96.8), a 96.9% positive-predictive value, (95% CI, 95.8-97.8), and a 94.3% negative-predictive value (95% CI, 92.3-95.9); these values were all significantly higher than those of the endoscopy trainees, sensitivity and negative-predictive value were significantly higher but the other values are comparable to those of the experts.

CONCLUSIONS

EndoBRAIN accurately differentiated neoplastic from non-neoplastic lesions in stained endocytoscopic images and endocytoscopic narrow-band images, when pathology findings were used as the standard. This technology has been authorized for clinical use by the Japanese regulatory agency and should be used in endoscopic evaluation of small polyps more widespread clinical settings. UMIN clinical trial no: UMIN000028843.

High-definition colonoscopy for improving adenoma detection: a systematic review and meta-analysis of randomized controlled studies

BACKGROUND AND AIMS

Previous meta-analysis showed marginal benefit of high-definition white-light endoscopy (HD-WLE) over standard-definition colonoscopy (SDC) for adenoma detection, but with residual uncertainty due to inclusion of nonrandomized studies. We aimed to further assess the effect of HD-WLE on adenoma detection by including only randomized controlled trials (RCTs).

METHODS

A literature search was performed for RCTs evaluating HD-WLE versus SDC in terms of adenoma, advanced adenoma, and serrated sessile adenoma detection rates as well as the mean number of adenomas per colonoscopy (MAC), the mean number of advanced adenomas per colonoscopy (MAAC), and the mean number of sessile serrated adenomas per colonoscopy (MSSAC). The effect size on study outcomes is presented as the risk ratio (RR; 95% confidence interval [CI]) or mean difference (MD; 95% CI). We assessed the strength of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Six RCTs involving 4594 individuals (HD-WLE, 2323; SDC, 2271) were included. Clinical indications were screening (1 study), positive result for fecal occult blood test, personal/family history of colorectal cancer (1 study), and mixed indications (4 studies). Withdrawal time was similar between the 2 arms (MD, -0.06; 95% CI, -0.25 to 0.12; P = .50). The adenoma detection rate was significantly higher in the HD-WLE arm compared with the SDC arm (40% vs 35%; RR, 1.13; 95% CI, 1.05-1.22; P = .001; I² = 0%; GRADE, low). This effect was consistent for advanced and sessile serrated adenoma detection rates (RR, 1.33; 95% CI, 1.03-1.72; P = .03; I² = 0%; GRADE, low; and RR, 1.55; 95% CI, 1.05-2.28; P = .03; I² = 0%; GRADE, low, respectively). In contrast, the difference was not significant for MAC, MAAC, and MSSAC.

CONCLUSIONS

Meta-analyses of RCT data support the use of HD-WLE in clinical practice, although the additional benefit is limited.

Surveillance in inflammatory bowel disease: is chromoendoscopy the only way to go? A systematic review and meta-analysis of randomized clinical trials

Background and study aims  Ulcerative colitis (UC) and Crohn's disease (CD) have higher risk of colorectal cancer (CRC). Guidelines recommend dysplasia surveillance with dye-spraying chromoendoscopy (DCE). The aim of this systematic review and meta-analysis was to review all randomized clinical trials (RCTs) available and compare the efficacy of different endoscopic methods of surveillance for dysplasia in patients with UC and CD. Methods  Databases searched were Medline, EMBASE, Cochrane and SCIELO/LILACS. It was estimated the risk difference (RD) for dichotomous outcomes (number of patients diagnosed with one or more dysplastic lesions, total number of dysplastic lesions diagnosed and number of dysplastic lesions detected by targeted biopsies) and mean difference for continuous outcomes (procedure time). Results  This study included 17 RCTs totaling 2,457 patients. There was superiority of DCE when compared to standard-definiton white light endoscopy (SD-WLE). When compared with high-definition (HD) WLE, no difference was observed in all outcomes (number of patients with dysplasia (RD 0.06; 95 % CI [-0.01, 0.13])). Comparing other techniques, no difference was observed between DCE and virtual chromoendoscopy (VCE - including narrow-band imaging [NBI], i-SCAN and flexible spectral imaging color enhancement), in all outcomes except procedure time (mean difference, 6.33 min; 95 % CI, 1.29, 11.33). DCE required a significantly longer procedure time compared with WLE (mean difference, 7.81 min; 95 % CI, 2.76, 12.86). Conclusions  We found that dye-spraying chromoendoscopy detected more patients and dysplastic lesions than SD-WLE. Although no difference was observed between DCE and HD-WLE or narrow-band imaging, the main outcomes favored numerically dye-spraying chromoendoscopy, except procedure time. Regarding i-SCAN, FICE and auto-fluorescence imaging, there is still not enough evidence to support or not their recommendation.

Uptake and barriers for implementation of the resect and discard strategy: an international survey

Background and study aims  Optical real-time diagnosis (= resect-and-discard strategy) is an alternative to histopathology for diminutive colorectal polyps. However, clinical adoption of this approach seems sparse. We were interested in evaluating potential clinical uptake and barriers for implementation of this approach. Methods  We conducted an international survey using the "Google forms" platform. Nine endoscopy societies distributed the survey. Survey questions measured current clinical uptake and barriers for implementing the resect-and-discard strategy , perceived cancer risk associated with diminutive polyps and potential concerns with using CT-colonography as follow-up, as well as non-resection of diminutive polyps. Results  Eight hundred and eight endoscopists participated in the survey. 84.2 % (95 % CI 81.6 %-86.7 %) of endoscopists are currently not using the resect-and-discard strategy and 59.9 % (95 % CI 56.5 %-63.2 %) do not believe that the resect-and-discard strategy is feasible for implementation in its current form. European (38.5 %) and Asian (45 %) endoscopists had the highest rates of resect-and-discard practice, while Canadian (13.8 %) and American (5.1 %) endoscopists had some of the lowest implementation rates. 80.3 % (95 % CI 77.5 %-83.0 %) of endoscopists believe that using the resect-and-discard strategy for diminutive polyps will not increase cancer risk. 48.4 % (95 % CI 45.0 %-51.9 %) of endoscopists believe that leaving diminutive polyps in place is associated with increased cancer risk. This proportion was slightly higher (54.7 %; 95 % CI 53.6 %-60.4 %) when asked if current CT-colonography screening practice might increase cancer risks. Conclusion  Clinical uptake of resect-and-discard is very low. Most endoscopists believe that resect-and-discard is not feasible for clinical implementation in its current form. The most important barriers for implementation are fear of making an incorrect diagnosis, assigning incorrect surveillance intervals and medico-legal consequences.

Narrow-band imaging and high-definition white-light endoscopy in patients with serrated lesions not fulfilling criteria for serrated polyposis syndrome: a randomized controlled trial with tandem colonoscopy

BACKGROUND

It is unknown whether narrow-band imaging (NBI) could be more effective than high-definition white-light endoscopy (HD-WLE) in detecting serrated lesions in patients with prior serrated lesions > 5 mm not completely fulfilling serrated polyposis syndrome (SPS) criteria.

METHODS

We conducted a randomized, cross-over trial in consecutive patients with prior detection of at least one serrated polyp ≥10 mm or ≥ 3 serrated polyps larger than 5 mm, both proximal to the sigmoid colon. Five experienced endoscopists performed same-day tandem colonoscopies, with the order being randomized 1:1 to NBI-HD-WLE or HD-WLE-NBI. All tandem colonoscopies were performed by the same endoscopist.

RESULTS

We included 41 patients. Baseline characteristics were similar in the two cohorts: NBI-HD-WLE (n = 21) and HD-WLE-NBI (n = 20). No differences were observed in the serrated lesion detection rate of NBI versus HD-WLE: 47.4% versus 51.9% (OR 0.84, 95% CI: 0.37-1.91) for the first and second withdrawal, respectively. Equally, no differences were found in the polyp miss rate of NBI versus HD-WLE: 21.3% versus 26.1% (OR 0.77, 95% CI: 0.43-1.38). Follow-up colonoscopy in nine patients (22%) allowed them to be reclassified as having SPS.

CONCLUSIONS

In patients with previous serrated lesions, the serrated lesion detection rate was similar with NBI and HD-WLE. A shorter surveillance colonoscopy interval increases the detection of missed serrated polyps and could change the diagnosis of SPS in approximately one in every five patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02406547, registered on April 2, 2015.

Magnification endoscopy in combination with acetic acid enhancement and narrow-band imaging for the accurate diagnosis of colonic neoplasms

Background and study aims  Magnification endoscopy with narrow-band imaging (NBIME) and NBIME with acetic acid enhancement (A-NBIME) enable visualization of the vascular and microstructural patterns of colorectal polyp. We compared the diagnostic accuracy and reproducibility of white light endoscopy (WLE), NBIME, and A-NBIME for predictive histologic diagnosis. Patients and methods  Consecutive colorectal polyps (N = 628; 38 hyperplasias, 488 adenomas, 72 M-SM1 cancers, and 30 SM2 cancers) were photographed with WLE, NBIME, and A-NBIME. Endoscopic images were independently reviewed by three experts, according to the traditional criteria for WLE, the Japan NBI Expert Team classification for NBIME, and pit pattern classification for A-NBIME to compare diagnostic accuracy and interobserver diagnostic agreement among modalities. Results  The specificity (95 % confidence interval) of hyperplasia and SM2 cancer with WLE were 98.2 % (96.8 %-99.1%) and 99.4 % (98.5 %-99.9 %), respectively, showing high accuracy for endoscopic resection without magnifying observation. Diagnostic accuracy of WLE, NBIME, and A-NBIME was 80.8 % (77.4 %-83.8 %), 79.3 % (75.9 %-82.4 %), and 86.1 % (83.2 %-88.7 %), respectively, showing the highest accuracy for A-NBIME among modalities ( P  < .05). NBIME showed a lower PPV for M-SM1 cancer ( P  < .05), as with WLE ( P  = .08) compared to A-NBIME. Fleiss's kappa values for WLE, NBIME, and A-NBIME diagnosis were 0.43 (0.39 - 0.46), 0.52 (0.49 - 0.56) and 0.65 (0.62 - 0.69), respectively, showing insufficient reproducibility of WLE and superiority of A-NBIME among modalities. Conclusion  WLE showed high accuracy for endoscopic resection of colorectal polyps in expert diagnosis. NBIME demonstrated a higher diagnostic reproducibility than WLE. A-NBIME showed possible superiority among modalities in both diagnostic accuracy and reproducibility.

Cap-Assisted Chromoendoscopy Using a Mounted Cap Versus Standard Colonoscopy for Adenoma Detection

OBJECTIVES

Some neoplastic lesions remain undetected on colonoscopy. To date, no studies have investigated whether combining cap-assisted colonoscopy with chromoendoscopy increases the adenoma detection rate (ADR). This study aimed to compare cap-assisted chromoendoscopy (CAP/CHROMO) with standard colonoscopy (SC) with respect to their efficacy in detecting adenomas.

METHODS

This prospective, multicenter, randomized controlled trial included asymptomatic subjects aged 45-75 years who underwent colonoscopy for the first time at 14 university hospitals. Subjects were randomized to either the CAP/CHROMO group (with 0.09% indigo carmine spraying using a cap-mounted catheter at the tip of the colonoscope) or the SC group. All polyps were resected, but only histologically confirmed neoplastic lesions were considered for analysis. The primary outcome was ADR, defined as the proportion of subjects with at least 1 adenoma.

RESULTS

A total of 1,905 subjects were randomized to the CAP/CHROMO (n = 948) or SC (n = 957) group at 14 centers. Subjects' demographic characteristics were similar between both groups. The CAP/CHROMO group had significantly higher ADR than the SC group (54.4% vs 44.9%, P < 0.001). Significantly, more subjects with at least 1 proximal colon adenoma were identified by CAP/CHROMO (38.6%) than by SC (31.2%) (P = 0.001). The proximal serrated polyp detection rate by CAP/CHROMO was significantly higher in the female subgroup vs SC. However, advanced ADR was not different between the CAP/CHROMO and SC groups (9.3% vs 7.6%, P = 0.180).

DISCUSSION

CAP/CHROMO markedly improved the ADR and enhanced the detection of proximal adenoma. CAP/CHROMO is feasible for routine application and will allow for a more effective surveillance program.

Optical diagnosis of diminutive polyps in the Dutch Bowel Cancer Screening Program: Are we ready to start?

Background and study aims  Implementation of optical diagnosis of diminutive polyps may potentially increase the efficacy and cost-effectiveness of colonoscopies. To adopt such strategy in clinical practice, the Preservation and Incorporation of Valuable endoscopic Innovations (PIVI) thresholds provide the basis to be met: ≥ 90 % negative predictive value (NPV) for diagnosis of adenomatous histology and ≥ 90 % agreement on surveillance intervals. We evaluated this within the Dutch Bowel Cancer Screening Program (BCSP). Patients and methods  Endoscopic and histological data were collected from participants of the national bowel cancer screening program with an unfavorable fecal immunochemical test referred for colonoscopy between February 2014 and August 2015 at four endoscopy centers. The "resect and discard" scenario was studied, resecting diminutive polyps without histological evaluation. Agreement between optical diagnosis and histological diagnosis was measured for surveillance intervals according to Dutch, European and American post-polypectomy surveillance guideline. Results  Fifteen certified endoscopists participated in this study and included 3028 diminutive polyps. In 2,330 patients both optical and histological diagnosis were available. Optical diagnosis of diminutive polyps showed NPV of 84 % (95 % CI 80-87) for adenomatous histology in the rectosigmoid. Applying the 'resect and discard' strategy resulted in 90.6 %, 91.2 %, 90.9 % agreement on surveillance intervals for the Dutch, European and American guideline respectively. Conclusion  Our data representing current clinical practice in the Dutch BCSP practice on optical diagnosis of diminutive polyps showed that accuracy of predicting histology remains challenging, and risk of incorrect optical diagnosis is still significant. Therefore, it is too early to safely implement these strategies.

White-Light Endoscopy Is Adequate for Lynch Syndrome Surveillance in a Randomized and Noninferiority Study

BACKGROUND & AIMS

Dye-based pancolonic chromoendoscopy is recommended for colorectal cancer surveillance in patients with Lynch syndrome. However, there is scarce evidence to support its superiority to high-definition white-light endoscopy. We performed a prospective study assess whether in the hands of high detecting colonoscopists, high-definition, white-light endoscopy is noninferior to pancolonic chromoendoscopy for detection of adenomas in patients with Lynch syndrome.

METHODS

We conducted a parallel controlled study, from July 2016 through January 2018 at 14 centers in Spain of adults with pathogenic germline variants in mismatch repair genes (60% women; mean age, 47 ± 14 years) under surveillance. Patients were randomly assigned to groups that underwent high-definition white-light endoscopy (n = 128) or pancolonic chromoendoscopy (n = 128) evaluations by 24 colonoscopists who specialized in detection of colorectal lesions in high-risk patients for colorectal cancer. Adenoma detection rates (defined as the proportion of patients with at least 1 adenoma) were compared between groups, with a noninferiority margin (relative difference) of 15%.

RESULTS

We found an important overlap of confidence intervals (CIs) and no significant difference in adenoma detection rates by pancolonic chromoendoscopy (34.4%; 95% CI 26.4%-43.3%) vs white-light endoscopy (28.1%; 95% CI 21.1%-36.4%; P = .28). However, pancolonic chromoendoscopy detected serrated lesions in a significantly higher proportion of patients (37.5%; 95% CI 29.5-46.1) than white-light endoscopy (23.4%; 95% CI 16.9-31.4; P = .01). However, there were no significant differences between groups in proportions of patients found to have serrated lesions of 5 mm or larger (9.4% vs 7.0%; P = .49), of proximal location (11.7% vs 10.2%; P = .68), or sessile serrated lesions (3.9% vs 5.5%; P = .55), respectively. Total procedure and withdrawal times with pancolonic chromoendoscopy (30.7 ± 12.8 minutes and 18.3 ± 7.6 minutes, respectively) were significantly longer than with white-light endoscopy (22.4 ± 8.7 minutes and 13.5 ± 5.6 minutes; P < .001).

CONCLUSIONS

In a randomized parallel trial, we found that for Lynch syndrome surveillance, high-definition white-light endoscopy is not inferior to pancolonic chromoendoscopy if performed by experienced and dedicated endoscopists. ClinicalTrials.gov no: NCT02951390.

Guidelines for the management of hereditary colorectal cancer from the British Society of Gastroenterology (BSG)/Association of Coloproctology of Great Britain and Ireland (ACPGBI)/United Kingdom Cancer Genetics Group (UKCGG)

Heritable factors account for approximately 35% of colorectal cancer (CRC) risk, and almost 30% of the population in the UK have a family history of CRC. The quantification of an individual's lifetime risk of gastrointestinal cancer may incorporate clinical and molecular data, and depends on accurate phenotypic assessment and genetic diagnosis. In turn this may facilitate targeted risk-reducing interventions, including endoscopic surveillance, preventative surgery and chemoprophylaxis, which provide opportunities for cancer prevention. This guideline is an update from the 2010 British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland (BSG/ACPGBI) guidelines for colorectal screening and surveillance in moderate and high-risk groups; however, this guideline is concerned specifically with people who have increased lifetime risk of CRC due to hereditary factors, including those with Lynch syndrome, polyposis or a family history of CRC. On this occasion we invited the UK Cancer Genetics Group (UKCGG), a subgroup within the British Society of Genetic Medicine (BSGM), as a partner to BSG and ACPGBI in the multidisciplinary guideline development process. We also invited external review through the Delphi process by members of the public as well as the steering committees of the European Hereditary Tumour Group (EHTG) and the European Society of Gastrointestinal Endoscopy (ESGE). A systematic review of 10 189 publications was undertaken to develop 67 evidence and expert opinion-based recommendations for the management of hereditary CRC risk. Ten research recommendations are also prioritised to inform clinical management of people at hereditary CRC risk.

British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines

These consensus guidelines were jointly commissioned by the British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE). They provide an evidence-based framework for the use of surveillance colonoscopy and non-colonoscopic colorectal imaging in people aged 18 years and over. They are the first guidelines that take into account the introduction of national bowel cancer screening. For the first time, they also incorporate surveillance of patients following resection of either adenomatous or serrated polyps and also post-colorectal cancer resection. They are primarily aimed at healthcare professionals, and aim to address:Which patients should commence surveillance post-polypectomy and post-cancer resection?What is the appropriate surveillance interval?When can surveillance be stopped? two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument provided a methodological framework for the guidelines. The BSG's guideline development process was used, which is National Institute for Health and Care Excellence (NICE) compliant.two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The key recommendations are that the high-risk criteria for future colorectal cancer (CRC) following polypectomy comprise either:two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps This cohort should undergo a one-off surveillance colonoscopy at 3 years. Post-CRC resection patients should undergo a 1 year clearance colonoscopy, then a surveillance colonoscopy after 3 more years.

Feasibility of using narrow band imaging international colorectal endoscopic classification for diagnosing colorectal neoplasia in China: A multicenter pilot observational study

OBJECTIVE

We aimed to investigate whether Chinese endoscopists without narrow-band imaging (NBI) experiences could achieve high accuracy in the real-time diagnosis of colorectal polyps using NBI International Colorectal Endoscopic (NICE) classification after web-based training.

METHODS

Altogether 15 endoscopists from five centers with no NBI experiences followed a short, web-based training program on the NICE classification and took web-based test. Their performances were compared with 15 matched experienced endoscopists with no NBI experience who received no NBI training. These 15 trained endoscopists then made real-time diagnoses of colorectal neoplasia. A logistic regression was used to assess potential predictors of diagnostic performance.

RESULTS

Compared with those who received no training, trained endoscopists achieved comparable overall accuracy (85.3% vs 83.1%, P = 0.408) and accuracy at a high-confidence level (87.0% vs 86.0%, P = 0.670), but had a higher confidence rate (86.1% vs 83.7%, P = 0.004) for the diagnosis of neoplasia. Real-time diagnostic accuracy, sensitivity and specificity were 94.3% (95% confidence interval [CI] 91.5%-96.2%), 96.2% (95% CI 93.4%-97.9%) and 85.3% (95% CI 74.8%-92.1%) at high-confidence level. The high-confidence level was the strongest predictor of real-time diagnostic accuracy (odds ratio 12.66, P < 0.001).

CONCLUSIONS

Web-based training can improve the confidence level of endoscopists in accurately diagnosing colorectal polyps using the NICE classification. Chinese endoscopists can achieve high accuracy in diagnosing colorectal neoplasia at a high confidence level (ClinicalTrials ID: NCT02033980).