Endoscopic grading of gastric atrophy on risk assessment of gastric neoplasia: A systematic review and meta-analysis

Endoscopic Grading and Sampling of Gastric Precancerous Lesions: A Comprehensive Literature Review

Gastric cancer remains a disease with an ominous prognosis, while early gastric cancer has a good-to-excellent prognosis, with 5-year survival rates of up to 92.6% after successful endoscopic resection. In this context, the accurate identification of patients with established gastric precancerous lesions, namely chronic atrophic gastritis and intestinal metaplasia, is the first step in a stepwise approach to minimize cancer risk. Although current guidelines advocate for the execution of random biopsies to stage the extent and severity of gastritis/intestinal metaplasia, modern biopsy protocols are still imperfect as they have limited reproducibility and are susceptible to sampling error. The advent of novel imaging-enhancing modalities, i.e., high-definition with virtual chromoendoscopy (CE), has revolutionized the inspection of gastric mucosa, leading to an endoscopy-based staging strategy for the management of these premalignant changes in the stomach. Nowadays, the incorporation of CE-targeted biopsies in everyday clinical practice offers not only the robust detection of premalignant lesions but also an improvement in quality, by reducing missed diagnoses along with mean biopsies and, thus, the procedural costs and the environmental footprint. In this review, we summarize the recent evidence regarding the endoscopic grading and sampling of gastric precancerous lesions.

The endoscopic model for gastric carcinogenesis and Helicobacter pylori infection: A potential visual mind-map during gastroscopy examination

Helicobacter pylori (Hp) is the main trigger of chronic gastric atrophy and the main leading cause of gastric cancer. Hp infects the normal gastric mucosa and can lead to chronic inflammation, glandular atrophy, intestinal metaplasia, dysplasia and finally adenocarcinoma. Chronic inflammation and gastric atrophy associated with Hp infection appear initially in the distal part of the stomach (the antrum) before progressing to the proximal part (the corpus-fundus). In recent years, endoscopic developments have allowed for the characterization of various gastric conditions including the normal mucosa (pyloric/fundic gland pattern and regular arrangement of collecting venules), Hp-related gastritis (Kyoto classification), glandular atrophy (Kimura-Takemoto classification), intestinal metaplasia (Endoscopic Grading of Gastric Intestinal Metaplasia), and dysplasia/adenocarcinoma (Vessel plus Surface classification). Despite being independent classifications, all these scales can be integrated into a single model: the endoscopic model for gastric carcinogenesis. This model would assist endoscopists in comprehending the process of gastric carcinogenesis and conducting a systematic examination during gastroscopy. Having this model in mind would enable endoscopists to promptly recognize the implications of Hp infection and the potential patient's risk of developing gastric cancer.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Gastric cancer incidence based on endoscopic Kyoto classification of gastritis

BACKGROUND

Gastric cancer (GC) incidence based on the endoscopic Kyoto classification of gastritis has not been systematically investigated using time-to-event analysis.

AIM

To examine GC incidence in an endoscopic surveillance cohort.

METHODS

This study was retrospectively conducted at the Toyoshima Endoscopy Clinic. Patients who underwent two or more esophagogastroduodenoscopies were enrolled. GC incidence was based on Kyoto classification scores, such as atrophy, intestinal metaplasia (IM), enlarged folds (EFs), nodularity, diffuse redness (DR), and total Kyoto scores. Hazard ratios (HRs) adjusted for age and sex were calculated using a Cox hazard model.

RESULTS

A total of 6718 patients were enrolled (median age 54.0 years; men 44.2%). During the follow-up period (max 5.02 years; median 2.56 years), GC developed in 34 patients. The average frequency of GCs per year was 0.19%. Kyoto atrophy scores 1 [HR with score 0 as reference: 3.66, 95% confidence interval (CI): 1.06 to 12.61], 2 (11.60, 3.82-35.27), IM score 2 (9.92, 4.37-22.54), EF score 1 (4.03, 1.63-9.96), DR scores 1 (6.22, 2.65-14.56), and 2 (10.01, 3.73-26.86) were associated with GC incidence, whereas nodularity scores were not. The total Kyoto scores of 4 (HR with total Kyoto scores 0-1 as reference: 6.23, 95%CI: 1.93 to 20.13, P = 0.002) and 5-8 (16.45, 6.29-43.03, P < 0.001) were more likely to develop GC, whereas the total Kyoto scores 2-3 were not. The HR of the total Kyoto score for developing GC per 1 rank was 1.75 (95%CI: 1.46 to 2.09, P < 0.001).

CONCLUSION

A high total Kyoto score (≥ 4) was associated with GC incidence. The endoscopy-based diagnosis of gastritis can stratify GC risk.

Gastroscopy after positive screening for faecal immunochemical tests and colonoscopy: A systematic review

BACKGROUND

Colorectal cancer (CRC) screening using the faecal immunochemical test (FIT) kits based on the detection of occult blood in stool is widely advocated in numerous screening programs worldwide. However, CRC is not commonly diagnosed in positive cases. We undertook this review to determine if there is evidence to suggest the use of opportunistic oesophago-gastro-duodenoscopy (OGD) in patients without CRC.

METHODS

A systematic review encompassing three electronic databases was performed. All peer-reviewed studies of FIT-positive patients who underwent either OGD and colonoscopy concurrently or OGD post-colonoscopy were included. Only studies from 2008 to 2022 using FIT kits were included to ensure studies not previously included in an earlier review were being analysed. A forward citation search of the included articles was also conducted to ensure no relevant articles were missed.

RESULTS

A total of 2409 records were extracted. Only four studies fulfilled the selection criteria and were included. Although the rates of abnormal OGD results were relatively high in the four studies, only 3 of 605 (0.50%) patients had gastric cancer in the entire review sample. No other malignancies were identified in all four studies. Other notable pathologies such as gastric polyps and gastritis were also reported.

CONCLUSIONS

There is little overall evidence to recommend UGI screening for all FIT-positive patients following a colonoscopy. However, there may be a role for clinicians to consider opportunistic OGD in this group of patients. Future research should examine patient populations from other sociocultural contexts including cost-effective analysis when considering changes in health guidelines on UGI screening.

Characteristics of different types of Helicobacter pylori: New evidence from non-amplified white light endoscopy

Background

Different types of Helicobacter pylori (H. pylori) were analyzed to determine their infection characteristics using serology, pathology, and non-magnification white light endoscopy combined with the Kimura-Takemoto classification, and the regular arrangement of collecting venules (RAC) as well.

Materials and methods

A retrospective analysis of 685 inpatients who have completed the ¹⁴C-urea breath test, the H. pylori antibody typing classification, the serum gastric function tests (PGI/PGII/G-17), the endoscope detection, and the pathological examinations.

Results

The levels of PGI, PGII, and G-17 were in descending order from the type I H. pylori infection group to the type II H. pylori infection group than the control group (F = 14.31; 26.23; 9.12, P < 0.01). Using the Kimura-Takemoto classification, there were significant differences among the three groups of different degrees of atrophy ( χ 2 =29.81; 482.78; 292.5, P< 0.01). Based on the characteristics of RAC, the H. pylori infection rates were in descending order from the type I H. pylori infection group to the type II H. pylori infection group than the control group ( χ 2 = 200.39; 174.72; 143.51, P < 0.01). The type I H. pylori infection group had higher grades than those of the type II H. pylori infection group in the OLGA and OLGIM staging systems, while the differences are statistically significant only in the OLGA staging system ( χ 2 =10.63, P < 0.05).

Conclusion

With the aid of non-amplified white light endoscopy, we found new evidence of type I H. pylori infection accelerating the progression of gastric mucosal atrophy through the degree of atrophy and the range of infection, whereas type II H. pylori infection has a low ability of migration and atrophy progression. Individual virulence factor-based eradication therapy may be a better choice in future.

Diverse contributions of the visceral fat area to the etiology of two distinct subtypes of esophago-gastric junctional adenocarcinoma

BACKGROUND

There are two distinct etiologies of esophago-gastric junctional adenocarcinomas (EGJACs): one associated with extensive gastric mucosal atrophy (GA), resembling non-cardiac gastric cancers; and the other related to gastro-esophageal reflux disease, resembling esophageal adenocarcinoma. In this study, we investigated the associations between the visceral fat area (VFA) and EGJACs separately in the two subtypes of EGJACs, depending on the extent of background GA.

METHODS

Sixty-four consecutive patients with EGJACs (Siewert type 2) were enrolled from a population-based database in Akita Prefecture, Japan, between 2014 and 2019. Two age- and sex-matched healthy controls were randomly assigned to each EGJAC case. The extents of GA were evaluated endoscopically, and the VFA values were measured based on computed tomography images. Logistic regression analyses were performed to investigate the associations between EGJACs and the VFA.

RESULTS

Study subjects were classified into 2 subgroups depending on the extent of endoscopic GA: 29 (45.3%) without and 35 (54.7%) with extensive GA. Multivariable regression analyses revealed that a VFA of ≥100 cm² was significantly associated with EGJACs in subjects without extensive GA [odds ratio (95% confidence interval): 2.65 (1.08-6.54)], while there was no such association in subjects with extensive GA [odds ratio (95% confidence interval): 1.52 (0.60-3.83)].

CONCLUSIONS

The contribution of the VFA to the etiology of EGJACs seems to differ depending on the extent of background GA, with the VFA more prominently associated with EGJACs in subjects without extensive GA than in those with it, providing further rationale concerning the heterogeneous nature of EGJAC etiology.

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.

Identification of serum microRNAs as potential diagnostic biomarkers for detecting precancerous lesions of gastric cancer

Aim

Gastric mucosal changes associated with chronic gastritis are known to be precancerous lesions of gastric cancer. We aimed to identify individuals with a high risk of gastric cancer by detection of microRNAs (miRNA) in the blood as biomarkers.

Methods

Of 1206 individuals screened, 144 who were positive for Helicobacter pylori (H. pylori) by the serum antibody test and who underwent endoscopy were the subjects of this study. For the gross assessment of mucosal inflammation, we applied the Kimura-Takemoto classification, in which normal mucosa was defined as grade 0, and atrophy was categorized as grade 1 (C-1 and C-2), grade 2 (C-3 and O-1), and grade 3 (O-2 and O-3). Serum samples were divided into two phases and used for miRNA microarray profiling. We compared the expression of miRNAs in grade 3 mucosa and other grades. Expression in gastric cancer was confirmed with TCGA data.

Results

miR-196b-3p was significantly upregulated, and miR-92a-2-5p was downregulated (P < .05 and q < 0.2). TCGA data showed a high expression of miR-196b-3p in gastric cancer cases (P < .001). Comparing grade 3 and the others, the area under the receiver operating characteristic curve using the detected miRNAs was as high as about 0.7. Furthermore, the combination of miRNAs resulted in higher accuracy. In terms of the significance of the combinatory mRNAs, the combination of three miRNAs (miR-196b-3p, miR-92a-2-5p, and miR-6791-3p) revealed high sensitivity and specificity, with the area under the curve exceeding 0.8.

Conclusion

The identified combinatory miRNAs may represent promising biomarkers of precancerous lesions in gastric cancer.

Kimura-Takemoto Classification: A Tool to Predict Gastric Intestinal Metaplasia Progression to Advanced Gastric Neoplasia

BACKGROUND AND AIMS

Gastric cancer is a leading cause of morbidity and mortality worldwide. Gastric intestinal metaplasia (GIM) has been described as a key histologic step in the development of gastric adenocarcinoma. However, not all people with GIM develop malignancy. We studied the factors associated with progression to dysplasia and advanced gastric neoplasia (aGN) in patients with baseline GIM.

METHODS

Retrospective cohort analysis of patients with baseline GIM and subsequent endoscopic evaluation at Cleveland Clinic Florida and Ohio Main Campus between 2005 and 2017. Demographic and exposure risk factors, as well as Kimura-Takemoto classification (KTc), were used as variables for hazards ratio (HR) and Kaplan-Meier survival-free analysis for aGN and any form of dysplasia progression.

RESULTS

There were 708 patients identified with GIM; 29 patients (4.1%) progressed to any degree of dysplasia. From these, LGD was present in 12 cases (1.7%), HGD in 4 cases (0.6%), and gastric cancer in 13 cases (1.8%), for a total of 17 aGN cases. KTc was associated with dysplasia and aGN progression (p < 0.001), and no cases progressed if KTc findings were absent. Open-type KTc was associated with aGN (HR 6.36, p < 0.001) and any dysplasia progression (HR 13.34, p < 0.001) compared to closed-type or absent KTc features. No other factors were associated with aGN or dysplasia progression. Open-type KTc was also associated with shorter cancer survival-free progression.

CONCLUSION

Patients with baseline GIM present a higher progression risk to aGN, dysplasia, or cancer if concomitant KTc findings are present, particularly an open-type KTc pattern.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Pyloric Incompetence Associated with Helicobactor pylori Infection and Correlated to the Severity of Atrophic Gastritis

Duodenogastric reflux (DGR) causes bile reflux gastritis (BRG) and may develop into gastric cancer. DGR is classified as primary in non-operated stomachs or secondary to surgical intervention. Primary DGR and Helicobacter pylori (H. pylori) infection are reportedly related. However, the mechanism is not fully understood. This study aimed to elucidate the relationship between H. pylori infection and pyloric incompetence in a non-operated stomach. A total of 502 non-operated participants who underwent an upper intestinal endoscopy were prospectively enrolled. Endoscopic findings (EAC, endoscopic atrophy classification; nodular gastritis; xanthoma; fundic gland polyp; and incompetence of pylorus), sex, age, gastrin, pepsinogen (PG) I and PG II levels were evaluated. PG I/PG II ratio, anti-H. pylori-Ab positivity, and atrophic gastritis status were significantly different between the normal and incompetent pylori (p = 0.043, <0.001, and 0.001, respectively). Open-type atrophic gastritis was significantly higher in the incompetent pylori. Incompetence of the pylorus and EAC were moderately correlated (Cramer’s V = 0.25). Multivariate analysis revealed that the presence of anti-H. pylori-Ab was the only independent factor associated with the incompetence of the pylorus, with an adjusted odds ratio of 2.70 (95% CI: 1.47−4.94, p = 0.001). In conclusion, pyloric incompetence was associated with H. pylori infection and moderately correlated to the severity of atrophic gastritis in non-operated stomachs.

Diagnostic Accuracy of H. pylori Status by Conventional Endoscopy: Time-Trend Change After Eradication and Impact of Endoscopic Image Quality

Aim

To assess the time trend of diagnostic accuracy of pre- and post-eradication H. pylori status and interobserver agreement of gastric atrophy grading.

Methods

A series 100 of conventional endoscopic image sets taken from subjects undergoing gastric cancer screening at a polyclinic were evaluated by 5 experienced assessors. Each assessor independently examined endoscopic findings according to the Kyoto classification and then determined the H. pylori status (never, current, or past infected). Gastric atrophy was assessed according to the Kimura-Takemoto classification and classified into 3 grades (none/mild, moderate, or severe). The image series that ≥3 assessors considered to have good quality were arbitrarily defined as high-quality image (HQI) series, and the rest were defined as low-quality image (LQI) series.

Results

The overall diagnostic accuracy of H. pylori status was 83.0%. It was lowest in subjects with current infection (54%), gradually increased at 1 year (79%, P < 0.001) and 3 years (94.0%, P = 0.002), but then did not significantly change at 5 years (91.0%, P = 0.420) after eradication. The rate of LQI series was 28%. The overall diagnostic accuracy of H. pylori status dropped from 88.9% to 67.9% (P < 0.001), and the mean kappa value on gastric atrophy grading dropped from 0.730 to 0.580 (P = 0.002) in the HQI and LQI series, respectively.

Conclusions

Diagnostic accuracy of H. pylori status increased over time after eradication. LQI series badly affected the diagnostic accuracy of H. pylori status and the level of agreement when grading gastric atrophy.

Gastritis: The clinico-pathological spectrum

The inflammatory spectrum of gastric diseases includes different clinico-pathological entities, the etiology of which was recently established in the international Kyoto classification. A diagnosis of gastritis combines the information resulting form the gross examination (endoscopy) and histology (microscopy). It is important to consider the anatomical/functional heterogeneity of the gastric mucosa when obtaining representative mucosal biopsy samples. Gastritis includes self-limiting and non-self-limiting (long-standing) inflammatory diseases, and the latter are epidemiologically, biologically and clinically linked to the onset of gastric cancer (i.e. "inflammation-associated cancer"). Different biological models of inflammation-associated gastric oncogenesis have been proposed. Helicobacter pylori (H. pylori) gastritis is the most prevalent worldwide, and H. pylori is classified as a first-class carcinogen. On these bases, eradicating H. pylori is mandatory for the primary prevention of gastric cancer. Non-self-limiting gastritis may also be triggered by the immune-mediated destruction of gastric parietal cells, resulting in autoimmune gastritis. In both H. pylori-related and autoimmune gastritis, the non-self-limiting inflammation results in atrophy of the gastric mucosa, which is the main factor promoting gastric cancer. Long-term follow-up studies consistently demonstrate the prognostic impact of the histological staging of gastritis in gastric cancer secondary prevention strategies.