Endoscopic and histological risk stratification for gastric cancer using gastric intestinal metaplasia.

BACKGROUND AND AIM: Intestinal metaplasia (IM) of the gastric mucosa is strongly associated with the risk of gastric cancer (GC). This study was performed to investigate the usefulness of endoscopic and histological risk stratification for GC using IM. METHODS: This was a post-hoc analysis of a multicenter prospective study involving 10 Japanese facilities (UMINCTR000027023). The ridge/tubulovillous pattern, light blue crest (LBC), white opaque substance (WOS), endoscopic grading of gastric IM (EGGIM) score using non-magnifying image-enhanced endoscopy, and operative link on gastric IM assessment (OLGIM) were evaluated for their associations with GC risk in all patients. RESULTS: In total, 380 patients (115 with GC and 265 without GC) were analyzed. The presence of an LBC (limited to antrum: odds ratio [OR] 2.4 [95% confidence interval 1.1-5.0], extended to corpus: OR 3.6 [2.1-6.3]), the presence of WOS (limited to antrum: OR 3.0 [1.7-5.3], extended to corpus: OR 4.2 [2.1-8.2]), and histological IM (limited to antrum: OR 3.2 [1.4-7.4], extended to corpus: OR 8.5 [4.5-16.0]) were significantly associated with GC risk. Additionally, the EGGIM score (5-8 points: OR 8.8 [4.4-16.0]) and OLGIM (stage III/IV: OR 12.5 [6.1-25.8]) were useful for stratification of GC risk. The area under the receiver operating characteristic curve value for GC risk was 0.740 for OLGIM and 0.706 for EGGIM. CONCLUSIONS: The LBC, WOS, EGGIM, and OLGIM were strongly associated with GC risk in Japanese patients. This finding can be useful for GC risk assessment in daily clinical practice.

Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort.

BACKGROUND & AIMS: We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study. METHODS: We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C). RESULTS: Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS. CONCLUSION: ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

Numerous lesions of gastric adenocarcinoma of fundic-gland and fundic gland-mucosa type in a patient.

A man in his 60 s underwent upper gastrointestinal endoscopy at our hospital, which revealed a 30-mm elevated lesion in the upper stomach (main lesion). There were several discolored, flat mucosal lesions and slightly elevated, reddish, subepithelial mass-like lesions (multiple secondary lesions) in the gastric fornix and body. Histopathological examination of several biopsied secondary lesions revealed gastric adenocarcinoma of fundic-gland type (GA-FG) or gastric adenocarcinoma of fundic gland-mucosa type (GA-FGM). The main lesion was suspected to be GA-FGM on magnifying endoscopy with narrow-band imaging. It was removed using endoscopic submucosal dissection for therapeutic and diagnostic purposes. The histopathological diagnosis of the resected lesion was GA-FGM, which was surrounded by two GA-FGM and > 30 GA-FG lesions. Total gastrectomy was considered; however, the patient declined further surgical treatment. Therefore, he was followed up with biannual endoscopy and computed tomography. At five years postoperatively, no tumor growth or metastasis has been observed.

Thiopurine naivety at tacrolimus induction is a predictor of long-term remission in patients with intractable ulcerative colitis who responded to tacrolimus.

BACKGROUND: The short-term efficacy of tacrolimus (Tac) for steroid-dependent and steroid-resistant refractory ulcerative colitis (UC) has been demonstrated; however, its long-term outcomes have not been well documented. Thus, this study aimed to clarify the long-term outcomes of patients who achieved Tac-induced remission and identify its predictors. METHODS: This study included patients with moderate-to-severe active UC who started receiving Tac at our hospital between July 2004 and December 2016. Short-term treatment response was assessed using the Lichtiger index 3 months after starting Tac, and responding patients were further followed up to assess long-term outcomes. The primary endpoint was the relapse-free survival after Tac-induced remission, and the secondary endpoint was the identification of factors associated with relapse after Tac-induced remission. RESULTS: The cumulative relapse-free survival rate at 10 years after Tac-induced remission was 33.2%. Multivariate analysis revealed that being thiopurine naïve at Tac induction was associated with the absence of relapse (hazard ratio: 0.45; 95% confidence interval: 0.22-0.92). CONCLUSIONS: Approximately one-third of patients who achieved Tac-induced remission maintained long-term remission. Being thiopurine naïve at Tac induction was a predictor of the absence of relapse.

Magnifying endoscopy with narrow-band imaging for diagnosis of subtype of gastric intestinal metaplasia.

BACKGROUND AND AIM: Patients with incomplete gastric intestinal metaplasia (GIM) have a higher risk of gastric cancer (GC) than those with complete GIM. We aimed to clarify whether micromucosal patterns of GIM in magnifying endoscopy with narrow-band imaging (M-NBI) were useful for diagnosis of incomplete GIM. METHODS: We enrolled patients with a history of endoscopic resection of GC or detailed inspection for suspicious or definite GC. The antrum greater curvature and corpus lesser curvature were regions of interest. Areas with endoscopic findings of light blue crest and/or white opaque substance (WOS) were defined as endoscopic GIM, and subsequent M-NBI was applied. Micromucosal patterns were classified into Foveola and Groove types, and targeted biopsies were performed on GIM with each pattern. GIM was classified into complete and incomplete types using mucin (MUC)2, MUC5AC, MUC6, and CD10 immunohistochemical staining. The primary endpoint was the association between micromucosal pattern and histological subtype. The secondary endpoint was endoscopic findings associated with incomplete GIM. RESULTS: We analyzed 98 patients with 156 GIMs. Univariate analysis (odds ratio [OR] 3.4, P = 0.004), but not multivariate analysis (OR 0.87, P = 0.822), demonstrated a significant association between micromucosal pattern and subtype. The antrum (OR 3.7, P = 0.006) and WOS (OR 43, P = 0.002) were independent predictors for incomplete GIM. The WOS had 69% sensitivity and 93% specificity. CONCLUSIONS: The M-NBI micromucosal pattern is not useful for diagnosis of GIM subtype. WOS is a promising endoscopic indicator for diagnosis of incomplete GIM. (UMIN-CTR000041119).

Advanced diagnostic endoscopy in the upper gastrointestinal tract: Review of the Japan Gastroenterological Endoscopy Society core sessions.

We held four upper gastrointestinal tract advanced diagnostic endoscopy sessions from the 89th to the 92nd Congress of the Japan Gastroenterological Endoscopy Society. The most common region addressed was the stomach in 25 presentations, followed by the esophagus in 23, duodenum in five, and other in one. Looking at techniques discussed, the most common image enhancement method discussed was narrowband imaging in 29 presentations, blue laser imaging, and linked color imaging (LCI) in 10 each, dual red imaging in three, and autofluorescence imaging in one. Furthermore, there were presentations of new techniques such as M-Chromo-LCI and acetic acid-indigo carmine mixture LCI. There were also six presentations regarding probe-based confocal laser endomicroscopy, and one of endocytoscopy techniques. We also saw presentations of images of gastric subepithelial tumors within the submucosa, 3D endoscopy, the development of computer-aided detection systems for early cancers, and fluorescent imaging.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study.

OBJECTIVES: Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT. METHODS: Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42. RESULTS: We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively. CONCLUSION: Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

A comparative study of demarcation line diagnostic performance between non-magnifying observation with white light and non-magnifying observation with narrow-band light for early gastric cancer.

BACKGROUND AND AIMS: With the improvement in endoscopic equipment functions, narrow-band imaging (NBI) for endoscopic observation of the stomach, which is an organ with a large lumen, is now feasible. Studies evaluating the NBI utility without magnifying endoscopy to diagnose the invasion extent for the demarcation line identification in early gastric cancer have not been reported. This study aimed to investigate the demarcation line diagnostic performance of NBI in early gastric cancer compared to that of white-light imaging (WLI) using prospectively collected consecutive specimens from early gastric cancer patients. METHODS: Thirty consecutive lesions were collected from patients who underwent endoscopic submucosal dissection for early gastric cancer. Next, 30 NBI and 30 WLI images, each with the same degree of gastric wall extension, angle, and layout for one lesion, were selected, and a total of 60 images were prepared for testing. The early gastric cancer invasion ranges in the endoscopic images was plotted using the web-developed software, and 264 independent endoscopists, unaware of the diagnosis, performed the web tests, with the concordance rates between the ranges of responses. After estimating the actual early gastric cancer invasion ranges, the NBI and WLI results were compared. RESULTS: The concordance rates for NBI and WLI images were 43.1% (95% confidence interval [CI] 42.5-43.7%) and 37.2% (95% CI 36.6-37.7%), respectively, showing that the concordance rate for NBI was significantly higher than that for WLI. CONCLUSION: This study suggested that NBI was more useful for identifying demarcation lines than WLI.

Visualization of Absorbed Lipid in the Normal Duodenal Epithelium Using Magnifying Endoscopy with Narrow-Band Imaging.

BACKGROUND: Subepithelial microvascular pattern cannot be visualized on the surface of adenoma and carcinoma by magnifying endoscopy due to a white opaque substance (WOS), which consists of minute lipid droplets accumulated in the neoplastic epithelium. AIMS: We aimed to investigate whether the WOS is visualized in the duodenum after exogenous fat loading (FL) administration in an open-label, randomized, controlled study. METHODS: The patients scheduled to undergo endoscopic therapy for gastric epithelial neoplasms were enrolled in the study. They were randomly assigned to the FL or non-FL group. An initial (before FL administration) and follow-up (after two to three weeks) endoscopic examinations were conducted to observe the duodenal mucosa using magnifying narrow-band imaging. Each patient in the FL group consumed 250 ml of Ensure H® four hours before the follow-up examination. Two experienced endoscopists determined the grade of the WOS. FL test results were judged positive for patients who showed a higher grade at the follow-up examination than at the initial examination. The rate of positive test results was compared between the two groups. RESULTS: Twenty patients (10 in the FL and 10 in the non-FL groups) were included. FL test results were positive for all 10 patients in the FL group, while they were negative for all 10 patients in the non-FL group (P < 0.001 by Fisher's exact test). CONCLUSIONS: Lipids loaded onto normal duodenal epithelium were absorbed, and the absorbed lipid droplets appeared as WOS on magnifying narrow-band imaging.

Long-term outcomes of endoscopic balloon dilation for intestinal strictures in patients with Crohn's disease during maintenance treatment with anti-tumor necrosis factor alpha antibodies.

BACKGROUND AND AIMS: Efficacy of endoscopic balloon dilation (EBD) for intestinal strictures in patients with Crohn's disease (CD) receiving anti-tumor necrosis factor alpha antibodies (anti-TNF) as maintenance therapy is unclear. We investigated the long-term efficacy and safety of EBD for intestinal strictures in patients with CD receiving anti-TNF. METHODS: We retrospectively analyzed data from patients with CD who received anti-TNF as maintenance therapy from 2008 to 2017, underwent EBD, and were followed up for ≥6 months. The primary endpoint was the cumulative surgery-free rate. The main secondary endpoints were technical success, repeat EBD rate, risk factors affecting surgical outcomes, and safety. RESULTS: Seventy-two patients with CD were assessed. The median observation period after EBD was 50 months. The technical success rate was 67%. The 3- and 5-year cumulative surgery-free rates were 81.1% and 73.5%, respectively. The repeat EBD rate was 74%. Multivariable analyses showed that risk factors affecting surgical outcomes were age at disease onset ≤16 years (hazard ratio 3.69; 95% confidence interval 1.36-10.01; P = 0.011). Serious complications requiring surgery developed in three patients. CONCLUSIONS: Endoscopic balloon dilation was an effective and safe short-term treatment and a useful long-term treatment for CD patients with intestinal strictures receiving anti-TNF as maintenance therapy.

Early gastric cancer detection in high-risk patients: a multicentre randomised controlled trial on the effect of second-generation narrow band imaging.

OBJECTIVE: Early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2G-NBI) can improve early detection, is unknown. DESIGN: This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (WLI) followed by secondary 2G-NBI (WLI group: n=2258) and primary 2G-NBI followed by secondary WLI (2G-NBI group: n=2265) performed by the same examiner. Suspected early gastric cancer (EGC) lesions in both groups were biopsied. Primary endpoint was the rate of EGC patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for EGC in suspicious lesions detected (primary examination). RESULTS: EGCs were found in 44 (1.9%) and 53 (2.3%; p=0.412) patients in the WLI and 2G-NBI groups, respectively, during primary EGD. In a post hoc analysis, the overall rate of lesions detected at the second examination was 25% (n=36/145), with no significant differences between groups. PPV for EGC in suspicious lesions was 13.5% and 20.9% in the WLI (50/371 target lesions) and 2G-NBI groups (59/282 target lesions), respectively (p=0.015). CONCLUSION: The overall sensitivity of primary endoscopy for the detection of EGC in high-risk patients was only 75% and should be improved. 2G-NBI did not increase EGC detection rate over conventional WLI. The impact of a slightly better PPV of 2G-NBI has to be evaluated further. TRIAL REGISTRATION NUMBER: UMIN000014503.

Characteristic endoscopic findings of gastric adenocarcinoma of fundic-gland mucosa type.

BACKGROUND AND STUDY AIMS: Gastric adenocarcinoma of fundic-gland type (GA-FG) was first proposed as a new entity of gastric adenocarcinoma in 2010. Subsequently, gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM) was reported as a subtype of gastric adenocarcinoma. This study aimed to investigate the endoscopic findings of GA-FGM and to evaluate the differences between GA-FGM and GA-FG. PATIENTS AND METHODS: This was a single-center retrospective study. Participants were selected from patients with gastric cancer treated at Fukuoka University Chikushi Hospital, between September 2007 and May 2020. Patients histologically diagnosed with GA-FGM or GA-FG were enrolled, and endoscopic findings were analyzed in detail. RESULTS: A total of 12 GA-FGM lesions (12 patients) and 14 GA-FG lesions (13 patients) were analyzed. The two lesion types showed similar features: most lesions were of elevated type, located in the upper stomach, and developed in the stomach without Helicobacter pylori infection. On conventional endoscopy using the dye-spraying method, well-demarcated fine granular areas were observed in 7 GA-FGM lesions (58%) but not in any GA-FG lesions, with a significant difference between the two groups (P = 0.001). Magnifying endoscopy with narrow-band imaging (NBI) showed that 11 GA-FGM lesions (92%) met the diagnostic criteria for cancer according to the vessel plus surface classification system, whereas none of the GA-FG lesions met the same criteria (0%, 0/14) (P = 0.001). CONCLUSION: Our results suggest that magnifying endoscopy with NBI is a potentially useful method for the diagnosis of GA-FGM.

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition).

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Usefulness of an artificial intelligence system for the detection of esophageal squamous cell carcinoma evaluated with videos simulating overlooking situation.

OBJECTIVES: Artificial intelligence (AI) systems have shown favorable performance in the detection of esophageal squamous cell carcinoma (ESCC). However, previous studies were limited by the quality of their validation methods. In this study, we evaluated the performance of an AI system with videos simulating situations in which ESCC has been overlooked. METHODS: We used 17,336 images from 1376 superficial ESCCs and 1461 images from 196 noncancerous and normal esophagi to construct the AI system. To record validation videos, the endoscope was passed through the esophagus at a constant speed without focusing on the lesion to simulate situations in which ESCC has been missed. Validation videos were evaluated by the AI system and 21 endoscopists. RESULTS: We prepared 100 video datasets, including 50 superficial ESCCs, 22 noncancerous lesions, and 28 normal esophagi. The AI system had sensitivity of 85.7% (54 of 63 ESCCs) and specificity of 40%. Initial evaluation by endoscopists conducted with plain video (without AI support) had average sensitivity of 75.0% (47.3 of 63 ESCC) and specificity of 91.4%. Subsequent evaluation by endoscopists was conducted with AI assistance, which improved their sensitivity to 77.7% (P = 0.00696) without changing their specificity (91.6%, P = 0.756). CONCLUSIONS: Our AI system had high sensitivity for the detection of ESCC. As a support tool, the system has the potential to enhance detection of ESCC without reducing specificity. (UMIN000039645).

Learning Effect of Diagnosing Depth of Invasion Using Non-Extension Sign in Early Gastric Cancer.

BACKGROUND: Determining the depth of invasion is important when considering therapeutic strategies for early gastric cancer (EGC). We determined the effects of learning the non-extension sign, that is, an index of T1b2 in EGC, on identifying its depth of invasion. METHODS: Endoscopic images of 40 EGC cases (20 showing positive non-extension sign on endoscopy as T1b2 and 20 showing negative non-extension sign on endoscopy as T1a-T1b1) were randomly displayed on PowerPoint. Participants read endoscopy findings (pretest) and attended a 60-min lecture on how to read the non-extension sign. Then, they read the same images using the non-extension sign as the marker (posttest). The primary endpoint was a change in accuracy rate for determining the depth of invasion before and after attending the lecture, for nonexperts (< 80%). RESULTS: Among 35 endoscopists, 12 were nonexperts; their test results were used for analyses. Accuracy rates for pretest and posttest among nonexperts were 75.2 and 82.5%, respectively, showing a significant increase in the accuracy rate after learning to read the non-extension sign (p = 0.003). CONCLUSION: Nonexperts' diagnostic ability to determine the depth of invasion of EGC improved by learning to read the non-extension sign. Thus, the non-extension sign is considered a simple and useful diagnostic marker.

Guidelines for endoscopic diagnosis of early gastric cancer.

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

An Asian consensus on standards of diagnostic upper endoscopy for neoplasia.

BACKGROUND: This is a consensus developed by a group of expert endoscopists aiming to standardise the preparation, process and endoscopic procedural steps for diagnosis of early upper gastrointestinal (GI) cancers. METHOD: The Delphi method was used to develop consensus statements through identification of clinical questions on diagnostic endoscopy. Three consensus meetings were conducted to consolidate the statements and voting. We conducted a systematic literature search on evidence for each statement. The statements were presented in the second consensus meeting and revised according to comments. The final voting was conducted at the third consensus meeting on the level of evidence and agreement. RESULTS: Risk stratification should be conducted before endoscopy and high risk endoscopic findings should raise an index of suspicion. The presence of premalignant mucosal changes should be documented and use of sedation is recommended to enhance detection of superficial upper GI neoplasms. The use of antispasmodics and mucolytics enhanced visualisation of the upper GI tract, and systematic endoscopic mapping should be conducted to improve detection. Sufficient examination time and structured training on diagnosis improves detection. Image enhanced endoscopy in addition to white light imaging improves detection of superficial upper GI cancer. Magnifying endoscopy with narrow-band imaging is recommended for characterisation of upper GI superficial neoplasms. Endoscopic characterisation can avoid unnecessary biopsy. CONCLUSION: This consensus provides guidance for the performance of endoscopic diagnosis and characterisation for early gastric and oesophageal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early upper GI cancers.

Analysis of factors related to poor outcome after e-learning training in endoscopic diagnosis of early gastric cancer using magnifying narrow-band imaging.

BACKGROUND AND AIMS: An e-learning system teaching endoscopic diagnostic process for early gastric cancer using magnifying endoscopy with narrow-band imaging (M-NBI) was established, and its efficacy in improving the diagnostic performance for early gastric cancer was proven in a multicenter randomized controlled trial. The aim of this study was to clarify the difference in learning effect in each lesion characteristic. METHODS: Three hundred sixty-five participants diagnosed 40 gastric lesions based on M-NBI findings using the vessel-plus-surface classification system. The diagnosis data collected from each participant were assessed in this study. The accuracy of NBI cancer diagnosis was assessed using area under the receiver operating characteristics curve (AUC/ROC) analysis. AUC/ROCs were separately calculated in each lesion characteristic (shape and size), and the data were compared between tests 1 and 3. RESULTS: Continuous net reclassification improvement (cNRI) analysis of all lesions revealed significant improvement in reclassification when participants underwent e-learning (cNRI, 1.17; P < .01). The integrated discrimination improvement analysis demonstrated that the e-learning system improved diagnostic ability (.19; P < .01). According to the analysis depending on the lesion's characteristics, high AUC/ROCs were demonstrated in depressed and small lesions (<10 mm; .90 and .93, respectively). The cNRI analysis showed remarkable e-learning improvement in both depressed (cNRI, 1.33; P < .01) and small lesions (cNRI, 1.46; P < .01). However, no significant e-learning improvement was observed in elevated or flat lesions. CONCLUSIONS: In M-NBI education for endoscopists, a good learning outcome was obtained in depressed and small lesions, but a poor learning outcome was demonstrated in elevated and flat lesions. (Clinical trial registration number: UMIN000008569.).

Endoscopic microanatomy of the normal gastrointestinal mucosa with narrow band technology and magnification.

The development of high-definition endoscopes with optical zoom, along with the use of the digital chromoendoscopy and staining, has given endoscopists the possibility to study the microanatomy of the gastrointestinal mucosa in vivo. The recognition of the changes in the microstructure of the surface and microvascular architecture such as those that occur in neoplastic lesions allow us to characterize these lesions in order to decide on the best course of clinical action. The current greater availability of endoscopes with optical zoom in western countries has allowed the use of this technology in routine clinical practice to spread. In this article we review the basic concepts of magnifying endoscopy and the normal endoscopic microanatomy of the oesophageal, gastric, duodenal, ileal and colonic mucosa.

Comparison of the diagnostic performance between magnifying chromoendoscopy and magnifying narrow-band imaging for superficial colorectal neoplasms: an online survey.

BACKGROUND AND AIMS: Magnifying narrow-band imaging (mag-NBI) and magnifying chromoendoscopy using crystal violet staining for pit pattern analysis (pit pattern) is highly accurate for diagnosing invasion depth of superficial colorectal neoplasms. However, NBI and pit pattern have not been compared. METHODS: We conducted an online survey of endoscopists interested in image-enhanced endoscopy. Still images using white light, mag-NBI, and pit pattern were collected from lesions diagnosed at the National Cancer Center Hospital (NCCH), Tokyo, Japan. Sixty endoscopists from outside NCCH who typically use magnifying endoscopy were recruited for this survey. We assessed the diagnostic accuracy using receiver operating characteristic (ROC) analysis based on a calculation of the area under the ROC curve. RESULTS: One hundred early colorectal neoplasms were selected for this survey. Histopathology revealed that, although 67 of the lesions had high-grade dysplasia or carcinoma with superficial submucosal (SM-s) invasion, the other 33 lesions had a carcinoma with deep submucosal invasion (SM-d). Comparing the area under the ROC curve from mag-NBI with that of pit pattern, the latter showed significantly higher diagnostic accuracy for depth invasion (0.83 [95% CI, 0.81-0.85] for mag-NBI, 0.88 [95% CI, 0.85-0.89] for pit pattern, P = .013). CONCLUSIONS: Pit pattern should be the first choice for diagnosing invasion depth as the most reliable modality rather than mag-NBI.