Gastric intestinal metaplasia type III cases are classified as low-grade dysplasia on the basis of morphometry

Should Special Staining (AB/PAS) be Routinely Performed in Gastric Biopsies for the Detection of Intestinal Metaplasia?

Background. Gastric intestinal metaplasia increases the risk of gastric cancer by nine times. Although attempts are made to diagnose it using endoscopic methods, the final diagnosis is established by examining and reporting biopsy samples. Although there are studies in the literature that do not recommend routine special staining, many laboratories routinely perform alcian blue/periodic acid Schiffs (AB/PAS) staining, in addition to hematoxylin and eosin (H&E) staining. In this study, we examined the need for performing routine special staining. Methods. Seven hundred forty-one consecutive gastric biopsies obtained from the archive of our laboratory in 2019 were included in the study. One day after evaluating the cases using H&E, they were evaluated with AB/PAS without examining the H&E results. Result. All of the intestinal metaplasia lesions detected in H&E were observed with AB/PAS. However, we missed 14 (13.73%) of 102 intestinal metaplasia lesions with H&E that we detected using AB/PAS. We found the sensitivity and specificity of H&E in detecting intestinal metaplasia were 86.3% and 99.7%, respectively. When we retrospectively examined the 14 missed lesions in H&E staining, we could observe intestinal metaplasia in six biopsies, but it was not possible in eight (7.8%). Conclusion. Considering that gastric intestinal metaplasia is a precancerous lesion, we think that this ratio (13.73%) is high and that the number of malignancies can be reduced with a low-cost special stain. In this context, we advocate and recommend routinely performing inexpensive special staining such as AB/PAS to detect intestinal metaplasia in all gastric biopsies.

Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

From Helicobacter pylori infection to gastric cancer: Current evidence on the immune response

Gastric cancer (GC) is the result of a multifactorial process whose main components are infection by Helicobacter pylori (H. pylori), bacterial virulence factors, host immune response and environmental factors. The development of the neoplastic microenvironment also depends on genetic and epigenetic changes in oncogenes and tumor suppressor genes, which results in deregulation of cell signaling pathways and apoptosis process. This review summarizes the main aspects of the pathogenesis of GC and the immune response involved in chronic inflammation generated by H. pylori.

Histochemistry in the diagnosis of non-neoplastic gastrointestinal disorders

The alimentary tract serves as host to a large number of diseases. In the non-neoplastic group of disorders, conventional histochemistry continues to play an important diagnostic role. It is particularly important in recognizing specific infectious diseases, such as Helicobacter gastritis, Whipple disease, intestinal tuberculosis and other forms of mycobacteriosis, malakoplakia, intestinal spirochetosis, fungal enteritides, amebiasis, cryptosporidiosis, isosporiasis, and microsporidiosis. Those conditions and their histochemical properties are discussed in this review, along with the use of histochemistry in the characterization of structural gastrointestinal disorders. The latter include mucosal metaplasias, amyloidosis, glycogenic acanthosis of the esophagus, lymphocytic-collagenous colitis, gastric neuroendocrine hyperplasia, and pill gastritis.

Helicobacter pylori associated chronic gastritis, clinical syndromes, precancerous lesions, and pathogenesis of gastric cancer development

Helicobacter pylori (H. pylori) infection is well known to be associated with the development of precancerous lesions such as chronic atrophic gastritis (AG), or gastric intestinal metaplasia (GIM), and cancer. Various molecular alterations are identified not only in gastric cancer (GC) but also in precancerous lesions. H. pylori treatment seems to improve AG and GIM, but still remains controversial. In contrast, many studies, including meta-analysis, show that H. pylori eradication reduces GC. Molecular markers detected by genetic and epigenetic alterations related to carcinogenesis reverse following H. pylori eradication. This indicates that these changes may be an important factor in the identification of high risk patients for cancer development. Patients who underwent endoscopic treatment of GC are at high risk for development of metachronous GC. A randomized controlled trial from Japan concluded that prophylactic eradication of H. pylori after endoscopic resection should be used to prevent the development of metachronous GC, but recent retrospective studies did not show the tendency. Patients with precancerous lesions (molecular alterations) that do not reverse after H. pylori treatment, represent the "point of no return" and may be at high risk for the development of GC. Therefore, earlier H. pylori eradication should be considered for preventing GC development prior to the appearance of precancerous lesions.

Intestinal stem cell marker LGR5 expression during gastric carcinogenesis

AIM: To investigate the differential expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) in gastric cancer tissues and its significance related to tumor growth and spread.

METHODS: Formalin-fixed biopsy specimens of intestinal metaplasia (n = 90), dysplasia (n = 53), gastric adenocarcinoma (n = 180), metastases in lymph nodes and the liver (n = 15), and lesion-adjacent normal gastric mucosa (controls; n = 145) were obtained for analysis from the Peking University Cancer Hospital’s Department of Pathology and Gastrointestinal Surgery tissue archives (January 2003 to December 2011). The biopsied patients’ demographic and clinicopathologic data were retrieved from the hospital’s medical records database. Each specimen was subjected to histopathological typing to classify the tumor node metastasis (TNM) stage and to immunohistochemistry staining to detect the expression of the cancer stem cell marker LGR5. The intergroup differences in LGR5 expression were assessed by Spearman’s rank correlation analysis, and the relationship between LGR5 expression level and the patients’ clinicopathological characteristics was evaluated by the χ² test or Fisher’s exact test.

RESULTS: Significantly more gastric cancer tissues showed LGR5⁺ staining than normal control tissues (all P < 0.01), with immunoreactivity detected in 72.2% (65/90) and 50.9% (27/53) of intestinal metaplasia and dysplasia specimens, respectively, 52.8% (95/180) of gastric adenocarcinoma specimens, and 73.3%% (11/15) of metastasis specimens, but 26.9% (39/145) of lesion-adjacent normal gastric mucosa specimens. Comparison of the intensity of LGR5⁺ staining showed an increasing trend that generally followed increasing dedifferentiation and tumor spread (normal tissue < dysplasia, < gastric adenocarcinoma < metastasis; all P < 0.001), with the exception of expression level detected in intestinal metaplasia which was higher than that in normal gastric tissues (P < 0.001). Moreover, gastric cancer-associated enhanced expression of LGR5 was found to be significantly associated with age, tumor differentiation, Lauren type and TNM stage (I + II vs III + IV) (all P < 0.05), but not with sex, tumor site, location, size, histology, lymphovascular invasion, depth of invasion, lymph node metastasis or distant metastasis. Patients with LGR5⁺ gastric cancer specimens and without signs of metastasis from the original biopsy experienced more frequent rates of recurrence or metastasis during follow-up than patients with LGR5^- specimens (P < 0.05).

CONCLUSION: Enhanced LGR5 is related to progressive dedifferentiation and metastasis of gastric cancer, indicating the potential of this receptor as an early diagnostic and prognostic biomarker.

Utility of subtyping intestinal metaplasia as marker of gastric cancer risk. A review of the evidence

The identification and surveillance of patients with preneoplastic lesions at high risk of progressing to gastric cancer (GC) represents the most effective way of reducing the burden of GC. The incomplete type of intestinal metaplasia (IM) could be considered as the best candidate for surveillance. However, the usefulness of subtyping of IM has been considered by some authors as limited and inconsistent. A search was carried out to identify all cross-sectional (n=14) and follow-up (n=10) studies that assessed the risk of GC among subjects with different types of IM. Out of the 14 cross-sectional studies, 13 reported that the prevalence of incomplete IM was statistically significantly higher in GC than in other gastric lesions. Out of the ten follow-up studies, six found a statistically significant association between incomplete IM and subsequent GC risk. The relative risks of GC were from 4- to 11-fold higher for the presence of incomplete type in comparison to complete type or in comparison to the absence of incomplete type, among the studies that reported the magnitude of the risk. According to this comprehensive review, most of the scientific evidence supports the utility of subtyping IM as a predictor of GC risk. Recognizing its usefulness by gastroenterologists should encourage pathologists to subtype IM.

The gastric precancerous cascade

Invasive gastric carcinoma is preceded by a cascade of precancerous lesions. The first recognized histologic change is active chronic inflammation, which may persist as such: non-atrophic chronic gastritis (no gland loss), or advance to multifocal atrophic gastritis (MAG), the first real step in the precancerous cascade. The following steps are: intestinal metaplasia (first "complete" and then "incomplete"); dysplasia, first low grade and then high grade (equivalent to "carcinoma in situ"). The following step is invasive carcinoma, which is thought to be associated with degradation of the intercellular matrix.

Operative Link for Gastritis Assessment gastritis staging incorporates intestinal metaplasia subtyping

Both sulfomucin-type intestinal metaplasia (ie, types II and III intestinal metaplasia, colonic-type intestinal metaplasia) and gastritis in Operative Link for Gastritis Assessment stages III and IV are associated with an increased risk of intestinal-type gastric cancer. This study aimed to verify the hypothesis that gastritis in Operative Link for Gastritis Assessment stages III and IV (both consistently associated with an increased cancer risk) is associated per se with types II and III intestinal metaplasia. Two hundred consecutive cases of atrophic gastritis (Operative Link for Gastritis Assessment stages I, II, III, and IV) were considered (50 cases for each stage). All cases were stained with high iron diamine, and intestinal metaplasia was subtyped accordingly (type I [ie, small-intestinal type] and types II and III). Helicobacter pylori status was also considered, distinguishing H pylori-positive versus H pylori-negative versus H pylori-eradicated patients. A significant association was found between intestinal metaplasia subtype and the Operative Link for Gastritis Assessment stage of gastritis (the higher the stage, the more the colonic-type of intestinal metaplasia, and vice versa; Wilcoxon, P = .001). The strength of the association between Operative Link for Gastritis Assessment stages and the 3 intestinal metaplasia subtypes was confirmed by logistic regression analysis (P < .001; odds ratio, 4.84; 95% confidence interval, 2.97-7.88). Intestinal metaplasia subtyping also correlated with the patient's age (Kruskal-Wallis, P = .001) and H pylori status (Fisher exact, P < .001). Operative Link for Gastritis Assessment staging incorporates the prognostic message obtainable from histochemical gastric mucin subtyping.

The diagnostic accuracy of endoscopic biopsy for gastric dysplasia

Purpose

There is controversy over the treatment for low grade dysplasia, while resection is recommended for high grade dysplasia. But the concordance of the grade of dysplasia between pre- and post-resection is low because of sampling errors with endoscopic biopsy. We attempted to establish a clearer direction for the treatment of dysplasia by clarifying the discrepancy between the pre- and post-resection diagnoses.

Materials and Methods

We performed a retrospective review of 126 patients who had undergone resection with the diagnosis of dysplasia on biopsy at Bundang CHA Hospital from 1999 to 2009.

Results

Seventy patients were diagnosed with low grade dysplasia and 56 patients were diagnosed with high grade dysplasia. Among the 33 patients who received gastrectomy with lymph node dissection, 30 patients were revealed to have invasive cancers and 4 patients showed lymph node metastasis. Discordance between the diagnoses from biopsy and resection occurred in 55 patients (44%). There was no correlation on the comparative analysis between the size, location or gross type of lesion and the grade of dysplasia.

Conclusions

The rate of discordance between the diagnoses of endoscopic biopsy and the post resection pathologic report was as high as 44%. Endoscopic mucosal resection was not sufficient for some patients who were diagnosed with dysplasia on biopsy due to the presence of lymph node metastasis. It is necessary to be prudent when determining the follow-up and treatment based solely on the result of the biopsy.

Mucin phenotype of gastric cancer and clinicopathology of gastric-type differentiated adenocarcinoma

Differentiated adenocarcinoma of the stomach is classified into gastric or intestinal phenotypes based on mucus expression. Recent advances in mucin histochemistry and immunohistochemistry have highlighted the importance of such a distinction, and it is important clinically to distinguish between gastric- and intestinal-type differentiated adenocarcinoma. However, a clinical and pathological diagnosis of this type is often difficult in early gastric cancer because of histological similarities between a hyperplastic epithelium and low-grade atypia. Furthermore, determining tumor margins is often difficult, even with extensive preoperative examination. It is therefore critical to consider these diagnostic difficulties and different biological behaviors with high malignant potential when treating patients with gastric-type differentiated adenocarcinoma.

The impact of biopsy number and site on the accuracy of intestinal metaplasia detection in the stomach A morphometric study based on virtual biopsies

BACKGROUND

Intestinal metaplasia is a risk factor for gastric carcinoma. So far few studies have focused on the efficacy of endoscopic biopsies in detecting intestinal metaplasia in relation with the site and number of biopsies performed. The present study is aimed to assess the efficacy of single and multiple gastric biopsies in the detection and staging of intestinal metaplasia.

MATERIAL AND METHODS

The study was conducted on 455 gastrectomies. We defined the extent of intestinal metaplasia on surgical specimens sampled by the "Swiss roll" technique and assessed the efficiency of an increasing number of "virtual" biopsies performed on the same rolls in recognising the true extent of intestinal metaplasia in the antro-angular region.

RESULTS

Seventy-four out of 455 cases showed intestinal metaplasia in more than 5% of the antro-angular mucosa. The correlation between antro-angular intestinal metaplasia on rolls and on virtual biopsies was always highly significant, both when a single biopsy was considered and when groups of multiple biopsies (from 2 to 6 samples) were taken into account (p<or=0.0001 and rho ranging from 0.304 to 0.817). By increasing the number of biopsies (from 1 to 6) we observed an increase in the rate of correct estimations when 20% extent was used as a cut-off: the increase was statistically significant in both intestinal metaplasia >or=20% and intestinal metaplasia <20% groups (p<0.0001). The highest value of concordance between intestinal metaplasia extent in virtual biopsies and in rolls was recorded for a set of 4 antral+1 angular biopsies whereas a set of 2 antral+1 angular biopsies turned out to be the most effective in terms of number/efficacy.

CONCLUSIONS

A three biopsy set (2 antral+1 angular) allows correct detection of intestinal metaplasia extent in 90% of cases.

Phenotypic differences between esophageal and gastric intestinal metaplasia

Intestinal metaplasia is a cancer precursor in the esophagus and the stomach. Marked differences exist between the carcinogenic processes in the two locations in terms of natural history and clinical significance. We investigated biopsies from 52 patients with Barrett's esophagus and from 50 patients with gastric intestinal metaplasia in an attempt to throw light on their pathogenic processes. Morphologic characteristics, presence of Helicobacter pylori (H. pylori), and markers of differentiation, inflammation, and proliferation were evaluated by histochemical and immunohistochemical techniques. The area covered by incomplete type of intestinal metaplasia and the proportion of sulfomucins were significantly higher in the esophagus than in the stomach. Immunoreactivity with MUC1, MUC2, MUC5AC, Das-1, cytokeratins 7 and 20, inducible nitric oxide synthase and cyclooxygenase-2 antibodies was also significantly greater in Barrett's esophagus than in gastric intestinal metaplasia. In gastric intestinal metaplasia, the presence of MUC1, MUC5AC, Das-1 and cytokeratin 7 was restricted to areas with the incomplete type of metaplasia. Cell proliferation (Ki-67) was significantly higher in Barrett's esophagus than in gastric intestinal metaplasia. H. pylori was absent in all of the patients with Barrett's esophagus, while it was present in 70% of the patients with gastric intestinal metaplasia. Our observations made clear that Barrett's esophagus shares some phenotypic characteristics with gastric intestinal metaplasia, leading us to suggest that both could arise in response to injuries with eventual carcinogenic potential. However, the progression to more advanced lesions could be modulated by the nature of the carcinogenic insult.

Feasibility and cost-effectiveness of using magnification chromoendoscopy and pepsinogen serum levels for the follow-up of patients with atrophic chronic gastritis and intestinal metaplasia

BACKGROUND

The follow-up of patients with atrophic chronic gastritis or intestinal metaplasia may lead to early diagnosis of gastric cancer. However, to-date no cost-effective model has been proposed. Improved endoscopic examination using magnification chromoendoscopy together with non-invasive functional assessment with pepsinogen serum levels are accurate in the diagnosis of intestinal metaplasia (extension) and minute dysplastic lesions. The aim of this study was to assess the feasibility and cost-effectiveness of a follow-up model for patients with atrophic chronic gastritis and intestinal metaplasia based on gastric mucosal status using magnification chromoendoscopy and pepsinogen.

METHODS

A cohort of patients with lesions as severe as atrophic chronic gastritis were followed-up according to a standardized protocol using magnification chromoendoscopy with methylene blue and measurement of serum pepsinogen I and II levels. A single node decision tree and Markov chain modeling were used to define cost-effectiveness of this follow-up model versus its absence. Transition rates were considered time-independent and calculated using primary data following cohort data analysis. Costs, quality of life and survival were estimated based on published data and extensive sensitivity analysis was performed.

RESULTS

A total of 100 patients were successfully followed-up over 3 years. Seven cases of dysplasia were diagnosed during follow-up, all among patients with incomplete intestinal metaplasia at baseline, six of whom had extensive (pepsinogen I to II ratio <3) incomplete intestinal metaplasia. For those individuals with atrophic chronic gastritis or complete intestinal metaplasia, a yearly measurement of pepsinogen levels or an endoscopic examination on a 3-yearly basis would cost 455 euros per quality-adjusted life year (QALY) gain. Endoscopic examination and pepsinogen serum level measurement on a yearly basis would cost 1868 euros per QALY for patients with extensive intestinal metaplasia.

CONCLUSIONS

The follow-up of patients with atrophic chronic gastritis or intestinal metaplasia is both feasible and cost-effective if improved accurate endoscopic examination of gastric mucosa together with non-invasive assessment of gastric mucosal status are used to identify individuals at high-risk for development of gastric cancer.

Assessing risks for gastric cancer: new tools for pathologists

Although the Sydney Systems (original and updated) for the classification of gastritis have contributed substantially to the uniformity of the reporting of gastric conditions, they lack immediacy in conveying to the user information about gastric cancer risk. In this review, we summarize the current understanding of the gastric lesions associated with an increased risk for cancer, and present the rationale for a proposal for new ways of reporting gastritis. In addition to the traditional histopathological data gathered and evaluated according to the Sydney System rules, pathologists could add an assessment expressed as grading and staging of the gastric inflammatory and atrophic lesions and integrate these findings with pertinent laboratory information on pepsinogens and gastrin levels. Such an integrated report could facilitate clinicians' approach to the management of patients with gastric conditions.

Aneuploidies, deletion, and overexpression of TP53 gene in intestinal metaplasia of patients without gastric cancer

Gastric carcinogenesis is attributable to interacting environmental and genetic factors, through a sequence of events including intestinal metaplasia. Using a fluorescence in situ hybridization technique, we investigated the occurrence of aneuploidies of chromosomes 3, 7, 8, 9, and 17, TP53 gene deletion, and expression of p53 in 21 intestinal metaplasia (IM) samples from cancer-free patients and in 20 gastric adenocarcinoma samples. Aneuploidies were found in 71% (15/21) of the IM samples. Trisomy of chromosomes 7 and 9 occurred mainly in complete-type IM; in the incomplete type, trisomy of chromosomes 7 and 8 were more commonly found. The TP53 gene deletion was observed in 60% (3/5) of the IM cases, and immunohistochemistry revealed p53 overexpression in 12% (2/17) of the analyzed IM cases. All gastric adenocarcinoma cases presented higher frequencies of trisomy or tetrasomy of chromosomes 3, 7, 8, 9, and 17. The TP53 deletion was found in all three of the gastric adenocarcinoma analyzed for it, and immunohistochemistry detected overexpression of protein p53 in 80% (12/15) of the analyzed cases. Our study revealed for the first time the presence of aneuploidies of chromosomes 7, 8, 9, and 17 and of TP53 gene deletion and overexpression in IM samples from cancer-free patients. These results suggest that IM and gastric adenocarcinoma may share the same genetic alterations.

Oxidative damage of the gastric mucosa in Helicobacter pylori positive chronic atrophic and nonatrophic gastritis, before and after eradication

BACKGROUND

Helicobacter pylori is the main cause of gastritis and a primary carcinogen. The aim of this study was to assess oxidative damage in mucosal compartments of gastric mucosa in H. pylori positive and negative atrophic and nonatrophic gastritis.

MATERIALS AND METHODS

Five groups of 10 patients each were identified according to H. pylori positive or negative chronic atrophic (Hp-CAG and CAG, respectively) and nonatrophic gastritis (Hp-CG and CG, respectively), and H. pylori negative normal mucosa (controls). Oxidative damage was evaluated by nitrotyrosine immunohistochemistry in the whole mucosa and in each compartment at baseline and at 2 and 12 months after eradication. Types of intestinal metaplasia were classified by histochemistry.

RESULTS

Total nitrotyrosine levels appeared significantly higher in H. pylori positive than in negative patients, and in Hp-CAG than in Hp-CG (p <.001); no differences were found between H. pylori negative gastritis and normal mucosa. Nitrotyrosine were found in foveolae and intestinal metaplasia only in Hp-CAG. At 12 months after H. pylori eradication, total nitrotyrosine levels showed a trend toward a decrease in Hp-CG and decreased significantly in Hp-CAG (p =.002), disappearing from the foveolae (p =.002), but remaining unchanged in intestinal metaplasia. Type I and II of intestinal metaplasia were present with the same prevalence in Hp-CAG and CAG, and did not change after H. pylori eradication.

CONCLUSIONS

Oxidative damage of the gastric mucosa increases from Hp-CG to Hp-CAG, involving the foveolae and intestinal metaplasia. H. pylori eradication induces a complete healing of foveolae but not of intestinal metaplasia, reducing the overall oxidative damage in the mucosa.

Columnar-lined esophagus. Definitions

Recognition of a columnar-lined esophagus requires precise criteria by which to delimit the esophagus and the stomach. Endoscopically recognizable landmarks such as the squamocolumnar junction (SCJ or Z-line) can be used to identify structures at the gastroesophageal junction. Once the SCJ is located proximal to the gastroesophageal junction, a columnar-lined segment of esophagus is visible. If biopsy specimens from the columnar-lined segment show specialized intestinal metaplasia, then the patient has Barrett's esophagus (BE), and the extent of the columnar lining determines if it is short- or long-segment BE.

Atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach: a reality or merely an hypothesis?

The results of recent investigations have suggested that the old hypothesis of an atrophy-metaplasia-dysplasia-carcinoma sequence in the stomach needs to be qualified. The most common cause of intestinal metaplasia is Helicobacter pylori gastritis. The consequence of this intestinal metaplasia is focal atrophy. Helicobacter pylori infection may also trigger an autoimmune gastritis of the corpus mucosa, with atrophy and intestinal metaplasia. Most intestinal metaplasias are only 'paracancerous' but not 'precancerous' lesions. Diffuse gastric carcinomas, such as the signet ring cell carcinoma, arise independently of intestinal metaplasia. Histogenetically, numerous carcinomas of the stomach are primarily of the gastric type, and may secondarily change into the intestinal type.High-grade intra-epithelial neoplasias (dysplasias) detected during the biopsy-based diagnostic work-up appear to be a marker for carcinoma and must, therefore, be removed endoscopically. The detection of intestinal metaplasia in routinely obtained biopsy material is subject to sampling error and is, therefore, not a suitable marker for an increased risk of a gastric carcinoma developing. As an alternative, the concept of gastritis of the carcinoma phenotype, which is more frequently found in early gastric carcinomas and in the relatives of gastric carcinoma patients, has been developed. In this concept, the diffuse parameters of grade and activity of the gastritis in the antrum and corpus, which are independent of sampling error, are subjected to a comparative analysis. A risk gastritis of the carcinoma phenotype is diagnosed when the grade and activity of the gastritis in the corpus are at least equally as pronounced as in the antrum. Currently, this concept is being tested in a prospective ongoing study. Future studies must show whether, and if so which, immunohistochemical or molecular-genetically detectable changes can be applied as risk markers in the diagnostic work-up. Helicobacter pylori eradication probably does not lead to complete regression of the intestinal metaplasia and ensuing focal atrophy. However, eradication of H. pylori does lead to the normalization of changes that can lead to mutations of the stem cells of the gastric mucosa (free radicals, nitric oxide, cell proliferation and vitamin C secretion).

Long-term lansoprazole treatment for gastro-oesophageal reflux disease: clinical efficacy and influence on gastric mucosa

BACKGROUND

Long-term acid suppression is believed to accelerate atrophic gastritis in Helicobacter pylori-positive patients. The influence of long-term therapy with lansoprazole has not been examined.

AIM

To study the clinical and endoscopic efficacy and histological evolution of gastric mucosa during 5 years of maintenance treatment with lansoprazole, 30 mg.

METHODS

Seventy-eight patients with endoscopically proven oesophagitis were followed for 5 years. Biopsies taken at the start of the study, during follow-up and after 5 years were available for 73 patients.

RESULTS

The total endoscopic relapse rate was 14.1%. At the start of the study, 34 patients were Helicobacter pylori negative and 39 were Helicobacter pylori positive (two atrophy, 25 antral gastritis, 12 pangastritis). At 5 years, no histological changes had occurred in Helicobacter pylori-negative patients. In the Helicobacter pylori-positive group, 20 patients developed pangastritis, six had normal histology and one had antral gastritis. Ten of the 12 patients with pangastritis had reduced antral activity. There was no increase in intestinal metaplasia, but there was a tendency towards regression of atrophy in the antrum and towards increased atrophy in the body of the stomach.

CONCLUSIONS

Maintenance treatment with lansoprazole, 30 mg, is efficacious. The development of glandular atrophy and intestinal metaplasia was not accelerated in Helicobacter pylori-positive patients. Helicobacter pylori eradication must be considered only because of the higher cancer risk associated with chronic Helicobacter pylori-related gastritis.

Review article: pre-neoplastic states of the gastric mucosa--a practical approach for the perplexed clinician

The sequence leading to gastric cancer can be schematically reduced to Helicobacter pylori infection-chronic gastritis-atrophy-intestinal metaplasia-dysplasia-neoplasia. Although clinicians have not yet developed a uniform approach to the treatment of gastritis (when should H. pylori infection be treated?), the entity itself is not the subject of controversy. All other lesions are still the focus of debate. There are no guidelines for the management of patients with intestinal metaplasia; pathologists are still searching for universal diagnostic criteria for atrophic gastritis; dysplasia and early neoplasia have elicited scientific diatribes between Japanese and Western pathologists. Amidst such controversies and in the absence of guidelines to regulate the management of gastric lesions, the responsibility to provide sensible clinical advice is often bestowed upon pathologists. This review discusses whether pathologists have access to sufficient evidence to provide the requested advice, and whether a consensus on the management of gastric "pre-neoplastic" states is within reach. We conclude that, although many sensible and useful definitions, criteria and classifications are being generated, the final decision on how to manage the individual patient with gastric lesions will continue to be based on the communication between pathologist and clinician.

Barrett's oesophagus: diagnosis and management

Gastro-oesophageal reflux disease and its sequela, Barrett's oesophagus, are the major recognized risk factors for oesophageal adenocarcinoma, a tumour whose frequency has increased dramatically in Western countries over the past few decades. Barrett's oesophagus develops through the process of metaplasia in which one adult cell type replaces another. The metaplastic, intestinal-type cells of Barrett's oesophagus are predisposed to develop genetic changes that eventuate in cancer. This report reviews the recent controversy regarding diagnostic criteria for Barrett's oesophagus, and provides practical guidelines for identifying the condition. The risks and benefits of the proposed medical, surgical and endoscopic therapies for Barrett's oesophagus are discussed in detail, and the approach to management recently endorsed by the American College of Gastroenterology is summarized.

Gastric pathology associated with Helicobacter pylori

A bacterium is associated with a specific gastritis. Neutrophils infiltrate the necks of the glands, just deep to the infected foveolae. This infiltration rarely, if ever, occurs without H. pylori infection. Foveolar epithelial damage is common, with loss of cell structure. Electron microscopy suggests that the bacteria cause this damage as they attach to the superficial cell membrane. These features, defined by Whitehead et al as active changes, appear specific for H. pylori infection. The neutrophils and specific epithelial changes disappear within days of starting treatment for Helicobacter. They rapidly recur if the treatment is unsuccessful. Without treatment, the changes remain for decades and are severe in 10% to 20% of cases. Other changes occur in the mucosa. Reduced mucus secretion occurs in damaged or proliferating epithelium. This reduced secretion occurs near healing ulcers or with other types of inflammation but is often severe when Helicobacter is present. It returns to normal within weeks of treating the infection. The bacteria adhering to the cell membrane may cause this change directly. Lymphoid infiltration occurs with any type of chronic inflammation or immune reaction. The infiltration is not specific for Helicobacter, and it reduces slowly in months or years after eradication of H. pylori. Peptic ulceration, particularly duodenal ulceration, although not specific, is particularly common with H. pylori infection. The long-term inflammation probably causes other gastric pathology. Atrophy is common. Epithelial metaplasia occurs in about 20% of patients, usually mild. Other features, such as scarring, epithelial dysplasia, and in situ malignant change, are less common. They show little improvement after eradicating H. pylori. The part played by the bacteria in their cause remains uncertain. Pathologists see a long-standing chronic gastritis clearly related to a bacterium. The inflammation often is severe and commonly damages the mucosa, with ulceration, atrophy, metaplasia, and occasional premalignant changes. Physicians would treat inflammation of this degree in most other parts of the body. This disease is usually symptomless. There is some controversy, but eradicating Helicobacter often fails to improve nonulcer dyspepsia. This failure results in a continuing argument over whether or not to treat the infection. Meanwhile the pathology continues. A temporary solution to the problem is suggested: Patients infected with Helicobacter can give informed consent. Patients can be told about the infection, the pathology, the poor relationship to symptoms, and side effects of therapy, and they can decide.

Topographic patterns of intestinal metaplasia and gastric cancer

OBJECTIVE

The role of intestinal metaplasia in gastric oncogenesis has been demonstrated by both cross-sectional and longitudinal studies. This study was designed to determine whether, in a population at high risk for gastric cancer, different topographical patterns and phenotypes of intestinal metaplasia were associated with different degrees of cancer risk.

METHODS

A total of 68 Colombian patients with gastric cancer and 67 controls with nonulcer dyspepsia were studied by an extensive biopsy protocol. Intestinal metaplasia was assessed semiquantitatively by histology and was characterized histochemically. In both patients and controls, the Spearman's correlation test was applied to the test if the gastric distribution of metaplastic lesions resulted in specific topographical patterns associated with different risks for cancer.

RESULTS

Four topographical patterns of intestinalization emerged: 1) "Focal," in 14 cancer patients and 16 controls; 2) "Antrum-predominant," in seven cancer patients and six controls; 3) "Magenstrasse" (involving the lesser curvature from cardia to pylorus) in 25 cancer patients and four controls. This pattern was associated with higher cancer risk (OR = 5.7; 95% CI: 1.3-26) than were the two less extensive patterns; and 4) "Diffuse," involving essentially the entire gastric mucosa with the exception of the fundus, was unique to 13 cancer patients. The OR for cancer was 12.2; 95% CI: 2.0-72.9. Incomplete-type metaplasia significantly correlated with the extent of total metaplasia and was also associated with greater cancer risk.

CONCLUSIONS

In a population with high risk for gastric cancer, the extension of intestinal metaplasia correlates with the extent of its "incomplete" phenotype and is significantly associated with increased cancer risk. Both the extent and location of intestinal metaplasia along the lesser curvature (from the cardia to the prepyloric zones) identify patients with the highest cancer risk.

Evolution of precancerous lesions in a rural Chinese population at high risk of gastric cancer

The pathogenesis of gastric cancer (GC), particularly of the intestinal type, is thought to involve a multistep and multifactorial process. Our objective was to determine the rates of transition from early to advanced gastric lesions in a population in Linqu County, China, where the GC rates are among the highest in the world. An endoscopic screening survey was launched in 1989-1990 among 3,399 residents aged 34-64 years with precancerous lesions diagnosed from biopsies taken from 7 standard locations in the stomach and from any suspicious sites. The cohort was subsequently followed, with endoscopic and histopathologic examinations conducted in 1994. Logistic regression analysis was used to estimate odds ratios (ORs) of progression to advanced lesions of various levels of severity as a function of age, sex and baseline pathology. The rates of progression were higher among older subjects, among men and among subjects with more extensive gastric lesions. 34 incident GCs were identified during the follow-up period. The ORs of GC, adjusted for age and sex, varied from 17.1, for those with baseline diagnoses of superficial intestinal metaplasia (IM), to 29.3, for those with deep IM or mild dysplasia (DYS) or IM with glandular atrophy and neck hyperplasia, to 104.2, for those with moderate or severe DYS, as compared with subjects with superficial gastritis (SG) or chronic atrophic gastritis (CAG) at baseline. Our prospective study of a high-risk population revealed sharp increases in the risk of GC and advanced precursor lesions according to the severity of lesions diagnosed at the start of follow-up. Int. J. Cancer, 83:615-619, 1999. Published 1999 Wiley-Liss, Inc.

Well-differentiated adenocarcinoma mimicking complete-type intestinal metaplasia in the stomach

We describe extremely well-differentiated intestinal-type adenocarcinomas of the stomach which mimic complete-type intestinal metaplasia. It is often difficult to discriminate such neoplastic lesions from inflamed or regenerative changes of intestinal metaplasia histologically. The aim of this study was to elucidate the clinicopathologic features of this unique carcinoma. Eight cases of gastric carcinoma of this type that were invasive beyond the muscularis mucosae were selected for mucin histochemical and immunohistochemical analyses. The carcinomas showed the following features: (1) predominant cells that had differentiated to mature neoplastic cells, with features of small intestinal absorptive cells (complete-type intestinal metaplastic cells), which have sialomucin, MUC2-positive cells, and brush border features detected by CD10 (56C6) staining; (2) neoplastic tubules in the mucosa showing branching, tortuous, anastomosing, and plexiform structures, which were more pathognomonic than the cytological features; (3) lesions distributed predominantly in the middle third of the stomach and surrounded by the fundic mucosa; and (4) zonal distribution of Ki-67-positive proliferative cells like those of intestinal metaplasia in the lower third to half of the cancerous tubules in the mucosa. The lesions consisted mainly of illusory carcinoma; however, there were foci of pathognomonic elements in some areas of the tumors. Several biopsy samplings of the lesion would ensure the histopathologic diagnosis. This unique lesion forms a subgroup of intestinal-type carcinomas of the stomach and is suggested to have a close link with complete-type intestinal metaplasia, previously ignored as a precancerous lesion.

The role of gastric carditis in metaplasia and neoplasia at the gastroesophageal junction

Adenocarcinomas at the gastroesophageal junction appear to arise from foci of intestinal metaplasia that develop either in the distal esophagus or the proximal stomach (the gastric cardia). Metaplasia is usually a consequence of chronic inflammation, and it is logical to assume that intestinal metaplasia at the gastroesophageal junction develops as a result of chronic inflammation in the epithelia that normally line the junction region. Intestinal metaplasia in the esophagus is known to be a sequela of chronic inflammation in squamous epithelium caused by gastroesophageal reflux disease, whereas intestinal metaplasia in the distal stomach is often a consequence of chronic gastritis caused by Helicobacter pylori infection. For the gastric cardia, the contributions of gastroesophageal reflux disease, H. pylori infection, and other factors to inflammation, metaplasia, and neoplasia are not clear. If physicians are to develop meaningful preventive strategies and specific therapies for tumors of the proximal stomach, a clear understanding of pathogenesis is important. Recent studies on pathogenetic factors for inflammation in cardiac epithelium (gastric carditis) have yielded contradictory results, perhaps because of fundamental differences in the techniques used by different investigators for identifying and sampling the gastric cardia. This report explores the roots of the controversy regarding the role of gastric carditis in the development of metaplasia and neoplasia at the gastroesophageal junction and suggests practical guidelines for biopsy protocols to be used in future studies that will be necessary to resolve these disputes.

Intestinal metaplasia with adherent Helicobacter pylori: a hybrid epithelium with both gastric and intestinal features

Helicobacter pylori seem to avoid areas of intestinal metaplasia in the gastric mucosa, but attachment of these bacteria to epithelium with the appearance of incomplete intestinal metaplasia has been documented. To characterize the nature of the epithelium to which H pylori was attached, we carried out an immunohistochemical study using monoclonal antibodies against gastric surface mucous cell mucins (M1), blood group-related carbohydrates antigens (Le(a), sialyl Le(a), Le(b), type 1H, and type 2H) and sialyl Tn antigen. The results of this study suggest that these areas of H pylori attachment represent a hybrid epithelium whose cells share characteristics of both gastric surface mucous cells and intestinal metaplastic cells. Whether all areas of incomplete intestinal metaplasia represent an intermediate stage between the normal gastric epithelium and the fully developed complete type of metaplasia remains to be determined.

Nuclear morphometry as a predictor of disease outcome in gastric cancer

Nuclear morphometric features including nuclear area (NA), nuclear perimeter (PE), their variation (SDNA, SDPE), and mean largest and smallest nuclear diameters (Dmax, Dmin) were examined in 116 patients with stage I-II gastric adenocarcinoma. Morphometric measurements were compared with tumour differentiation, depth of invasion (pT), lymph node status (pN), and Lauren classification. All morphonuclear features were significantly larger in the intestinal type than in the diffuse type of cancer. None of the morphometric variables was related to TNM status or tumour size. Nuclear area and perimeter and their variation were closely related to survival in univariate analysis, patients with small and regular nuclei surviving longer. In the multivariate analysis, pT, pN, perineural invasion, and the standard deviation of nuclear perimeter (SDPE) were independent predictors of survival. Nuclear morphometry is a quantitative, objective, and highly reproducible method of revealing malignant features in several neoplasms. The results of the present study suggest that nuclear morphometric data may help in defining prognosis in gastric cancer.

Classification and grading of gastritis. The updated Sydney System. International Workshop on the Histopathology of Gastritis, Houston 1994

The Sydney System for the classification of gastritis emphasized the importance of combining topographical, morphological, and etiological information into a schema that would help to generate reproducible and clinically useful diagnoses. To reappraise the Sydney System 4 years after its introduction, a group of gastrointestinal pathologists from various parts of the world met in Houston, Texas, in September 1994. The aims of the workshop were (a) to establish an agreed terminology of gastritis; (b) to identify, define, and attempt to resolve some of the problems associated with the Sydney System. This article introduces the Sydney System as it was revised at the Houston Gastritis Workshop and represents the consensus of the participants. Overall, the principles and grading of the Sydney System were only slightly modified, the grading being aided by the provision of a visual analogue scale. The terminology of the final classification has been improved to emphasize the distinction between the atrophic and nonatrophic stomach; the names used for each entity were selected because they are generally acceptable to both pathologists and gastroenterologists. In addition to the main categories and atrophic and nonatrophic gastritis, the special or distinctive forms are described and their respective diagnostic criteria are provided. The article includes practical guidelines for optimal biopsy sampling of the stomach, for the use of the visual analogue scales for grading the histopathologic features, and for the formulation of a comprehensive standardized diagnosis. A glossary of gastritis-related terms as used in this article is provided.

Immunohistochemical evaluation of keratin 20 expression in intestinal metaplasia types I to III

AIMS

To investigate differences in expression of keratin 20, a cytoskeletal protein in gastrointestinal epithelial cells, in completely differentiated intestinal metaplasia (type I) and incomplete metaplasia (types II and III).

METHODS

Gastric biopsy specimens from 66 patients with intestinal metaplasia were analysed immunohistochemically. Expression of keratin 20 was quantified as the percentage of immunoreactive cells on the tips, the upper, and deep foveolae.

RESULTS

In all specimens keratin 20 was found on the tips and in the upper foveolae of intestinal metaplasia. Keratin 20 was not observed in the deep foveolae. No differences were seen between the antrum and the body. Expression patterns were comparable between types I and III. In type II, however, lower immunoreactivity was found. Both the differences between types I and II as well as between types II and III were significant (p < 0.05).

CONCLUSIONS

Keratin 20 is expressed in metaplastic mucosa as a result of intestinal differentiation. Positive staining found exclusively in juxtaluminal cells occurs only in mature cells containing keratin 20. Lowered immunoreactivity in type II compared with types I and III indicates the different nature of type II intestinal metaplasia. Further studies are needed to shed light on the basic fundamental mechanism responsible for this.

Recognizing atrophy: another step toward a classification of gastritis

The Sydney System is a novel classification of gastritis that attempts to incorporate etiologic, topographic, and morphologic criteria into a clinically relevant scheme. In September of 1994, a group of 20 gastric pathologists from various parts of the world gathered in Houston, Texas, U.S.A., to reappraise the Sydney System 4 years after its introduction and to attempt to reach a broad consensus on gastritis. One of the most controversial issues at the Houston Workshop was the concept of atrophy. Several factors converge to foment confusion and disagreement. "Normal" is imprecisely defined; the loss of glands occurs with distinct patterns and has different functional significance in antrum and corpus; inflammatory infiltrate and lymphoid follicles in the lamina propria may alter the architecture of the gastric mucosa, particularly in the antrum, making loss especially arduous to discern from mere displacement; the relationship between atrophy and intestinal metaplasia remains incompletely understood; and finally, and perhaps most important, the topographic patterns of distribution and the genesis and evolution of atrophic gastritis have been among the most divisive predicaments in the tumultuous arena of gastritis. This article explores some of the difficulties surrounding the concept of atrophy, summarizes the resolutions made at the Houston Workshop, and presents a novel approach to the histopathologic evaluation of atrophic gastritis.

Pancreatic metaplasia of the human gastric mucosa is associated with high expression of transforming growth factor alpha but not of epidermal growth factor

Pancreatic acinar metaplasia of the gastric mucosa is a newly recognized entity. Its physiological relevance and association with other pathological conditions in the stomach remain to be elucidated. We studied by immunohistochemistry the expression of growth markers in the gastric mucosa in biopsies from 15 patients with recognized pancreatic metaplasia. Pancreatic metaplasia (both acinar and dispersed forms) was found in routine paraffin sections and confirmed by strong lipase immunoreactivity. In parallel paraffin sections we performed immunostaining for epidermal growth factor (EGF), transforming growth factor-alpha (TGF alpha) and epidermal growth factor receptor (EGFr) using a biotin streptavidin method. Strong expression of TGF alpha but only weak expression of EGF was noted within metaplastic mucosa. EGFr was strongly expressed, not only in areas of pancreatic metaplasia but also in the surrounding gastric mucosa.

Cell proliferation patterns and p53 expression in gastric dysplasia

Gastric dysplasia (high-grade, HGD, and low-grade, LGD) and normal mucosa were tested for anti-p53, anti-Ki-67 and anti-PCNA monoclonal antibodies on paraffin sections, and for relative AgNOR area and number on semithin Epon-Araldite sections. The proliferative compartment in normal mucosa was restricted to the middle layer corresponding to the neck-isthmus region. In LGD and HGD there was an expansion of this compartment to the lower and upper layers of mucosa, and in HGD in particular to the upper layer. p53 was always negative in LGD as well as in normal mucosa, while it was positive in 34 out of 51 cases of HGD. The most discriminant variables between LGD and HGD were relative AgNOR area and the percentages of MIB-1, p53 and PCNA. In p53-positive HGD the highest percentages of PCNA and MIB-1 were in the middle and upper layers (PCNA) or the upper layer (MIB-1), while in p53-negative HGD cases cell proliferation was maximal in the middle layer, although also present in the upper layer. The majority of cases of LGD did not demonstrate cell proliferation in the upper layer, but 5 cases behaved similarly to the p53-negative HGD cases. No significant correlations were found among percentages of MIB-1 and of PCNA and relative AgNOR area and number.