Linked color imaging identifies important risk factors associated with gastric cancer after successful eradication of Helicobacter pylori

Linked color imaging and upper gastrointestinal neoplasia

White light imaging (WLI) can sometimes miss early upper gastrointestinal (UGI) neoplasms, particularly minimal changes and flat lesions. Moreover, endoscopic diagnosis of UGI neoplasia is strongly influenced by the condition of the surrounding mucosa. Recently, image-enhanced endoscopy techniques have been developed and used in clinical practice; one of which is linked color imaging (LCI), which has an expanded color range for better recognition of slight differences in mucosal color and enables easy diagnosis and differentiation of noncancerous mucosa from carcinoma. LCI does not require magnified observation and can clearly visualize structures using an ultrathin scope; therefore, it is useful for screening and surveillance endoscopy. LCI is particularly useful for detecting gastric cancer after Helicobacter pylori eradication, which accounts for most gastric cancers currently discovered, and displays malignant areas in orange or orange-red surrounded by intestinal metaplasia in lavender. Data on the use of convolutional neural network and computer-aided diagnosis with LCI for UGI neoplasm detection are currently being collected. Further studies are needed to determine the clinical role of LCI and whether it can replace WLI.

Map-Like Redness Development After Eradication Therapy for Helicobacter pylori Infection: Prospective Multicenter Observational Study

BACKGROUND

Map-like redness, pathological intestinal metaplasia, is observed in one-fourth to one-third of patients 1 year after Helicobacter pylori eradication therapy, mainly in the corpus, and is a newly identified endoscopic risk factor for gastric cancer development after eradication. However, it is unclear whether intestinal metaplasia is present before eradication at the site where the map-like redness appears. We aimed to identify endoscopic findings that predict the occurrence of map-like redness before H. pylori eradication.

MATERIALS AND METHODS

As a prospective multicenter trial, the characteristics of patients in whom map-like redness developed after eradication, and the association between the endoscopic severity of gastritis and the development of map-like redness in patients who underwent endoscopy before and 1-year after eradication were investigated.

RESULTS

The rate of map-like redness in all 93 patients 1-year postsuccessful eradication was 30.1% (95% confidence interval [CI]: 21.0-40.5). All patients with map-like redness were endoscopically observed to have intestinal metaplasia before eradication, in the site that subsequently developed map-like redness. Patients who developed map-like redness were older, had more severe intestinal metaplasia and nodularity and a higher total score on the Kyoto Classification of Gastritis both before and after eradication than patients who did not. On multivariate analysis, map-like redness was found to be associated with posttreatment intestinal metaplasia (odds ratio: 8.144; 95% CI: 2.811-23.592).

CONCLUSIONS

In all patients who developed map-like redness after eradication, endoscopic intestinal metaplasia was observed at the site developed map-like redness before eradication therapy. Map-like redness was especially observed in patients with more severe intestinal metaplasia at 1-year after eradication. Such patients require increased attention at surveillance endoscopy, owing to generally having a higher risk of gastric cancer development.

TRIAL REGISTRATION

University Hospital Medical Information Network: UMIN000044707.

Characteristic endoscopic findings in Helicobacter pylori diagnosis in clinical practice

INTRODUCTION

Helicobacter pylori is a major risk factor for gastric cancer. In addition to eradication therapy, early-phase detection of gastric cancer through screening programs using high-vision endoscopy is also widely known to reduce mortality. Although European and US guidelines recommend evaluation of atrophy and intestinal metaplasia by high-vision endoscopy and pathological findings, the guideline used in Japan - the Kyoto classification of gastritis - is based on endoscopic evaluation, and recommends the grading of risk factors. This system requires classification into three endoscopic groups: H. pylori-negative, previous H. pylori infection (inactive gastritis), and current H. pylori infection (active gastritis). Major endoscopic findings in active gastritis are diffuse redness, enlarged folds, nodularity, mucosal swelling, and sticky mucus, while those in H pylori-related gastritis - irrespective of active or inactive status - are atrophy, intestinal metaplasia, and xanthoma.

AREAS COVERED

This review describes the endoscopic characteristics of current H. pylori infection, and how characteristic endoscopic findings should be evaluated.

EXPERT OPINION

Although the correct evaluation of endoscopic findings related to H. pylori remains necessary, if findings of possible infection are observed, it is important to diagnose infection by detection methods with high sensitivity and specificity, including the stool antigen test and urea breath test.

The value of LCI-based modified Kyoto classification risk scoring system in predicting the risk of early gastric cancer

OBJECTIVE

To study and compare the value of the Kyoto classification risk scoring system and the modified Kyoto classification risk scoring system based on linked color imaging (LCI) in predicting the risk of early gastric cancer.

METHODS

One hundred and fifty patients with pathologically confirmed non-cardia early gastric cancer by endoscopic LCI and 150 non-gastric cancer patients matched for age and gender were included. Basic patient data and whole gastric endoscopic images under LCI were collected, and the images were scored according to the LCI-based Kyoto classification risk scoring system and the LCI-based modified Kyoto classification risk scoring system.

RESULTS

Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based modified Kyoto classification risk scoring system had a higher AUC for predicting the risk of early gastric cancer (0.723 vs. 0.784, p = 0.023), with a score of ≥3 being the best cutoff value for predicting the risk of early gastric cancer (sensitivity 61.33%, specificity 86.00%), and scores of 3 to 5 were significantly associated with early gastric carcinogenesis significantly (OR = 9.032, 95% CI: 4.995-16.330, p < 0.001).

CONCLUSIONS

Compared with the LCI-based Kyoto classification risk scoring system, the LCI-based Kyoto modified classification risk scoring system has a better value for predicting the risk of early gastric cancer, and the score of 3 to 5 is a high-risk factor for the risk of early gastric cancer development, which is more strongly correlated with the risk of early gastric cancer.

Characteristics of Helicobacter pylori Eradication Therapy in Patients 80 Years or Older Living in a Metropolitan Area: A Multicenter Retrospective Study

BACKGROUND

The situation of Helicobacter pylori eradication therapy has been changing over time, owing to increases in antimicrobial-resistant strains, lifestyle improvements, and changes in indications for eradication. In Japan, eradication therapy is now available to all H. pylori-positive patients under the medical insurance system, and the potassium-competitive acid blocker vonoprazan has been used for eradication from 2015. Recently, with the aging of society, opportunities to provide eradication to elderly patients are increasing, but the current status and effectiveness of eradication in elderly patients remains unclear. Therefore, we aimed to investigate the trends of H. pylori eradication in a metropolitan area to determine the factors associated with successful H. pylori eradication in elderly patients older than 80 years.

METHODS

Trends in the eradication rates of patients who received first- or second-line eradication at 20 hospitals in the Tokyo metropolitan area from 2013 to 2023 were investigated.

RESULTS

The eradication rates in the per-protocol analysis were 82.3% (95% confidence interval [CI]: 81.2%-83.2%) for the first-line treatment (n = 6481), and 87.9% (86.9%-88.9%) for the second-line treatment (n = 4899). Multivariate analysis showed that independent factors for successful eradication in the first-line treatment were an age of older than 80 years (OR: 0.606; 95% CI: 0.448-0.822), peptic ulcers (vs. atrophic gastritis: 3.817; 3.286-4.433), and vonoprazan (vs. proton pump inhibiters (PPIs), 3.817; 3.286-4.433), and an age of older than 80 years (0.503; 0.362-0.699) and vonoprazan (1.386; 1.153-1.667) in the second-line treatment.

CONCLUSION

After 2015, the eradication rate of both first- and second-line therapies were maintained at a higher level than before 2015, owing to the use of vonoprazan. As the H. pylori eradication rate in patients older than 80 years was low, an effective strategy for these patients needs to be developed in the future.

Long-term endoscopic gastric mucosal changes up to 20 years after Helicobacter pylori eradication therapy

Helicobacter pylori eradication therapy reduces the risk of gastric cancer. However, it is unclear whether the severity of risk factors for gastric cancer such as atrophy and intestinal metaplasia are reduced after eradication in the long term. We aimed to study long-term changes in endoscopic risk factors for gastric cancer up to 20 years post-eradication. The endoscopic severity of gastritis according to the Kyoto Classification of Gastritis in 167 patients was retrospectively evaluated over an average follow-up 15.7 years. A significant improvement in mean total gastric cancer risk score (4.36 ± 1.66 to 2.69 ± 1.07, p < 0.001), atrophy (1.73 ± 0.44 to 1.61 ± 0.49, p = 0.004), and diffuse redness (1.22 ± 0.79 to 0.02 ± 0.13, p < 0.001) was observed compared to baseline in the Eradication group. However, there was no change in the never infection and current infection groups. The frequency of map-like redness increased over time until 15 years (3.6% to 18.7%, p = 0.03). The Cancer group had significantly higher risk scores at all time points. Endoscopic atrophy significantly improved in eradicated patients over long-term, suggested that eradication is one of the key elements in gastric cancer prevention. Individualized surveillance strategies based on endoscopic gastritis severity before eradication may be important for those at risk of gastric cancer.

Risk of map-like redness development after eradication therapy for Helicobacter pylori infection

BACKGROUND

Map-like redness is a newly identified endoscopic risk factor for gastric cancer in patients who received Helicobacter pylori eradication therapy. However, the incidence rate of map-like redness in patients who received eradication, and the risk factors for the development of map-like redness remain unclear. We hence aimed to investigate the incidence rate of map-like redness at 1-year post H. pylori eradication, and evaluated its associations with map-like redness and gastric cancer in relation with gastric condition.

MATERIALS AND METHODS

Endoscopic severity of gastritis and map-like redness were retrospectively evaluated according to the Kyoto Classification of Gastritis in patients who had undergone endoscopy before and after H. pylori eradication therapy.

RESULTS

The incidence rate of map-like redness for all 328 patients at a mean of 1.2 ± 0.6 years after eradication was 25.3% (95% confidence interval [CI]: 20.7%-30.4%). Patients who developed map-like redness were older, had more severe atrophy and intestinal metaplasia, a higher total score of the Kyoto Classification of Gastritis both before and after eradication, and a higher rate of gastric cancer history than patients who did not have map-like redness. On multivariate analysis, risk of map-like redness was increased in patients with intestinal metaplasia (odds ratio [OR]: 2.794, 95% CI: 1.155-6.757) and taking acid inhibitors (OR: 1.948, 95% CI: 1.070-3.547). Characteristics of H. pylori-positive patients with gastric cancer history were patients who were older (OR: 1.033, 95% CI: 1.001-1.066), taking acid inhibitors (OR: 4.456, 95% CI: 2.340-8.484), and with occurrence of map-like redness after eradication therapy (OR: 2.432, 95% CI: 1.264-4.679).

CONCLUSIONS

Map-like redness is observed in one fourth of patients at 1-year post eradication. Patients who developed map-like redness were found to have severe intestinal metaplasia and taking acid inhibitors, and hence such patients require increased attention at surveillance endoscopy.

Clinical usefulness of linked color imaging in identifying Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

Accurate diagnosis of Helicobacter pylori (H. pylori) infection status is a crucial premise for eradication therapy, as well as evaluation of risk for gastric cancer. Recent progress on imaging enhancement endoscopy (IEE) made it possible to not only detect precancerous lesions and early gastrointestinal cancers but also to predict H. pylori infection in real time. As a novel IEE modality, linked color imaging (LCI) has exhibited its value on diagnosis of lesions of gastric mucosa through emphasizing minor differences of color tone.

AIM

To compare the efficacy of LCI for H. pylori active infection vs conventional white light imaging (WLI).

METHODS

PubMed, Embase, Embase and Cochrane Library were searched up to the end of April 11, 2022. The random-effects model was adopted to calculate the diagnostic efficacy of LCI and WLI. The calculation of sensitivity, specificity, and likelihood ratios were performed; symmetric receiver operator characteristic (SROC) curves and the areas under the SROC curves were computed. Quality of the included studies was chosen to assess using the quality assessment of diagnostic accuracy studies-2 tool.

RESULTS

Seven original studies were included in this study. The pooled sensitivity, specificity, positive likelihood rate, and negative likelihood rate of LCI for the diagnosis of H. pylori infection of gastric mucosa were 0.85 [95% confidence interval (CI): 0.76-0.92], 0.82 (95%CI: 0.78-0.85), 4.71 (95%CI: 3.7-5.9), and 0.18 (95%CI: 0.10-0.31) respectively, with diagnostic odds ratio = 26 (95%CI: 13-52), SROC = 0.87 (95%CI: 0.84-0.90), which showed superiority of diagnostic efficacy compared to WLI.

CONCLUSION

Our results showed LCI can improve efficacy of diagnosis on H. pylori infection, which represents a useful endoscopic evaluation modality for clinical practice.

Characteristics of Gastric Mucosa-Associated Microbiota in Patients with Early Gastric Cancer After Successful Helicobacter pylori Eradication

BACKGROUND

Helicobacter pylori (H. pylori) is widely recognized as a definite carcinogen in gastric cancer (GC). Although H. pylori eradication reduces the risk of GC, GC recurrence has been detected even after successful H. pylori eradication. Recently, the analysis of gut microbiota was reported.

AIMS

This study aimed to evaluate the correlation between gastric mucosa-associated microbiota (G-MAM) and early gastric cancer (EGC) after successful H. pylori eradication.

METHODS

In this pilot study, G-MAM were collected during the esophagogastroduodenoscopy of 17 patients, receiving H. pylori eradication therapy at least 5 years ago. The patients were divided into those with EGC (the EGC group, 8 patients) and those without EGC (the NGC group, 9 patients). Microbial samples in the greater curvature of the pyloric site were obtained using an endoscopic cytology brush, and the G-MAM profiles of each sample were analyzed using 16S rRNA V3-V4 gene sequencing.

RESULTS

Between the two groups, there was no significant difference in the median age, sex, median period after successful eradication of H. pylori, the α diversity, and the average abundance at the phylum level. At the genus level, the average abundance of Unclassified Oxalobacteraceae, Capnocytophaga, and Haemophilus was significantly lower in the EGC group than in the NGC group (0.89 vs. 0.14%, P < 0.01, 0.28 vs. 0.00%, P < 0.01 and 5.84 vs. 2.16%, P = 0.034, respectively).

CONCLUSIONS

We demonstrated alternations in the profiles of G-MAM between the two groups. Our results suggest that G-MAM may influence carcinogenesis after successful H. pylori eradication.

Comparison of different risk stratifications for gastric cancer and establishing a simplified risk-scoring model based on the Kyoto classification

BACKGROUND AND AIM

The study aims to assess the value of different risk stratifications in diagnosing early gastric cancer (GC) and explore risk factors based on Kyoto gastritis classification.

METHODS

This study was a single-centered cross-sectional study; all epidemiological data and endoscopic findings were obtained prospectively. To evaluate the proportion of GC in each risk stratification and to compare the diagnostic performance of different methods using the receiver operating characteristic curve, univariable and multivariable analyses were used to explore the correlation between endoscopic findings and GC.

RESULTS

A total of 240 subjects were enrolled, and the diagnostic efficacy of the Kyoto Classification Score was similar to Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) stage, and the accuracy was higher than that of the Japanese scoring system and OLGA stage. Moderate atrophy (odds ratio [OR] = 3.52, 95% confidence interval [CI]: 1.52-8.16), severe atrophy (OR = 4.96, 95% CI: 1.75-14.04), map-like redness (OR = 9.89, 95% CI: 1.16-84.15), and xanthelasma (OR = 3.57, 95% CI: 1.15-11.15) were independent risk factors for GC. The simplified Kyoto classification (area under the receiver operating characteristic [AUROC] = 0.76, P = 0.58) based on multivariable analysis demonstrated favorable diagnostic value compared with traditional Kyoto classification score (AUROC = 0.74).

CONCLUSIONS

This study confirms the value of the Kyoto classification score and the OLGIM stage in the risk stratification of GC. Simplified Kyoto classification is also promising in risk assessment of GC but still requires validation in the population.

Endoscopic characteristics and high-risk background mucosa factors of early gastric cancer after helicobacter pylori eradication: a single-center retrospective study

Purpose

Gastric cancer still develops after successful Helicobacter pylori(Hp)eradication. In this study, we aimed to explore the characteristics and risks of mucosal factors.

Methods

A total of 139 early gastric cancers (EGC) diagnosed in 133 patients after successful eradication from January 2016 to December 2021 were retrospectively included in the Hp-eradication EGC group and 170 EGCs diagnosed in 158 patients were included in the Hp-positive EGC group. We analyzed the clinical, pathological, and endoscopic characteristics between the two groups to identify the features of EGC after Hp eradication. Another 107 patients with no EGC after Hp eradication were enrolled in a Hp-eradication non-EGC group. The background mucosal factors between the Hp-eradication EGC group and the Hp-eradication non-EGC group were compared to analyze the high-risk background mucosal factors of EGC after eradication. In addition, we divided the EGC group after Hp eradication into IIc type and non-IIc type according to endoscopic gross classification to assess the high-risk background factors of IIc-type EGC after Hp eradication.

Results

The endoscopic features of EGC after Hp eradication included location in the lower part of the stomach (p=0.001), yellowish color (p= 0.031), and smaller size (p=0.001). The moderate/severe gastric atrophy (GA), intestinal metaplasia (IM) in the corpus, severe diffuse redness, and map-like redness were risk factors for EGC after eradication (p=0.001, p=0.001, p=0.001, and p= 0.005, respectively). The Kyoto classification total score in the EGC group was higher than the non-EGC group (4 vs.3 p<0.001). A multivariate analysis revealed that depressed erosion (OR=3.42, 95% CI 1.35-8.65, p= 0.009) was an independent risk factor for IIc-type EGC after Hp eradication.

Conclusion

EGC after eradication are smaller and yellowish lesions located in the lower part of the stomach. The risk background mucosal factors include moderate/severe GA, IM in the corpus, severe diffuse redness, and map-like redness. The Kyoto classification total score of 4 or more after successful eradication treatment might indicate EGC risk. In addition, the IIc-type EGC should be cautioned in the presence of depressed erosion after Hp eradication.

Endoscopic diagnosis of Helicobacter pylori gastritis using white light imaging and texture and color enhancement imaging

Background and study aims  Texture and color enhancement imaging (TXI) is a new image-enhanced endoscopy that augments subtle tissue differences and color changes in gastric mucosa. This study aimed to compare the usefulness of TXI and white light imaging (WLI) for diagnosing Helicobacter pylori gastritis. Patients and methods  We retrospectively prepared one image set with 22 endoscopic images acquired by WLI and TXI from 60 consecutive patients individually. Five endoscopists independently reviewed the randomly displayed image sets and assessed the H. pylori infection status on endoscopy according to the Kyoto Classification of Gastritis. The primary endpoints were the accuracies of WLI and TXI in diagnosing H. pylori -active gastritis. The correlation of the endoscopic features with the three H. pylori infection statuses (current infection, past infection, and noninfection) was also evaluated. Results  Diagnostic accuracy for active gastritis was significantly higher in TXI than in WLI (85.3 % vs. 78.7 %; P  = 0.034). All the specific endoscopic features associated with H. pylori infection statuses had a higher odds ratio with TXI than with WLI. Additionally, interobserver agreement among the five reviewers was higher in TXI than in WLI, except for one pair. Conclusions  TXI may improve the endoscopic diagnosis accuracy for H. pylori infection.

Linked Color Imaging for Stomach

Image-enhanced endoscopy (IEE) plays an important role in the detection and further examination of gastritis and early gastric cancer (EGC). Linked color imaging (LCI) is also useful for detecting and evaluating gastritis, gastric intestinal metaplasia as a pre-cancerous lesion, and EGC. LCI provides a clear excellent endoscopic view of the atrophic border and the demarcation line under various conditions of gastritis. We could recognize gastritis as the lesions of the diffuse redness to purple color area with LCI. On the other hand, EGCs are recognized as the lesions of the orange-red, orange, or orange-white color area in the lesion of the purple color area, which is the surround atrophic mucosa with LCI. With further prospective randomized studies, we will be able to evaluate the diagnosis ability for EGC by IEE, and it will be necessary to evaluate the role of WLI/IEE and the additional effects of the diagnostic ability by adding IEE to WLI in future.

Kyoto classification of gastritis, virtual chromoendoscopy and artificial intelligence: Where are we going? What do we need?

Chronic gastritis (CG) is a widespread and frequent disease, mainly caused by Helicobacter pylori infection, which is associated with an increased risk of gastric cancer. Virtual chromoendoscopy improves the endoscopic diagnostic efficacy, which is essential to establish the most appropriate therapy and to enable cancer prevention. Artificial intelligence provides algorithms for the diagnosis of gastritis and, in particular, early gastric cancer, but it is not yet used in practice. Thus, technological innovation, through image resolution and processing, optimizes the diagnosis and management of CG and gastric cancer. The endoscopic Kyoto classification of gastritis improves the diagnosis and management of this disease, but through the analysis of the most recent literature, new algorithms can be proposed.

Current status and future perspective of linked color imaging for gastric cancer screening: a literature review

Screening endoscopy has advanced to facilitate improvements in the detection and prognosis of gastric cancer. However, most early gastric cancers (EGCs) have subtle morphological or color features that are difficult to detect by white-light imaging (WLI); thus, even well-trained endoscopists can miss EGC when using this conventional endoscopic approach. This review summarizes the current and future status of linked color imaging (LCI), a new image-enhancing endoscopy (IEE) method, for gastric screening. LCI has been shown to produce bright images even at a distant view and provide excellent visibility of gastric cancer due to high color contrast relative to the surrounding tissue. LCI delineates EGC as orange-red and intestinal metaplasia as purple, regardless of a history of Helicobacter pylori (Hp) eradication, and contributes to the detection of superficial EGC. Moreover, LCI assists in the determination of Hp infection status, which is closely related to the risk of developing gastric cancer. Transnasal endoscopy (ultra-thin) using LCI is also useful for identifying gastric neoplastic lesions. Recently, several prospective studies have demonstrated that LCI has a higher detection ratio for gastric cancer than WLI. We believe that LCI should be used in routine upper gastrointestinal endoscopies.

Third-Generation High-Vision Ultrathin Endoscopy Using Texture and Color Enhancement Imaging and Narrow-Band Imaging to Evaluate Barrett's Esophagus

It remains unclear whether texture- and color-enhancement imaging (TXI) and narrow-band imaging (NBI) provide an advantage over white-light imaging (WLI) in Barrett’s esophagus. We compared endoscopic findings and color differences between WLI and image-enhanced endoscopy (IEE) using a third-generation ultrathin endoscope. We retrospectively enrolled 40 patients who evaluated Barrett’s esophagus using WLI, TXI, and NBI. Color differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) color space among Barrett’s epithelium, esophageal, and gastric mucosa were compared among the endoscopic findings. As the secondary outcome, we assessed the subjective visibility score among three kinds of endoscopic findings. The prevalence of Barrett’s esophagus and gastroesophageal reflux disease (GERD) in WLI was 82.5% and 47.5%, respectively, and similar among WLI, TXI, and NBI. Color differences between Barrett’s epithelium and esophageal or gastric mucosa on NBI were significantly greater than on WLI (all p < 0.05). However, the color difference between Barrett’s epithelium and esophageal mucosa was significantly greater on NBI than TXI (p < 0.001), and the visibility score of Barrett’s epithelium detection was significantly greater on TXI than NBI (p = 0.022), and WLI (p = 0.016). High-vision, third-generation ultrathin endoscopy using NBI and TXI is useful for evaluating Barrett’s epithelium and GERD compared with WLI alone.

Characteristics and background mucosa status of early gastric cancer after Helicobacter pylori eradication: A narrative review

Helicobacter pylori (H pylori) eradication treatment can reduce the risk of gastric cancer. However, early gastric cancer (EGC) can still be detected after eradication. Meanwhile, EGC after eradication is challenging to diagnose by an endoscopist in some cases due to the lack of apparent characteristics and the complex mucosal status. This review aims to summarize the endoscopic and histological characteristics and the mucosal risk factors for gastric cancer after H pylori eradication. The literature was searched for possible reported gastric cancer after eradication in "PubMed." These included related clinical studies and reviews, and unrelated or non-English articles were excluded. Endoscopically, EGC displays a small, reddish and depressed lesion, indistinct border, "gastritis-like" appearance and submucosal invasion. Histologically, it is divided into surface differentiation, nontumorous epithelium, and intestinal type. The risk factors include severe gastric atrophy, intestinal metaplasia in the corpus, and map-like redness. In conclusion, these studies on the characteristics and risk mucosal factors of patients with gastric cancer after H pylori eradication will drive the establishment of a novel endoscopic surveillance and diagnosis system for H pylori-eradicated patients.

Diagnostic accuracy of linked colour imaging versus white light imaging for early gastric cancers: a prospective, multicentre, randomized controlled trial study

BACKGROUND

Linked colour imaging (LCI) is a novel new image-enhanced endoscopy (IEE) technology that produces bright and vivid images. The aim of this study was to assess the ability of LCI to improve the diagnostic accuracy of early gastric cancer (EGC) relative to white light imaging (WLI).

MATERIALS AND METHODS

We performed this study on patients undergoing screening endoscopy from 12 medical institutions in China. Patients were randomly assigned to receive WLI followed by LCI or LCI followed by WLI. The primary outcome was to compared the diagnostic accuracy between LCI and WLI for EGC/high-grade intraepithelial neoplasms. Secondary outcomes included the numbers of suspicious lesions, neoplastic lesions and examination time by using LCI detected versus using WLI.

RESULTS

A total of 1924 patients were randomly selected, and 1828 were included in the analysis. The diagnostic accuracy for EGC, which was 78.8% by using LCI and 68.4% by using WLI (p < .0001). More suspicious lesions were detected by LCI than by WLI (n = 1235 vs. 1036, p = .031), especially among differentiated EGC (p = .013). LCI greatly shortened the examination time compared with WLI (p = .019).

CONCLUSIONS

LCI has better accuracy and shorter examination time in diagnosing EGC than WLI (Clinical trial registration: NCT03092414).Key messagesCompared with white light imaging (WLI), the diagnostic accuracy, sensitivity and specificity increased by using LCI.More lesions were detected by LCI alone than by WLI alone, especially among differentiated EGC.LCI may be used as a screening tool for routine clinical observation.

Using texture and colour enhancement imaging to evaluate gastrointestinal diseases in clinical practice: a review

White light imaging (WLI) is the most common endoscopic technique used for screening of gastrointestinal diseases. However, despite the advent of a new processor that offers sufficient clear illumination and other advanced developments in endoscopic instrumentation, WLI alone is inadequate for detecting all gastrointestinal diseases with abnormalities in mucosal discoloration and morphological changes to the mucosal surface. The recent development of image-enhanced endoscopy (IEE) has dramatically improved the detection of gastrointestinal diseases. Texture and colour enhancement imaging (TXI) is a new type of IEE that enhances brightness, surface irregularities, such as elevations or depressions, and subtle colour changes. TXI with two modes, namely modes 1 and 2, can selectively enhance brightness in dark areas of an endoscopic image and subtle tissue differences such as slight morphological or colour changes while simultaneously preventing over-enhancement. Several clinical studies have investigated the efficacy of TXI for detecting and visualizing gastrointestinal diseases, including oesophageal squamous cell carcinoma (ESCC), Barret's epithelium, gastric cancer, gastric mucosal atrophy and intestinal metaplasia. Although TXI is often more useful for detecting and visualizing gastrointestinal diseases than WLI, it remains unclear whether TXI outperforms other IEEs, such as narrow-band imaging (NBI), in similar functions, and whether the performance of TXI modes 1 and 2 are comparable. Therefore, large-scale prospective studies are needed to compare the efficacy of TXI to WLI and other IEEs for endoscopic evaluation of patients undergoing screening endoscopy. Here, we review the characteristics and efficacy of TXI for the detection and visualization of gastrointestinal diseases.Key MessagesTXI mode 1 can improve the visibility of gastrointestinal diseases and qualitative diagnosis, especially for diseases associated with colour changes.The enhancement of texture and brightness with TXI mode 2 enables the detection of diseases, and is ideal for use in the first screening of gastrointestinal tract.

Efficacy of high-vision transnasal endoscopy using texture and colour enhancement imaging and narrow-band imaging to evaluate gastritis: a randomized controlled trial

BACKGROUND

A new image-enhanced endoscopy method called texture and colour enhancement imaging (TXI) enhances brightness, surface irregularities, and subtle colour changes in endoscopic images. However, it is unclear whether TXI and narrow-band imaging (NBI) with third-generation high-vision transnasal ultrathin endoscopy are advantageous over white-light imaging (WLI) for detecting atrophy, intestinal metaplasia, map-like redness and gastric cancer. We investigated to compare the endoscopic efficacy for evaluation of gastritis between TXI and NBI with high-vision transnasal endoscopy and clarified the endoscopic efficacy of TXI and NBI compared to WLI.

METHODS

We enrolled 60 patients who underwent high-vision transnasal endoscopy as part of a health check-up from March to November 2021 and randomized patients into two groups (the WLI-NBI group and the WLI-TXI group) using the minimization method based on Helicobacter pylori infection status, age and sex. Colour differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) colour space was compared between WLI and TXI or NBI.

RESULTS

No significant differences were observed in colour differences surrounding atrophy, intestinal metaplasia and map-like redness between NBI and TXI (p = .553, .057 and .703, respectively). Endoscopic scores based on the Kyoto classification of gastritis for atrophy, intestinal metaplasia, and map-like redness were similar between WLI and TXI. In contrast, NBI identified intestinal metaplasia at a significantly greater rate than WLI (p = .018). Further, colour differences surrounding atrophy and intestinal metaplasia on TXI and NBI were significantly greater than those on WLI (atrophy: TXI vs WLI p = .003, NBI vs WLI p < .001; intestinal metaplasia: TXI vs WLI p = .016, NBI vs WLI p < .001). However, TXI and NBI were not advantageous over WLI for detecting map-like redness.

CONCLUSION

Third-generation high-vision transnasal ultrathin endoscopy using TXI and/or NBI is useful for detecting atrophic borders and intestinal metaplasia.Key MessagesHigh-vision transnasal endoscopy using TXI or NBI is useful for diagnosing and detecting atrophy and intestinal metaplasia.TXI and NBI increase colour differences surrounding atrophy and intestinal metaplasia, thereby increasing diagnostic efficiency to improve risk stratification for gastric cancer.The image quality and detection rate have improved markedly with the latest ultrathin high-vision transnasal endoscopes.

Kyoto classification of gastritis: Advances and future perspectives in endoscopic diagnosis of gastritis

This editorial provides an update of the recent evidence on the endoscopy-based Kyoto classification of gastritis, clarifying the shortcomings of the Kyoto classification, and providing prospects for future research, with particular focus on the histological subtypes of gastric cancer (GC) and Helicobacter pylori (H. pylori) infection status. The total Kyoto score is designed to express GC risk on a score ranging from 0 to 8, based on the following five endoscopic findings: Atrophy, intestinal metaplasia (IM), enlarged folds (EF), nodularity, and diffuse redness (DR). The total Kyoto score reflects H. pylori status as follows: 0, ≥ 2, and ≥ 4 indicate a normal stomach, H. pylori-infected gastritis, and gastritis at risk for GC, respectively. Regular arrangement of collecting venules (RAC) predicts non-infection; EF, nodularity, and DR predict current infection; map-like redness (MLR) predicts past infection; and atrophy and IM predict current or past infection. Atrophy, IM, and EF all increase the incidence of H. pylori-infected GC. MLR is a specific risk factor for H. pylori-eradicated GC, while RAC results in less GC. Diffuse-type GC can be induced by active inflammation, which presents as EF, nodularity, and atrophy on endoscopy, as well as neutrophil and mononuclear cell infiltration on histology. In contrast, intestinal-type GC develops via atrophy and IM, and is consistent between endoscopy and histology. However, this GC risk-scoring design needs to be improved.

Images of laser and light-emitting diode colonoscopy for comparing large colorectal lesion visibility with linked color imaging and white-light imaging

OBJECTIVES

In light-emitting diode (LED) and laser colonoscopy, linked color imaging (LCI) superiority to white-light imaging (WLI) for polyp detection is shown separately. We analyzed the noninferiority of LCI between LED and laser colonoscopy and that of WLI (LECOL study).

METHODS

We prospectively collected nonpolypoid lesions with WLI and LCI using LED and laser colonoscopy from January 2021 to August 2021. All images were evaluated randomly by 12 endoscopists (six nonexperts and six experts in three institutions) using the polyp visibility score: 4, excellent; 3, good; 2, fair; and 1, poor. The comparison score (LED better/similar/laser better) for redness and brightness was evaluated for WLI and LCI pictures of each lesion.

RESULTS

Finally, 63 nonpolypoid lesions were evaluated, and the mean polyp size was 24.5 ± 13.4 mm. Histopathology revealed 13 serrated lesions and 50 adenomatous/cancerous lesions. The mean polyp visibility scores of LCI pictures were significantly higher than those of WLI in the LED (3.35 ± 0.85 vs. 3.08 ± 0.91, P < 0.001) and the laser (3.40 ± 1.71 vs. 3.05 ± 0.97, P < 0.001) group, and the noninferiority of LCI pictures between LED and laser was significant (P < 0.001). The comparison scores revealed that the evaluation of redness and brightness (LED better/similar/laser better) were 26.8%/40.1%/33.1% and 43.5%/43.5%/13.0% for LCI pictures (P < 0.001) and 20.6%/44.3%/35.1% and 60.3%/31.7%/8.0% for WLI pictures (P < 0.001), respectively.

CONCLUSION

The noninferiority of polyp visibility with WLI and LCI in LED and laser colonoscopy was shown. WLI and LCI of LED tended to be brighter and less reddish than those of laser.

Comparative Study of Helicobacter pylori-Infected Gastritis in Okinawa and Tokyo Based on the Kyoto Classification of Gastritis

The incidence of gastric cancer in Okinawa Prefecture is the lowest in Japan, which is attributed to differences in strains of Helicobacter pylori in Okinawa and other prefectures in Japan. Our aim was to compare the endoscopic findings of H. pylori-infected gastric mucosa in Okinawa and Tokyo. Patients who underwent upper gastrointestinal endoscopy (UGI) at Northern Okinawa Medical Center (Okinawa group) and Juntendo University Hospital (Tokyo group) from April 2019 to March 2020 were included. Patients diagnosed with H. pylori-infected gastric mucosa were retrospectively compared between the Okinawa and Tokyo groups according to the Kyoto Classification of Gastritis. The numbers of subjects (Okinawa/Tokyo) were 435/352, male/female ratio was 247:188/181:171, and age was 53.3 ± 14.7/64.6 ± 14.3 (mean ± standard deviation) years. Regarding the Kyoto Classification of Gastritis, the prevalence (Okinawa/Tokyo) of the closed type of atrophic gastritis was 73%/37% (p < 0.001), diffuse redness 80%/84% (p = 0.145), mucosal swelling 46%/46% (p = 0.991), enlarged fold 26%/32% (p = 0.048), spotty redness 77%/68% (p = 0.002), sticky mucus 17%/36% (p < 0.001), and intestinal metaplasia 32%/42% (p < 0.001). Age analysis also revealed that closed-type atrophy and spotty redness were more frequent in the Okinawa group than in the Tokyo group. There may be regional differences in endoscopic findings of H. pylori-infected gastric mucosa between Okinawa and Tokyo.

Enhanced Visibility in Evaluating Gastric Cancer and Helicobacter pylori-Associated Gastritis Using Linked Color Imaging with a Light-Emitting Diode Light Source

BACKGROUND

In Japan, laser light source (Laser) endoscopy is widely available, and the characteristics of light-emitting diode light source (LED) endoscopy have not been clarified.

AIMS

We assessed the visibility of early gastric cancers (EGCs) and Helicobacter pylori (H. pylori)-associated gastritis for LED endoscopy compared with laser endoscopy using white-light imaging (WLI) and linked color imaging (LCI).

METHODS

We assessed 99 lesions between February 2019 and March 2020. The visibility was scored from four (excellent visibility) to one (poor visibility) by evaluating videos including EGCs and gastric mucosa captured using WLI and LCI with LED endoscopy (LED-WLI and LED-LCI, respectively) and laser endoscopy (Laser-WLI and Laser-LCI, respectively). The primary end point was the non-inferiority of the visibility of EGCs and H. pylori-associated gastritis between LED-/Laser-WLI and LED-/Laser-LCI.

RESULTS

The visibility scores of EGCs for LED-/Laser-WLI and LED-/Laser-LCI were 3.14/2.97 and 3.39/3.35, respectively. The visibility scores of H. pylori-associated gastritis [intestinal metaplasia (IM), diffuse redness (DR), regular arrangement of collecting venules (RAC) and map-like redness (MR)] for LED-/Laser-WLI and LED-/Laser-LCI were 3.05/2.85 and 3.60/3.50 (IM), 2.76/2.50 and 2.96/2.86 (DR), 2.69/2.44 and 2.77/2.62 (RAC) and 2.97/2.75 and 3.39/3.27 (MR). Non-inferiority was demonstrated for visualizing EGCs and H. pylori-associated gastritis.

CONCLUSIONS

LED-WLI and LED-LCI can be used to visualize EGCs and H. pylori-associated gastritis with non-inferiority to Laser-WLI and Laser-LCI. Furthermore, even with LED, LCI was more effective than WLI for evaluating EGCs and H. pylori-associated gastritis. Therefore, LED endoscopy can be used to detect EGCs and evaluate H. pylori-associated gastritis accurately.

Linked color imaging effectively detects the endoscopic atrophic border in transnasal endoscopy

In oral endoscopy, linked color imaging (LCI) detects atrophic border and gastric mucosal diseases better than white light imaging (WLI), but its usefulness in transnasal endoscopy has not been fully investigated. Here, we retrospectively compared WLI and LCI using the L*a*b* color space in images from 57 patients aged ≥20 years who had undergone transnasal endoscopy as part of a health check-up from May 2016 to January 2017. We measured color differences at the atrophic/non-atrophic and fundic/pyloric mucosal borders. Gastritis severity scored using the Kyoto classification of gastritis was similar between the two techniques. However, in patients with current and with past Helicobacter pylori infection, color difference at the atrophic border was greater with LCI (21.58 ± 6.97 and 27.34 ± 10.32, respectively) than with WLI [14.42 ± 5.95 (p = 0.004) and 17.9 ± 8.48 (p<0.001)]; in those never infected with Helicobacter pylori, color difference at the fundic/pyloric mucosal border was greater with LCI than with WLI (p<0.001). Because of its enhancement of atrophic border detection, we recommend linked color imaging as the method of choice for transnasal endoscopy in health check-ups, particularly for identifying people at high risk of gastric cancer.

Efficacy of a Third-Generation High-Vision Ultrathin Endoscope for Evaluating Gastric Atrophy and Intestinal Metaplasia in Helicobacter pylori-Eradicated Patients

BACKGROUND

Image-enhanced endoscopy methods such as narrow-band imaging (NBI) are advantageous over white-light imaging (WLI) for detecting gastric atrophy, intestinal metaplasia, and cancer. Although new third-generation high-vision ultrathin endoscopes improve image quality and resolution over second-generation endoscopes, it is unclear whether the former also enhances color differences surrounding atrophy and intestinal metaplasia for endoscopic detection. We compared the efficacy of a new third-generation ultrathin endoscope and an older second-generation endoscope.

METHODS

We enrolled 50 Helicobacter pylori-eradicated patients who underwent transnasal endoscopy with a second-generation and third-generation endoscope (GIF-290N and GIF-1200N, respectively) in our retrospective study. Color differences based on the International Commission on Illumination 1976 (L*, a*, b*) color space were compared between second-generation and third-generation high-vision endoscopes.

RESULTS

Color differences surrounding atrophy produced by NBI on the GIF-1200N endoscope were significantly greater than those on GIF-290N (19.2 ± 8.5 vs. 14.4 ± 6.2, p = 0.001). In contrast, color differences surrounding intestinal metaplasia using both WLI and NBI were similar on GIF-1200N and GIF-290N endoscopes. NBI was advantageous over WLI for detecting intestinal metaplasia on both endoscopes.

CONCLUSIONS

NBI using a third-generation ultrathin endoscope produced significantly greater color differences surrounding atrophy and intestinal metaplasia in H. pylori-eradicated patients compared with WLI.

The role of advanced endoscopy in the management of inflammatory digestive diseases (upper gastrointestinal tract)

The Japan Gastroenterological Endoscopy Society held four serial symposia between 2019 and 2020 on the state-of-the-art of issues related to upper GI inflammatory diseases. This review discusses some of the topics addressed in these symposia. The papers regarding nonerosive reflux disease, recent improvements in intraesophageal pH-impedance monitoring and endoscopic diagnosis using image-enhanced endoscopy have been published. Many publications have addressed its usefulness in endoscopic treatment of gastroesophageal reflux disease such as anti-reflux mucosectomy. In the management of eosinophilic esophagitis, since the symptoms are subjective, objective indicators have been sought, and ultrasonography and high-resolution manometry may be useful tools for evaluation. The natural course of this condition, especially of asymptomatic cases, is not well clarified. Some newly developed anti-acid or anti-inflammatory medicines are now under investigation. With regard to autoimmune gastritis, because of widespread medical examinations, diagnosis of asymptomatic cases has been increasing. Recently, its endoscopic characteristics have become clear and the natural history of these conditions is being elucidated. The Kyoto Classification of Gastritis has been reported to be useful not only for Helicobacter pylori diagnosis but also for identification of risks of gastric cancer. Its usefulness is now recognized in Asia and Europe.

Gastric Xanthoma Is Related to the Rapid Growth of Gastric Cancer

Early detection of gastric cancer is important. However, rapid growth of gastric cancers that cannot be resected endoscopically occurs even with periodic check-ups. Accordingly, we assessed factors associated with the speed of gastric cancer growth by examining historical endoscopic images. A total of 1996 gastric cancer cases were screened, and characteristics of lesions with slow and rapid growth were assessed. A total of 114 lesions from 114 patients were included in the assessment. Sixty slow-growing and fifty-four rapidly growing gastric cancers were compared. Female sex and incidence of lesions in the lower part of the stomach were significantly less frequent in the rapid-growth group than in the slow-growth group. History of endoscopic treatment tended to be more frequent in the rapid-growth group. Age, body mass index, histology, Helicobacter pylori status, and medications did not differ significantly between groups. Xanthoma was significantly related to rapid growth of gastric cancer, and map-like redness tended to be more frequent in the rapid-growth group in univariate analysis. Xanthoma was significantly related to rapid growth of gastric cancer on multivariate analysis. Further studies are warranted to clarify the pathophysiological mechanisms involved in the speed of gastric cancer growth.

Helicobacter pylori eradication: Exploring its impacts on the gastric mucosa

Helicobacter pylori (H. pylori) infects approximately 50% of all humans globally. Persistent H. pylori infection causes multiple gastric and extragastric diseases, indicating the importance of early diagnosis and timely treatment. H. pylori eradication produces dramatic changes in the gastric mucosa, resulting in restored function. Consequently, to better understand the importance of H. pylori eradication and clarify the subsequent recovery of gastric mucosal functions after eradication, we summarize histological, endoscopic, and gastric microbiota changes to assess the therapeutic effects on the gastric mucosa.

Improved Visibility of Early Gastric Cancer after Successful Helicobacter pylori Eradication with Image-Enhanced Endoscopy: A Multi-Institutional Study Using Video Clips

The visibility and diagnostic accuracy of early gastric cancer (EGC) after Helicobacter pylori (HP) eradication have been reported to improve using image-enhanced endoscopy (IEE) compared with white light imaging (WLI). The present study clarified the appropriate IEE for the detection and diagnosis of EGC in clinical settings. This prospective and cross-sectional study evaluated the visibility of EGC and endoscopic findings of gastric mucosa after successful HP eradication (n = 31) using videos with WLI and IEE. Three endoscopists evaluated high-definition videos in a randomized order. The mean visibility scores (MVSs) on linked color imaging (LCI) for atrophic border, intestinal metaplasia, map-like redness, and EGC were the highest among each modality (3.87 ± 0.34, 3.82 ± 0.49, 3.87 ± 0.50, and 3.35 ± 0.92, respectively). The MVSs with blue laser imaging (BLI) were highest for magnifying view of the demarcation line (DL), microsurface pattern (MSP), and microvascular pattern (MVP) for EGC (3.77 ± 0.49, 3.94 ± 0.25, and 3.92 ± 0.34, respectively). LCI had the highest visibility among findings of gastric mucosa and EGC after HP eradication, and BLI had the highest visibility of MVP, MSP, and DL in magnifying observation. These results suggest that LCI observation in the entire stomach and further magnifying BLI are the best methods for detecting and diagnosing EGCs after HP eradication, respectively.

Diagnosis of Helicobacter pylori Infection by the Arrangement of Collecting Venules Using White Light Endoscopy: Evaluation of Interobserver Agreement

BACKGROUND

Regular arrangement of collecting venules (RAC) in gastric mucosa accurately identifies patients without Helicobacter pylori (H pylori) infection. The aim of our study was to evaluate the reproducibility of RAC using white light endoscopy without magnification, in a European country, and to assess the impact of proton pump inhibitors (PPIs).

METHODS

A multicenter prospective study with image capture of the distal lesser gastric curvature and gastric biopsies was performed. The presence of starfish-like minute points regularly distributed throughout lesser curvature was considered as RAC positive (RAC+). A set of 20 images was used for the training phase and inter and intra-observer agreements were calculated.

RESULTS

174 patients were included and 85 (48.9%) were taking PPIs. Kappa values for interobserver and intra-observer agreements were substantial (0.786) and excellent (0.906), respectively. H. pylori infection was diagnosed in 29 patients (16.7%): 10/85 with PPIs and 19/89 without PPIs (11.8% vs. 21.3%; p = 0.09). All RAC + patients were free of H. pylori infection, with a sensitivity and negative predictive value of 100%, regardless of PPI intake.

CONCLUSION

The endoscopic diagnosis of H. pylori by RAC is an easy-to-learn and highly reproducible technique, even with PPI intake. Our results warrant RAC as a real-time diagnostic method for H. pylori-negative infection in Western practice.

Differentiation Between Malignant and Benign Endoscopic Images of Gastric Ulcers Using Deep Learning

Background and Aim

Endoscopic differentiation between malignant and benign gastric ulcers (GU) affects further evaluation and prognosis. The aim of our study was to evaluate a deep learning algorithm for discrimination between benign and malignant GU in a database of endoscopic ulcer images.

Methods

We retrospectively collected consecutive upper gastrointestinal endoscopy images of GU performed between 2011 and 2019 at the Sheba Medical Center. All ulcers had a corresponding histopathology result of either benign peptic ulcer or gastric adenocarcinoma. A convolutional neural network (CNN) was trained to classify the images into either benign or malignant. Endoscopies from 2011 to 2017 were used for training (2011-2015) and validation (2016-2017). Hyper-parameters, image augmentation and pre-training on Google images obtained images were evaluated on the validation data. Held-out data from 2018 to 2019 was used for testing the final model.

Results

Overall, the Sheba dataset included 1978 GU images; 1894 images from benign GU and 84 images of malignant ulcers. The final CNN model showed an AUC 0.91 (95% CI 0.85-0.96) for detecting malignant ulcers. For cut-off probability 0.5, the network showed a sensitivity of 92% and specificity of 75% for malignant ulcers.

Conclusion

Our study displays the applicability of a CNN model for automated evaluation of gastric ulcers images for malignant potential. Following further research, the algorithm may improve accuracy of differentiating benign from malignant ulcers during endoscopies and assist in patients' stratification, allowing accelerated patients management and individualized approach towards surveillance endoscopy.

Efficacy of Texture and Color Enhancement Imaging in visualizing gastric mucosal atrophy and gastric neoplasms

In 2020, Olympus Medical Systems Corporation introduced the Texture and Color Enhancement Imaging (TXI) as a new image-enhanced endoscopy. This study aimed to evaluate the visibility of neoplasms and mucosal atrophy in the upper gastrointestinal tract through TXI. We evaluated 72 and 60 images of 12 gastric neoplasms and 20 gastric atrophic/nonatrophic mucosa, respectively. The visibility of gastric mucosal atrophy and gastric neoplasm was assessed by six endoscopists using a previously reported visibility scale (1 = poor to 4 = excellent). Color differences between gastric mucosal atrophy and nonatrophic mucosa and between gastric neoplasm and adjacent areas were assessed using the International Commission on Illumination L*a*b* color space system. The visibility of mucosal atrophy and gastric neoplasm was significantly improved in TXI mode 1 compared with that in white-light imaging (WLI) (visibility score: 3.8 ± 0.5 vs. 2.8 ± 0.9, p < 0.01 for mucosal atrophy; visibility score: 2.8 ± 1.0 vs. 2.0 ± 0.9, p < 0.01 for gastric neoplasm). Regarding gastric atrophic and nonatrophic mucosae, TXI mode 1 had a significantly greater color difference than WLI (color differences: 14.2 ± 8.0 vs. 8.7 ± 4.2, respectively, p < 0.01). TXI may be a useful observation modality in the endoscopic screening of the upper gastrointestinal tract.

Exploration of endoscopic findings and risk factors of early gastric cancer after eradication of Helicobacter pylori

AIM

To explore the endoscopic features and risk factors of early gastric cancer (EGC) after eradication of Helicobacter pylori (H. pylori).

METHODS

A total of 1961 patients who underwent esophago-gastro-duodenoscopy (EGD) with a history of successful H. pylori eradication were enrolled in this multicenter research. Among them, 162 EGC lesions of 132 patients were detected. The endoscopic features and risk factors of post-eradication EGC were explored.

RESULTS

Severe atrophy (75.3% vs. 16.7%, p value <.01), intestinal metaplasia (96.3% vs. 77.1%, p value <.01), map-like redness (89.5% vs. 65.4%, p value <.01), distinct intermediate zone (IZ) (68.5% vs. 23.4%, p value <.01) and xanthoma (58.0% vs. 17.9%, p value <.01) were significantly more frequent in the CA group (patients with newly detected EGC after eradication of H. pylori) than in the NC group (patients without gastric cancer after eradication of H. pylori). In multivariate analysis, severe atrophy (odds ratio (OR) = 8.08; 95% confidence interval (CI), 3.43-20.0; p value<.01), map-like redness (OR = 1.75; 95% CI, 0.11-5.25; p value = .04), distinct IZ (OR = 2.87; 95% CI, 1.20-6.93; p value = .02) and xanthoma (OR = 2.84; 95% CI, 1.20-7.03; p value=.02) were proved to be risk factors for detection of EGC after eradication of H. pylori.

CONCLUSIONS

Severe atrophy and map-like redness and distinct IZ and xanthoma are risk factors of EGC after eradication of H. pylori.

Precision Medicine Approaches to Prevent Gastric Cancer

Gastric cancer remains one of the most common causes of cancer-related death worldwide, although the incidence is declining gradually. The primary risk factor for gastric cancer is Helicobacter pylori infection. The Kyoto global consensus report recommends eradication of H. pylori in all infected patients. However, because it is difficult to stratify the risk of carcinogenesis among patients with a history of H. pylori infection, annual endoscopic surveillance is performed for everyone after eradication. This review summarizes the current approaches used to screen for novel molecules that could assist in the diagnosis of gastric cancer and reduce mortality. Most well-studied molecules are tissue protein biomarkers expressed by the gastric epithelium and associated with metaplasia-dysplasia-carcinoma sequences. Other strategies focus on the origin of cancer stem cell-related markers, such as CD44, and immune reaction-related markers, such as matrix metallopeptidases. Noninvasive methods such as blood-based approaches are more attractive. Serum pepsinogen levels predict the severity of gastric mucosal atrophy before H. pylori eradication, whereas plasma ghrelin levels are associated with atrophy even after eradication. Cell-free DNAs and RNAs are attractive tools for the early detection of cancer. These ideas could lead to the development of more personalized strategies for cancer prevention based on cutting-edge technologies.

The endoscopic predictors of Helicobacter pylori status: a meta-analysis of diagnostic performance

Objective:

The endoscopic findings associated with Helicobacter pylori–naïve status, current infection or past infection are an area of ongoing interest. Previous studies have investigated parameters with a potential diagnostic value. The aim of this study was to perform meta-analysis of the available literature to validate the diagnostic accuracy of mucosal features proposed in the Kyoto classification.

Data sources:

The databases of MEDLINE and Embase, clinicalTrials.gov and the Cochrane Library were systematically searched for relevant studies from October 1999 to October 2019.

Methods:

A bivariate random effects model was used to produce pooled diagnostic accuracy calculations for each of the studied endoscopic findings. Diagnostic odds ratios and sensitivity and specificity characteristics were calculated to identify significant predictors of H pylori status.

Results:

Meta-analysis included 4380 patients in 15 studies. The most significant predictor of an H pylori-naïve status was a regular arrangement of collecting venules (diagnostic odds ratio 55.0, sensitivity 78.3%, specificity 93.8%). Predictors of active H pylori infection were mucosal oedema (18.1, 63.7%, 91.1%) and diffuse redness (14.4, 66.5%, 89.0%). Map-like redness had high specificity for previous H pylori eradication (99.0%), but poor specificity (13.0%).

Conclusion:

The regular arrangement of collecting venules, mucosal oedema, diffuse redness and map-like redness are important endoscopic findings for determining H pylori status. This meta-analysis provides a tentative basis for developing future endoscopic classification systems.

Review: Diagnosis of Helicobacter pylori infection

New imaging techniques are still the topic of many evaluations for both the diagnosis of Helicobacter pylori gastritis and the detection of early gastric cancer. Concerning invasive tests, there were studies on the reuse of the rapid urease test material for other tests, and a novel fluorescent method to be used for histology but with limited sensitivity. Progress occurred essentially in the molecular methods area, especially next-generation sequencing which is applied to detect both H pylori and the mutations associated with antibiotic resistance. For non-invasive tests, a few studies have been published on the validity of breath collection bags, the shortening of the testing time, the performance of different analysers or the added value of citric acid in the protocol. The accuracy of serological immunochromatographic tests is also improving. Multiplex serology detecting antibodies to certain proteins allows confirmation of a current infection. Dried blood spots can be used to collect and store blood without a loss of accuracy. Finally, the serum antibody titer can be useful in predicting the risk of gastric cancer. Several stool antigen tests were evaluated with good results, and a novel test using immunomagnetic beads coated with monoclonal antibodies is potentially interesting. PCR detection in stools can also be effective but needs an efficient DNA extraction method. The use of easyMAG^® (bioMérieux) combined with Amplidiag® H pylori + ClariR (Mobidiag) appears to be powerful.

Comparison of endoscopic visibility and miss rate for early gastric cancers after Helicobacter pylori eradication with white-light imaging versus linked color imaging

BACKGROUND AND AIM

We aimed to investigate whether linked color imaging (LCI) improves endoscopic visibility of early gastric cancers (EGC) after Helicobacter pylori eradication, which are often difficult to detect, and reduces the miss rate when compared with white-light imaging (WLI).

METHODS

The visibility study used two images, one each with WLI and LCI, from 84 consecutive EGC after H. pylori eradication. Endoscopic visibility was evaluated using a visibility score and color difference (CD) value. To analyze miss rates, we studied a library of recorded videos using both WLI and LCI for 70 other consecutive patients after H. pylori eradication, among whom 19 had EGC. Endoscopic screening was done using the same protocol to map the entire stomach. Six endoscopists reviewed the videos in a randomized order. Miss rates of EGC were compared among the modalities.

RESULTS

Mean [(±standard deviation) visibility scores with LCI were significantly higher than those with WLI (3.19 ± 0.84 vs 2.52 ± 0.98, P < 0.001), as were mean CD values (26.3 ± 9.1 vs 13.6 ± 6.3, P < 0.001). Miss rates of the six endoscopists were significantly lower with LCI than with WLI (30.7% vs 64.9%, P < 0.001). Both expert and trainee endoscopists had significantly better results with LCI than with WLI.

CONCLUSIONS

Linked color imaging significantly improved the visibility of EGC after H. pylori eradication compared with WLI using both subjective and objective criteria. Furthermore, LCI significantly reduced miss rates of these lesions compared with WLI.

RGB Pixel Brightness Characteristics of Linked Color Imaging in Early Gastric Cancer: A Pilot Study

Background and Aims

Linked color imaging (LCI) helps screen and diagnose for early gastric cancer by color contrast in different mucosa. RGB (red, green, and blue) pixel brightness quantifies colors, which is relatively objective. Limited studies have combined LCI images with RGB to help screen for early gastric cancer (EGC). We aimed to evaluate the RGB pixel brightness characteristics of EGC and noncancer areas in LCI images.

Methods

We retrospectively reviewed early gastric cancer (EGC) patients and LCI images. All pictures were evaluated by at least two endoscopic physicians. RGB pixel brightness analysis of LCI images was performed in MATLAB software to compare the cancer with noncancer areas. Receiver operating characteristic (ROC) curve was analyzed for sensitivity, specificity, cut-off, and area under the curve (AUC).

Results

Overall, 38 early gastric cancer patients were enrolled with 38 LCI images. Pixel brightness of red, green, and blue in cancer was remarkably higher than those in noncancer areas (190.24 ± 37.10 vs. 160.00 ± 40.35, p < 0.001; 117.96 ± 33.91 vs. 105.33 ± 30.01, p = 0.039; 114.36 ± 34.88 vs. 90.93 ± 30.14, p < 0.001, respectively). Helicobacter plyori (Hp) infection was not relevant to RGB distribution of EGC. Whether the score of Kyoto Classification of Gastritis (KCG) is ≥4 or <4, the pixel brightness of red, green, and blue was not disturbed in both cancer and noncancer (p > 0.05). Receiver operating characteristic (ROC) curve for differentiating cancer from noncancer was calculated. The maximum area under the curve (AUC) was 0.767 in B/G, with a sensitivity of 0.605, a specificity of 0.921, and a cut-off of 0.97.

Conclusions

RGB pixel brightness was useful and more objective in distinguishing early gastric cancer for LCI images.

Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis

Recent advances in endoscopic technology allow detailed observation of the gastric mucosa. Today, endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori (H. pylori) infection and evaluate gastric cancer risk. In 2013, the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification, a new grading system for endoscopic gastritis. The Kyoto classification organized endoscopic findings related to H. pylori infection. The Kyoto classification score is the sum of scores for five endoscopic findings (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness with or without regular arrangement of collecting venules) and ranges from 0 to 8. Atrophy, intestinal metaplasia, enlarged folds, and nodularity contribute to gastric cancer risk. Diffuse redness and regular arrangement of collecting venules are related to H. pylori infection status. In subjects without a history of H. pylori eradication, the infection rates in those with Kyoto scores of 0, 1, and ≥ 2 were 1.5%, 45%, and 82%, respectively. A Kyoto classification score of 0 indicates no H. pylori infection. A Kyoto classification score of 2 or more indicates H. pylori infection. Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8, respectively. A Kyoto classification score of 4 or more might indicate gastric cancer risk.

Can image-enhanced endoscopy improve the diagnosis of Kyoto classification of gastritis in the clinical setting?

Endoscopic diagnosis of Helicobacter pylori (H. pylori) infection, the most common cause of gastric cancer, is very important to clarify high-risk patients of gastric cancer for reducing morbidity and mortality of gastric cancer. Recently, the Kyoto classification of gastritis was developed based on the endoscopic characteristics of H. pylori infection-associated gastritis for clarifying H. pylori infection status and evaluating risk factors of gastric cancer. Recently, magnifying endoscopy with narrow-band imaging (NBI) has reported benefits of the accuracy and reproducibility of endoscopic diagnosis for H. pylori-related premalignant lesions. In addition to NBI, various types of image-enhanced endoscopies (IEEs) are available including autofluorescence imaging, blue laser imaging, and linked color imaging. This review focuses on understanding the clinical applications and the corresponding evidences shown to improve the diagnosis of gastritis based on Kyoto classification using currently available advanced technologies of IEEs.

Linked color imaging for the detection of early gastrointestinal neoplasms

In routine upper and lower gastrointestinal endoscopy, overlooking neoplastic lesions is inevitable even for well-trained endoscopists. Various methods have been reported to improve the detection of gastrointestinal neoplasms including chromoendoscopy, special endoscopes, and processor and image enhanced technologies. Equipment-based image enhanced endoscopy (e-IEE) using narrow band imaging (NBI) and blue laser imaging (BLI) is useful to characterize known lesions with magnification at a close-up view. However, they are not useful for the early detection of superficial, pale neoplasms, or both because of the weak image at a distant view in a wide lumen such as the stomach or colon. Linked color imaging (LCI) is a novel pre- and post-processing technology developed by Fujifilm Corporation that has sufficient brightness to illuminate a wide lumen. LCI delineates early gastric cancers as orange-red and intestinal metaplasia as purple. LCI improves the adenoma detection rate in the colon and decreases the polyp miss rate. LCI contributes to the detection of superficial lesions throughout the gastrointestinal tract by enhancing the color contrast between the neoplasm and the surrounding mucosa. LCI can distinguish them by their specific color allocation based mainly on the distribution of capillaries. The authors believe that moving forward, LCI should be used in routine upper and lower gastrointestinal endoscopy.