Operative Link for Gastritis Assessment gastritis staging incorporates intestinal metaplasia subtyping

Practice Trends among US Gastroenterologists following the 2020 American Gastroenterological Association Guidelines on Gastric Intestinal Metaplasia: Data from a Tertiary Care Center

BACKGROUND AND AIMS

Studies show variability in gastroenterologists' management of gastric intestinal metaplasia (GIM) in the United States. In 2020, the American Gastroenterological Association published GIM guidelines, recommending physician-patient shared decision-making on GIM surveillance based on risk factors. We compared gastroenterologists' communication trends of a GIM finding and surveillance recommendations before and after 2020 and evaluated patient and provider factors associated with a surveillance recommendation.

METHODS

A sample of patients diagnosed with GIM on biopsies from upper endoscopies performed in 2018 (cohort A) and 2021 (cohort B) were included. Logistic regression analysis assessed the association between patient/provider characteristics and surveillance recommendations in the overall cohort and over time.

MATERIALS

In all, 347 patients were included: 175 in cohort A and 172 in B. Median age was 65.7 (56.0, 73.4), and 54.5% were females. Communication to patients about GIM findings and surveillance recommendations increased from 24.6% <2020 to 50% >2020 (P<0.001) and 20% <2020 to 41.3% >2020 (P<0.001), respectively. Overall, endoscopy >2020, family history of gastric cancer, autoimmune gastritis, female providers, and gastroenterologists with 10 to 20 years of experience were associated with a surveillance recommendation. The effect of family history of gastric cancer and the effect of the patient's female sex on surveillance was significantly different between both cohorts [Odds ratio (OR): 0.13, 95% (Confidence interval) CI: 0.02, 0.97 and OR 3.39, 95% CI: 1.12, 10.2, respectively).

CONCLUSIONS

Despite a 2-fold increase in surveillance recommendations after 2020, there was no meaningful effect of any of the patients' factors on a recommendation for surveillance over time, which raises the question as to whether surveillance is being offered to both average and high-risk patients without thorough risk stratification.

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.

U-Net deep learning model for endoscopic diagnosis of chronic atrophic gastritis and operative link for gastritis assessment staging: a prospective nested case-control study

Background

The operative link for the gastritis assessment (OLGA) system can objectively reflect the stratification of gastric cancer risk in patients with chronic atrophic gastritis (CAG).

Objectives

We developed a real-time video monitoring model for the endoscopic diagnosis of CAG and OLGA staging based on U-Net deep learning (DL). To further validate and improve its performance, we designed a study to evaluate the diagnostic evaluation indices.

Design

A prospective nested case-control study.

Methods

Our cohort consisted of 1306 patients from 31 July 2021 to 31 January 2022. According to the pathological results, patients in the cohort were divided into the CAG group and the chronic non-atrophic gastritis group to evaluate the diagnostic evaluation indices. Each atrophy lesion was automatically labeled and the atrophy severity was assessed by the model. Propensity score matching was used to minimize selection bias.

Results

The diagnostic evaluation indices and the consistency between OLGA staging and pathological diagnosis of the model were superior to those of endoscopists [sensitivity (89.31% versus 67.56%), specificity (90.46% versus 70.23%), positive predictive value (90.35% versus 69.41%), negative predictive value (89.43% versus 68.40%), accuracy rate (89.89% versus 68.89%), Youden index (79.77% versus 37.79%), odd product (79.23 versus 4.91), positive likelihood ratio (9.36 versus 2.27), negative likelihood ratio (0.12 versus 0.46)], areas under the curves (AUC) (95% CI) (0.919 (0.893-0.945) versus 0.749 (0.707-0.792), p < 0.001) and kappa (0.816 versus 0.291)].

Conclusion

Our study demonstrated that the DL model can assist endoscopists in real-time diagnosis of CAG during gastroscopy and synchronous identification of high-risk OLGA stage (OLGA stages III and IV) patients.

Trial registration

ChiCTR2100044458.

Comparative morphological characteristics of helicobacter pylori and autoimmune gastritis

Objective: to conduct a comparative morphological analysis of helicobacter pylori (H. pylori) and autoimmune gastritis and to determine the significant morphological criteria for differential diagnosis.

Materials and methods. 30 cases of chronic atrophic helicobacter gastritis and 30 cases of chronic atrophic autoimmune gastritis were retrospectively selected for the study. In all cases of helicobacter gastritis, the presence of H. pylori was confirmed by morphological diagnostic methods using Giemsa staining or additionally using immunohistochemistry. All cases of autoimmune gastritis were additionally confirmed by clinical and laboratory diagnostic methods, some patients had a long history of follow-up and biopsy material was taken from them repeatedly. A prerequisite was taking at least 5 biopsies according to the Sydney Protocol.

Results. The main differential diagnostic feature in our study was the detection of H. pylori, as well as the localization of the lesion in the stomach body characteristic of autoimmune gastritis and in the antrum in helicobacter gastritis. The study groups differed by gender (the predominance of females in the group of autoimmune gastritis), the prevalence and activity of inflammation (all cases of helicobacter gastritis had signs of inflammation activity). When studying the content of neuroendo-crine cells in cases of helicobacter gastritis in the stomach body, simple hyperplasia of neuroendocrine cells was noted, in cases of au-toimmune gastritis, the appearance of chains and nodules was noted, which corresponded to linear and nodular hyperplasia of neuro-endocrine cells.

Conclusion. The morphological criteria obtained in the study make it possible to make a differential diagnosis between helicobacter and autoimmune gastritis. This is extremely important because of the differences in treatment approaches and dynamic monitoring tactics in these variants of chronic gastritis.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

Autoimmune Atrophic Gastritis: The Role of miRNA in Relation to Helicobacter Pylori Infection

Introduction

MicroRNAs (miRNAs) have been proposed as diagnostic markers, biomarkers of neoplastic progression, and possible therapeutic targets in several immune-mediated diseases. We aimed to analyze the expression profile of selected miRNAs (miR21, miR142, miR223, miR155) in patients with autoimmune atrophic gastritis (AAG), patients with non-autoimmune multifocal atrophic gastritis (MAG), and healthy control subjects (HC).

Materials and methods

A total of 103 patients with AAG were consecutively recruited for this study among those attending our gastroenterology outpatient clinic. Participating patients were divided into two groups: primary, not Helicobacter pylori (HP)-associated related AAG (n=57, P-AAG) and HP-associated AAG (n=46, HP-AAG); this subgroup included HP-positive patients, patients with previously reported HP infection, and patients harboring antral atrophy, considered as a stigma of HP infection. We also included 20 sex-age-matched MAG patients and 10 HC. Upper endoscopy with gastric biopsies were performed on each AAG and MAG patient. Circulating levels of miR21-5p, miR142-3p, miR223-3p, and miR155-5p were measured by RT-PCR in all groups.

Results

MiR-21 was over-expressed in P-AAG (p=0.02), HP-AAG (p = 0.04), and MAG (p=0.03) compared with HC. By contrast, miR-142 was more expressed in HC than in HP-AAG (p=0.04) and MAG (p=0.03). MiR-155 showed no significant differences among the four subgroups, while, unexpectedly, miR-223 was overexpressed in HC compared to P-AAG (p=0.01), HP-AAG (p=0.003), and MAG (p<0.001), and was higher in P-AAG than in MAG (p=0.05).

Conclusions

MiR-21 was over-expressed in patients with gastric precancerous conditions irrespective of etiology, while in the same subgroups miR-142 and miR-223 were under-expressed compared to healthy controls. Controlling miRNAs up- or downregulation could lead to a breakthrough in treating chronic autoimmune diseases and potentially interfere with the progression to cancer.

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.

Optimization of Alcian blue pH 1.0 histo-staining protocols to match mass spectrometric quantification of sulfomucins and circumvent false positive results due to sialomucins

Sulfomucins are in some body locations and species a normal occurrence, whereas in other situations, are a sign of pathology. Sulfomucin content on histological sections and isolated material is frequently analyzed with Alcian blue staining at pH 1.0. However, since the stain detects the charge, a high density of other charged molecules, such as sialic acids, has potential to impede specificity. Here, we compared the outcome from four staining protocols with the level of sulfation determined by liquid chromatography–tandem mass spectrometric analysis on samples from various tissues with variable sulfation and sialylation levels. We found that a protocol we designed, including rinsing with MetOH and 0.5 M NaCl buffer at pH 1.0, eliminates the false positive staining of tissues outperforming commonly recommended solutions. In tissues with low-to-moderately sulfated mucins (e.g. human stomach and salmonid epithelia), this method enables accurate relative quantification (e.g. sulfate scoring comparisons between healthy and diseased tissues), whereas the range of the method is not suitable for comparisons between tissues with high sulfomucin content (e.g. pig stomach and colon).

Current Helicobacter pylori Diagnostics

The high prevalence of Helicobacter pylori and the variety of gastroduodenal diseases caused by this pathogen necessitate the use of only accurate methods both for the primary diagnosis and for monitoring the eradication effectiveness. There is a broad spectrum of diagnostic methods available for detecting H. pylori. All methods can be classified as invasive or non-invasive. The need for upper endoscopy, different clinical circumstances, sensitivity and specificity, and accessibility defines the method chosen. This article reviews the advantages and disadvantages of the current options and novel developments in diagnostic tests for H. pylori detection. The progress in endoscopic modalities has made it possible not only to diagnose precancerous lesions and early gastric cancer but also to predict H. pylori infection in real time. The contribution of novel endoscopic evaluation technologies in the diagnosis of H. pylori such as visual endoscopy using blue laser imaging (BLI), linked color imaging (LCI), and magnifying endoscopy is discussed. Recent studies have demonstrated the capability of artificial intelligence to predict H. pylori status based on endoscopic images. Non-invasive diagnostic tests such as the urea breathing test and stool antigen test are recommended for primary diagnosis of H. pylori infection. Serology can be used for initial screening and epidemiological studies. The histology showed its value in detecting H. pylori and provided more information about the degree of gastric mucosa inflammation and precancerous lesions. Molecular methods are mainly used in detecting antibiotic resistance of H. pylori. Cultures from gastric biopsies are the gold standard and recommended for antibiotic susceptibility tests.

The Colombian Chemoprevention Trial: 20-Year Follow-Up of a Cohort of Patients With Gastric Precancerous Lesions

BACKGROUND & AIMS

Helicobacter pylori eradication and endoscopic surveillance of gastric precancerous lesions are strategies to reduce gastric cancer (GC) risk. To our knowledge, this study is the longest prospective cohort of an H pylori eradication trial in a Hispanic population.

METHODS

A total of 800 adults with precancerous lesions were randomized to anti-H pylori treatment or placebo. Gastric biopsy samples taken at baseline and 3, 6, 12, 16, and 20 years were assessed by our Correa histopathology score. A generalized linear mixed model with a participant-level random intercept was used to estimate the effect of H pylori status on the score over time. Logistic regression models were used to estimate progression by baseline diagnosis and to estimate GC risk by intestinal metaplasia (IM) subtype and anatomic location.

RESULTS

Overall, 356 individuals completed 20 years of follow-up. Anti-H pylori therapy (intention-to-treat) reduced progression of the Correa score (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.38-0.93). H pylori-negative status had a beneficial effect on the score over time (P = .036). Among individuals with IM (including indefinite for dysplasia) at baseline, incidence rates per 100 person-years were 1.09 (95% CI, 0.85-1.33) for low-grade/high-grade dysplasia and 0.14 (95% CI, 0.06-0.22) for GC. Incomplete-type (vs complete-type) IM at baseline presented higher GC risk (OR, 13.4; 95% CI, 1.8-103.8). Individuals with corpus (vs antrum-restricted) IM showed an OR of 2.1 (95% CI, 0.7-6.6) for GC.

CONCLUSIONS

In a high-GC-risk Hispanic population, anti-H pylori therapy had a long-term beneficial effect against histologic progression. Incomplete IM is a strong predictor of GC risk.

Gastric Intestinal Metaplasia: Demographic and Epidemiological Characterization in Puerto Rican Hispanics (2012-2014)

Background and Aims

Gastric cancer is the 5^th leading cause of cancer mortality worldwide and the leading infection-associated cancer. Helicobacter pylori is the most common chronic bacterial infection in humans and the major predisposing factor for the development of gastric intestinal metaplasia (GIM), the principal preneoplastic lesion in the gastric carcinogenesis pathway. GIM surveillance is now recommended for individuals among high-risk subgroups by three major gastroenterology societies in Europe, England, and U.S. Our objective was to provide the initial epidemiologic data for GIM among Hispanics in Puerto Rico.

Methods

Using a cross-sectional study design, we analyzed an extensive pathology database (n = 43,993) that captured approximately 50% of all endoscopy biopsies taken during 2012-2014 at academic, public, and private sectors in Puerto Rico. Prevalence estimates of GIM, GIM subgroups, and H. pylori status were estimated using logistic regression models.

Results

A total of 4,707 GIM cases were identified during the study period for a prevalence rate of 10.7%. H. pylori was detected in 26.9% (95% CI: 25.7-28.2) of the GIM cases. The majority of the pathology reports lacked information regarding the high-risk subtypes (99.6%) and extension (71.2%).

Conclusions

The prevalence of GIM among Hispanics living in Puerto Rico may be higher than in U.S. mainland non-Hispanic populations. The prevalence of H. pylori detected in our study population was comparable to the rates reported in the mainland U.S. Standardization of the endoscopy biopsy protocol and pathology reporting is needed to characterize and risk stratify GIM surveillance programs in Puerto Rico.

Histological assessment of gastric pseudopyloric metaplasia: Intra- and inter-observer consistency

BACKGROUND

The histological spectrum of oxyntic mucosal atrophy (a major determinant of gastric cancer risk) includes pseudopyloric metaplasia (PPM), which histological assessment has been regarded as unreliable. PPM consistently expresses Trefoil-Factor 2 (TFF2), which is histochemically detecteble (TFF2-IHC).

AIMS

Intra- and inter-observer consistency in assessing PPM was examined using both hematoxylin & eosin (H&E) and TFF2-IHC.

MATERIALS AND METHODS

Seventy-four oxyntic biopsy samples obtained from autoimmune gastritis were considered. Two serial histological sections obtained from the paraffin-embedded tissue-samples were stained with H&E and TFF2-IHC. Three pathologists (Alpha, Beta, Gamma) independently scored PPM by both staining and the Intra- and inter-observer consistency (H&E versus TFF2-IHC) was calculated using k-statistics and/or Spearman's coefficient.

RESULTS

Based on H&E-stain versus TFF2-IHC, intra-observer consistency in PPM assessement was ranked as consistently "good" (k-values: Alpha=0.79; Beta=0.78; Gamma=0.75). Based on H&E, the overall PPM inter-observer consistency among the 3 observers was ranked as "good" (k=0.77) (the inter-observer consistency for pairs of observers was as follows: Alpha versus Beta k=0.88; Alpha versus Gamma k=0.87; Beta versus Gamma k=0.80). Based on TFF2-IHC, the overall PPM inter-observer agreement was ranked as "excellent" (k=0.91) (the inter-observer consistency for pairs of observers was as follows: Alpha versus Beta k=1; Alpha versus Gamma k=0.91; Beta versus Gamma k=0.91).

CONCLUSION

Relying on either H&E staining or TFF2-IHC, pathologists assess PPM consistently.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Diagnosis of Helicobacter pylori infection in clinical practice

Diagnostic tests used to detection Helicobacter pylori are divided into invasive (requiring endoscopy) and non-invasive, direct (bacteriological, histological or molecular detection of the bacterium) and indirect (detection of urease activity of the bacterium or antibodies to it). The choice of the test is determined by the clinical situation, as well as by its availability and cost. The sensitivity of most tests is affected by the use of antisecretory drugs and antibiotics.

Gastritis staging in the endoscopic follow-up for the secondary prevention of gastric cancer: a 5-year prospective study of 1755 patients

OBJECTIVE

Operative link on gastritis assessment (OLGA) staging for gastritis ranks the risk for gastric cancer (GC) in progressive stages (0-IV). This prospective study aimed at quantifying the cancer risk associated with each gastritis stage.

DESIGN

A cohort of 1755 consecutive patients with dyspepsia underwent initial (T-0) oesophagogastroduodenoscopy with mapped gastric biopsies, OLGA staging and assessment of Helicobacter pylori infection. Patients were followed for 55 months (median); patients with stages II III and IV underwent a second endoscopy/restaging (T-1), and those with stages 0 and I were followed clinically and through in-depth clinical and record checking. Endpoints were OLGA stage at T-1 and development of gastric epithelial neoplasia.

RESULTS

At T-0, 77.6% of patients had stage 0, 14.4% stage I, 5.1% stage II, 2.1% stage III and 0.85% stage IV. H. pylori infection was detected in 603 patients at T-0 and successfully eradicated in 602 of them; 220 had a documented history of H. pylori eradication; and 932 were H. pylori naïve-negative. Incident neoplastic lesions (prevalence=0.4%; low-grade intraepithelial neoplasia (IEN)=4; high-grade IEN=1; GC=2) developed exclusively in patients with stages III-IV. The risk for epithelial neoplasia was null in patients at stages 0, I and II (95% CI 0 to 0.4), 36.5 per 1000 person-years in patients at stage III (95% CI 13.7 to 97.4) and 63.1 per 1000 person-years in patients at stage IV (95% CI 20.3 to 195.6).

CONCLUSIONS

This prospective study confirms that OLGA staging reliably predicts the risk for development of gastric epithelial neoplasia. Although no neoplastic lesions arose in H. pylori-naïve patients, the H. pylori eradication in subjects with advanced stages (III-IV) did not abolish the risk for neoplastic progression.

Dynamics of Helicobacter pylori infection as a determinant of progression of gastric precancerous lesions: 16-year follow-up of an eradication trial

OBJECTIVE

To evaluate the long-term effect of cumulative time exposed to Helicobacter pylori infection on the progression of gastric lesions.

DESIGN

795 adults with precancerous gastric lesions were randomised to receive anti-H. pylori treatment at baseline. Gastric biopsies were obtained at baseline and at 3, 6, 12 and 16 years. A total of 456 individuals attended the 16-year visit. Cumulative time of H. pylori exposure was calculated as the number of years infected during follow-up. Multivariable logistic regression models were used to estimate the risk of progression to a more advanced diagnosis (versus no change/regression) as well as gastric cancer risk by intestinal metaplasia (IM) subtype. For a more detailed analysis of progression, we also used a histopathology score assessing both severity and extension of the gastric lesions (range 1-6). The score difference between baseline and 16 years was modelled by generalised linear models.

RESULTS

Individuals who were continuously infected with H. pylori for 16 years had a higher probability of progression to a more advanced diagnosis than those who cleared the infection and remained negative after baseline (p=0.001). Incomplete-type IM was associated with higher risk of progression to cancer than complete-type (OR, 11.3; 95% CI 1.4 to 91.4). The average histopathology score increased by 0.20 units/year (95% CI 0.12 to 0.28) among individuals continuously infected with H. pylori. The effect of cumulative time of infection on progression in the histopathology score was significantly higher for individuals with atrophy (without IM) than for individuals with IM (p<0.001).

CONCLUSIONS

Long-term exposure to H. pylori infection was associated with progression of precancerous lesions. Individuals infected with H. pylori with these lesions may benefit from eradication, particularly those with atrophic gastritis without IM. Incomplete-type IM may be a useful marker for the identification of individuals at higher risk for cancer.

幽门螺杆菌根除治疗在胃癌预防中的现状及前景

幽门螺杆菌(Helicobacter pylori, H. pylori)与胃癌(gastric cancer, GC)发生发展密切相关, 根除H. pylori可降低GC发生率. 经济学分析表明, 在高危人群中根除治疗H. pylori作为预防GC的策略是成本效益较好的. 即使在GC低风险人群中, H. pylori筛查和治疗也能使上消化道其他非恶性疾病获益. 然而, 广泛开展H. pylori根除治疗可能带来其他问题, 包括抗生素耐药增加和与H. pylori负相关疾病(如胃食管反流病、Barrett食管、哮喘和肥胖等)的患病率升高. 本文将结合近年最新研究, 就上述问题展开论述, 进一步提出H. pylori根除治疗预防GC所面临的挑战以及将来可能的进展方向.

Autoimmune gastritis: Pathologist’s viewpoint

Western countries are seeing a constant decline in the incidence of Helicobacter pylori-associated gastritis, coupled with a rising epidemiological and clinical impact of autoimmune gastritis. This latter gastropathy is due to autoimmune aggression targeting parietal cells through a complex interaction of auto-antibodies against the parietal cell proton pump and intrinsic factor, and sensitized T cells. Given the specific target of this aggression, autoimmune gastritis is typically restricted to the gastric corpus-fundus mucosa. In advanced cases, the oxyntic epithelia are replaced by atrophic (and metaplastic) mucosa, creating the phenotypic background in which both gastric neuroendocrine tumors and (intestinal-type) adenocarcinomas may develop. Despite improvements in our understanding of the phenotypic changes or cascades occurring in this autoimmune setting, no reliable biomarkers are available for identifying patients at higher risk of developing a gastric neoplasm. The standardization of autoimmune gastritis histology reports and classifications in diagnostic practice is a prerequisite for implementing definitive secondary prevention strategies based on multidisciplinary diagnostic approaches integrating endoscopy, serology, histology and molecular profiling.

Adenocarcinomas at different positions at the gastro-oesophageal junction show distinct association with gastritis and gastric preneoplastic conditions

OBJECTIVE

Adenocarcinomas at the gastro-oesophageal junction (GOJ) are currently stratified by tumour location. This retrospective study examines the association of preneoplastic conditions and inflammation of the gastric mucosa with GOJ cancer at different locations and compares them with nonjunctional gastric cancers.

PATIENTS AND METHODS

A total of 520 patients with junctional and nonjunctional gastric cancer were assessed for the presence and degree of intestinal metaplasia, glandular atrophy and inflammation in the stomach. Histopathological data were complete for 428 patients (68.9% men, median age 67.7 years), including 172 patients with GOJ cancer (GOJ1: 1-5 cm proximal to the junction, GOJ2: 'true' junctional, GOJ3: 2-5 cm distal to the junction). Gastric inflammation and preneoplastic conditions were scored according to the updated Sydney classification and further stratified into respective operative link on gastritis assessment (OLGA) and operative link on gastritis assessment on intestinal metaplasia (OLGIM) stages.

RESULTS

The prevalence and degree of gastric atrophy and intestinal metaplasia were significantly lower in GOJ1 than GOJ3 (P<0.01). Preneoplastic conditions in the stomach were similar in GOJ3 compared with nonjunctional gastric cancer. GOJ1 were almost exclusively (98.4%) of the intestinal type, whereas GOJ2 and GOJ3 were the diffuse type in 22.6 and 22.4% of the patients (P<0.001). Of all patients, only 8.5 and 12.7% presented with stage III/IV according to OLGA and OLGIM, respectively. However, data for OLGA and OLGIM staging were only available in 61.2 and 67.9% of patients, respectively.

CONCLUSION

GOJ1 are less likely to be associated with gastric pathology compared with GOJ3 or nonjunctional gastric cancer. OLGA or OLGIM staging in patients with advanced gastro-oesophageal cancer seems to be of limited value.

Secondary prevention of epidemic gastric cancer in the model of Helicobacter pylori-associated gastritis

Irrespective of its etiology, long-standing, non-self-limiting gastric inflammation (mostly in Helicobacter pylori-associated cases) is the cancerization ground on which epidemic (intestinal-type) gastric carcinoma (GC) can develop. The natural history of invasive gastric adenocarcinoma encompasses gastritis, atrophic mucosal changes, and intraepithelial neoplasia (IEN). The topography, the extent and the severity of the atrophic changes significantly correlate with the risk of developing both IEN and GC. In recent years, both noninvasive (serological) tests and invasive (endoscopy/biopsy) procedures have been proposed to stratify patients according to different classes of GC risk. As a consequence, different patient-tailored GC secondary prevention strategies have been put forward. This review summarizes the histological features of H. pylori-related gastritis and the natural history of the disease. Histological and serological strategies to assess GC risk as well as the clinical management of atrophic gastritis patients are also discussed.

Helicobacter pylori-Induced Chronic Gastritis and Assessing Risks for Gastric Cancer

Chronic gastritis is an inflammation of the gastric mucosa and has multiple etiologies. Here we discuss the pathological alterations induced by Helicobacter pylori (HP) leading to chronic gastritis and the epigenetic bases underlying these changes. We review the histology of the normal gastric mucosa and overview the role of HP in the multistep cascade of GC. We attempt to define the role of the Operative Link for Gastritis Assessment (OLGA) staging system in assessing the risk of GC. The epigenetic bases of chronic gastritis, mainly DNA methylation, are presented through examples such as (i) the methylation of the promoter region of E-cadherin in HP-induced chronic gastritis and its reversion after HP eradication and (ii) the association of methylation of the promoter region of Reprimo, a p53-mediated cell cycle arrest gene, with aggressive HP strains in high risk areas for GC. In addition, we discuss the finding of RPRM as a circulating cell-free DNA, offering the opportunity for noninvasive risk assessment of GC. Finally, the integration of OLGA and tissue biomarkers, by systems pathology approach, suggests that severe atrophy has a greater risk for GC development if, in addition, overexpressed p73. This trial is registered with ClinicalTrials.gov NCT01774266.

Helicobacter pylori is a risk factor for colonic neoplasms

OBJECTIVES

It has been suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of adenomatous polyps and adenocarcinoma of the colon. Our aim was to study the association between H. pylori-positive gastritis and the occurrence of any colonic neoplasm.

METHODS

From a computerized database of surgical pathology reports, we selected 156,000 subjects who underwent colonoscopy and esophago-gastro-duodenoscopy with biopsy results from both procedures.

RESULTS

Compared with normal gastric mucosa, H. pylori gastritis occurred more frequently among patients with hyperplastic polyps (OR=1.24, 95% CI: 1.18-1.30), adenomatous polyps (1.52, 1.46-1.57), advanced adenomas (1.80, 1.69-1.92), villous adenomas or adenomas with high-grade dysplasia (1.97, 1.82-2.14), and adenocarcinomas (2.35, 1.98-2.80). Similarly, the strength of the association between H. pylori-positive gastritis and colonic neoplasm increased with size and number of the adenomas. The association between H. pylori gastritis and the occurrence of colonic neoplasm was similar for different locations of the large bowel. Other gastric conditions etiologically associated with H. pylori, such as intestinal metaplasia, adenoma, lymphoma, and adenocarcinoma, were also significantly associated with an increased risk of colonic neoplasm.

CONCLUSIONS

Various forms of gastritis related to H. pylori infection confer an increased risk for colonic neoplasm. In the past, when H. pylori infection was more prevalent, its attributable risk to the occurrence of colorectal neoplasm may have been quite substantial.

Early HER2 dysregulation in gastric and oesophageal carcinogenesis

AIMS

To explore human epidermal growth factor receptor 2 (HER2) status in the histological phenotypes [metaplasia, intraepithelial neoplasia (IEN, i.e. dysplasia), and adenocarcinoma] involved in the morphogenesis of both intestinal-type gastric cancer (GC) and Barrett's adenocarcinoma (BAc).

METHODS AND RESULTS

A consecutive series of 275 samples of stomach and oesophagus tissue (representing the whole spectrum of the phenotypic changes involved in gastric and Barrett's carcinogenesis) was studied. HER2 status was assessed by applying two immunohistochemistry (IHC) protocols, using the antibodies 4B5 and CB11. Dual-colour silver chromogenic in-situ hybridization (SISH) was also performed on the same tissue samples. In both oesophageal and gastric samples, the rate of HER2 overexpression rose significantly from low-grade to high-grade IEN to adenocarcinoma (P < 0.001), with the two IHC protocols showing consistent staining (consistency 95%; k = 0.78; P < 0.001). Intratumour heterogeneity was documented in both GC and BAc (using both IHC protocols). The rate of HER2 amplification (using SISH) increased significantly along with IEN dedifferentiation (P < 0.001). Neither native nor metaplastic mucosa samples (obtained from either stomach or oesophagus) ever showed HER2 amplification. There was excellent agreement between HER2 amplification and protein overexpression (both IHC protocols: SISH/4B5--consistency 97.8%, k = 0.89, P < 0.001; SISH/CB11-consistency 97.8%, k = 0.91, P < 0.001).

CONCLUSIONS

There is early involvement of HER2 dysregulation (amplification and protein overexpression) in both gastric (intestinal-type) and Barrett's oncogenesis.

Autoimmune gastritis: histology phenotype and OLGA staging

BACKGROUND

Among Western populations, the declining incidence of Helicobacter pylori infection coincides with a growing clinical impact of autoimmune gastritis.

AIMS

To describe the histological phenotype of autoimmune gastritis, also to test the prognostic impact of OLGA staging in the autoimmune setting.

METHODS

A single-institutional series (spanning the years 2003-2011) of 562 consecutive patients (M:F ratio: 1:3.7; mean age = 57.6 ± 14.4 years) with serologically confirmed autoimmune gastritis underwent histology review and OLGA staging.

RESULTS

Helicobacter pylori infection was ascertained histologically in 44/562 cases (7.8%). Forty six biopsy sets (8.2%) featured OLGA stages III-IV; they included all four cases of incidental epithelial neoplasia (three intraepithelial and one invasive; three of these four cases had concomitant H. pylori infection). There were 230 (40.9%) and 139 (24.7%) cases, respectively, of linear and micro-nodular enterochromaffin-like cell hyperplasia; 19 (3.4%) type I carcinoids were detected. The series included 116 patients who underwent repeated endoscopy/biopsy sampling (mean time elapsing between the two procedures = 54 months; range 24-108). Paired histology showed a significant (P = 0.009) trend towards a stage progression [the stage increased in 25/116 cases (22%); it remained unchanged in 87/116 cases (75%)].

CONCLUSIONS

In autoimmune gastritis, the cancer risk is restricted to high-risk gastritis stages (III-IV), and is associated mainly with concomitant H. pylori infection. OLGA staging consistently depicts the time-dependent organic progression of the autoimmune disease and provides key information for secondary gastric cancer prevention strategies.

First-degree relatives of patients with early-onset gastric carcinoma show even at young ages a high prevalence of advanced OLGA/OLGIM stages and dysplasia

BACKGROUND

First-degree relatives (FDRs) of early-onset gastric carcinoma (EOGC) patients are at increased risk of cancer development. OLGA/OLGIM (Operative Link on Gastritis/Intestinal Metaplasia Assessment) classifications have been proposed for the identification of individuals at high risk of gastric cancer development.

AIM

To estimate the prevalence and severity of premalignant conditions and lesions in FDRs of EOGC patients.

METHODS

A case-control study was conducted encompassing 103 FDRs of EOGC patients (cases) and 101 age- and gender-matched controls, all submitted to upper GI endoscopy and OLGA and OLGIM used for staging as well as modified versions with exclusion of the biopsies from incisura angularis in the analysis.

RESULTS

Helicobacter pylori infection was present in 82% of cases (P = 0.001). Atrophy was present in 70% of cases (OLGA stages I-IV). High-risk stages (III-IV) were identified only in cases (19%) (P < 0.001). Dysplasia was diagnosed only in cases (n = 7, P = 0.007). The application of OLGIM, modified OLGA and modified OLGIM classifications led to downgrade of stages in comparison with the original OLGA classification (27%, 15% and 30% respectively). In all classification systems, dysplastic lesions clustered (86%) in high-risk stages.

CONCLUSIONS

FDRs of EOGC patients have, even at young ages, a high prevalence of H. pylori infection, high-risk OLGA and OLGIM stages and dysplasia. These patients should undergo accurate endoscopic observation with at least four biopsies in antrum and corpus to allow adequate staging and follow-up of premalignant conditions and lesions scored in high-risk stages, in accordance with international guidelines recently proposed.

Lesions indefinite for intraepithelial neoplasia and OLGA staging for gastric atrophy

Gastric intraepithelial neoplasia (IEN; formerly dysplasia) is an advanced precancerous lesion. Lesions indefinite for IEN mimic the IEN phenotype but lack some morphologic attributes of IEN. Indefinite for IEN lesions may arise in native foveolae (atypical foveolar hyperproliferation [aFH]) or intestinalized glands (hyperproliferative intestinal metaplasia [HIM]). The clinicopathologic outcome of such lesions is debated. We retrospectively studied the clinicopathologic behavior of 129 consecutive indefinite for IEN lesions (HIM, 98; aFH, 31; median follow-up, 31 months) and correlated outcome with the extent and topography of mucosal atrophy (assessed by OLGA staging) at the initial endoscopy/biopsy. At enrollment, aFH never coexisted with severe/extensive atrophy (all cases were in low-risk OLGA stages [0-II]), whereas HIM was associated with low- and high-risk OLGA stages (0-II, 73; III-IV, 25). At follow-up, IEN was never documented among cases enrolled as aFH, while follow-up endoscopy/biopsy documented 6 neoplastic intraepithelial lesions among 98 cases of HIM (6%, all had high-risk OLGA stages at initial biopsy). OLGA staging can stratify indefinite for IEN lesions into different risk classes, potentially contributing to decisions for a patient-specific follow-up strategy.

Operative link for gastritis assessment vs operative link on intestinal metaplasia assessment

AIM: To compare the reliability of gastritis staging systems in ranking gastritis-associated cancer risk in a large series of consecutive patients.

METHODS: Gastric mucosal atrophy is the precancerous condition in which intestinal-type gastric cancer (GC) most frequently develops. The operative link for gastritis assessment (OLGA) staging system ranks the GC risk according to both the topography and the severity of gastric atrophy (as assessed histologically on the basis of the Sydney protocol for gastric mucosal biopsy). Both cross-sectional and long-term follow-up trials have consistently associated OLGA stages III-IV with a higher risk of GC. A recently-proposed modification of the OLGA staging system (OLGIM) basically incorporates the OLGA frame, but replaces the atrophy score with an assessment of intestinal metaplasia (IM) alone. A series of 4552 consecutive biopsy sets (2007-2009) was retrieved and reassessed according to both the OLGA and the OLGIM staging systems. A set of at least 5 biopsy samples was available for all the cases considered.

RESULTS: In 4460 of 4552 cases (98.0%), both the high-risk stages (III + IV) and the low-risk stages (0 +I + II) were assessed applying the OLGA and OLGIM criteria. Among the 243 OLGA high-risk stages, 14 (5.8%) were down-staged to a low risk using OLGIM. The 67 (1.5%) incidentally-found neoplastic lesions (intraepithelial or invasive) were consistently associated with high-risk stages, as assessed by both OLGA and OLGIM (P < 0.001 for both). Two of 34 intestinal-type GCs coexisting with a high-risk OLGA stage (stage III) were associated with a low-risk OLGIM stage (stage II).

CONCLUSION: Gastritis staging systems (both OLGA and OLGIM) convey prognostically important information on the gastritis-associated cancer risk. Because of its clinical impact, the stage of gastritis should be included as a conclusive message in the gastritis histology report. Since it focuses on IM alone, OLGIM staging is less sensitive than OLGA staging in the identification of patients at high risk of gastric cancer.