Rapid quantitative assessment of gastric corpus atrophy in tissue sections

An intelligent decision support system for quantitative assessment of gastric atrophy

Aims

To build an automated decision support system to assist pathologists in grading gastric atrophy according to the updated Sydney system.

Methods

A database of 143 biopsies was used to train and examine the proposed system. A panel of three experienced pathologists reached a consensus regarding the grading of the studied biopsies using the visual scale of the updated Sydney system. Digital imaging techniques were utilised to extract a set of discriminating morphological features that describe each atrophy grade sufficiently and uniquely. A probabilistic neural networks structure was used to build a grading system. To evaluate the performance of the proposed system, 66% of the biopsies (94 biopsy images) were used for training purposes and 34% (49 biopsy images) were used for testing and validation purposes.

Results

During the training phase, a 98.9% precision was achieved, whereas during testing, a precision of 95.9% was achieved. The overall precision achieved was 97.9%.

Conclusions

A fully automated decision support system to grade gastric atrophy according to the updated Sydney system is proposed. The system utilises advanced image processing techniques and probabilistic neural networks in conducting the assessment. The proposed system eliminates inter- and intra-observer variations with high reproducibility.

The staging of gastritis with the OLGA system by using intestinal metaplasia as an accurate alternative for atrophic gastritis

BACKGROUND

The OLGA (operative link on gastritis assessment) staging system is based on severity of atrophic gastritis (AG). AG remains a difficult histopathologic diagnosis with low interobserver agreement, whereas intestinal metaplasia (IM) is associated with high interobserver agreement.

OBJECTIVE

The aim of this study was to evaluate whether a staging system based on IM is preferable to estimate gastric cancer risk.

DESIGN AND SETTING

Prospective multicenter study.

PATIENTS

A total of 125 patients previously diagnosed with gastric IM or dysplasia.

INTERVENTIONS

Surveillance endoscopy with extensive biopsy sampling.

MAIN OUTCOME MEASUREMENTS

Three pathologists graded biopsy specimens according to the Sydney classification. Interobserver agreement was analyzed by kappa statistics. In the OLGA, AG was replaced by IM, creating the OLGIM.

RESULTS

Interobserver agreement was fair for dysplasia (kappa = 0.4), substantial for AG (kappa = 0.6), almost perfect for IM (kappa = 0.9), and improved for all stages of OLGIM compared with OLGA. Overall, 84 (67%) and 79 (63%) patients were classified as stage I-IV according to OLGA and OLGIM, respectively. Of the dysplasia patients, 5 (71%) and 6 (86%) clustered in stage III-IV of OLGA and OLGIM, respectively.

LIMITATION

Prospective studies should confirm the correlation between gastric cancer risk and OLGIM stages.

CONCLUSION

Replacement of AG by IM in the staging of gastritis considerably increases interobserver agreement. The correlation with the severity of gastritis remains at least as strong. Therefore, the OLGIM may be preferred over the OLGA for the prediction of gastric cancer risk in patients with premalignant lesions.

Interobserver variations in histopathological assessment of gastric pathology

AIM

Considering the fact that histology and its grading systems are accepted gold standards in diagnosis of diverse clinical disorders, assessing the accuracy and reliability of this method of diagnosis is of utmost importance. Thus, this study was performed to measure the agreement values between four independent histopathology readings for identical indices under one scoring guideline using three different approaches.

METHODS

Four independent pathologists participated in this study and were blinded to the clinical diagnosis of patients. Various histological features were examined on gastric tissue specimens according to the updated Sydney system.

RESULTS

Statistical analysis revealed that our null hypothesis about the existing agreement between different histopathological observations is rejected for chronic gastritis, the presence of inflammatory activity, atrophy and Helicobacter pylori, whereas there were significant inter-observation agreements in regard to the presence of lymphoid follicles, intestinal metaplasia and dysplasia. Pairwise analysis showed that different grading scales resulted in different kappa values ranging from poor to excellent agreements. The best kappa values were observed for the evaluation of dysplasia between two independent pathologists.

CONCLUSIONS

This assessment has demonstrated that standardisation of less quantitative grading scales resulting in consistent readings is essential for affirmative clinical diagnosis and devising effective treatment strategies.

Serum biomarker tests are useful in delineating between patients with gastric atrophy and normal, healthy stomach

AIM

To study the value of serum biomarker tests to differentiate between patients with healthy or diseased stomach mucosa: i.e. those with Helicobacter pylori (H pylori) gastritis or atrophic gastritis, who have a high risk of gastric cancer or peptic ulcer diseases.

METHODS

Among 162 Japanese outpatients, pepsinogen I (Pg I) and II (Pg II) were measured using a conventional Japanese technique, and the European GastroPanel examination (Pg I and Pg II, gastrin-17 and H pylori antibodies). Gastroscopy with gastric biopsies was performed to classify the patients into those with healthy stomach mucosa, H pylori non-atrophic gastritis or atrophic gastritis.

RESULTS

Pg I and Pg II assays with the GastroPanel and the Japanese method showed a highly significant correlation. For methodological reasons, however, serum Pg I, but not Pg II, was twice as high with the GastroPanel test as with the Japanese test. The biomarker assays revealed that 5% of subjects had advanced atrophic corpus gastritis which was also verified by endoscopic biopsies. GastroPanel examination revealed an additional seven patients who had either advanced atrophic gastritis limited to the antrum or antrum-predominant H pylori gastritis. When compared to the endoscopic biopsy findings, the GastroPanel examination classified the patients into groups with "healthy" or "diseased" stomach mucosa with 94% accuracy, 95% sensitivity and 93% specificity.

CONCLUSION

Serum biomarker tests can be used to differentiate between subjects with healthy and diseased gastric mucosa with high accuracy.

Noninvasive imaging of macrophages in rheumatoid synovitis using 11C-(R)-PK11195 and positron emission tomography

OBJECTIVE

Noninvasive imaging by positron emission tomography (PET) of macrophages in inflamed joints of patients with rheumatoid arthritis (RA) may allow early detection of disease activity. We undertook this study to investigate whether rheumatoid synovitis can be visualized by PET using the tracer 11C-(R)-PK11195, which binds to peripheral benzodiazepine receptors (PBRs) on macrophages.

METHODS

Knee joints of 11 RA patients with active arthritis of at least 1 knee joint were imaged with 11C-(R)-PK11195 PET. Tissue uptake of 11C-(R)-PK11195 was quantified. PET was followed by arthroscopy of the most inflamed knee joint of each RA patient. Synovial tissue samples were subjected to immunohistochemical staining.

RESULTS

11C-(R)-PK11195 uptake on the PET scans was significantly higher in severely inflamed joints than in joints with moderate or mild signs of inflammation. In addition, tracer uptake in contralateral uninflamed knee joints of RA patients was significantly higher than in uninflamed joints of control patients without inflammatory joint disease, suggesting the presence of subclinical disease activity. PET tracer uptake in joints correlated significantly with PBR staining in the sublining of synovial tissue. PBR staining correlated significantly with CD68 staining of macrophages.

CONCLUSION

11C-(R)-PK11195 PET imaging allows noninvasive in vivo imaging of macrophages in rheumatoid synovitis and possibly even in subclinical synovitis. Noninvasive visualization of macrophages may be useful both for detecting early synovitis and for monitoring synovitis activity during treatment.

Loss of 1p36, gain of 8q24, and loss of 9q34 are associated with stroma percentage of colorectal cancer

Interactions between neoplastic cells and neighboring stromal cells affect tumor morphology and behavior. The present study aimed to identify specific chromosomal aberrations that influence tumor-stroma interactions in colorectal cancer (CRC). Chromosome copy number changes of 23 carcinomas were analyzed by comparative genomic hybridization (array-CGH). Stroma percentage was determined by quantitative measurements of hematoxylin-eosin stained sections. Loss of 1p36 was associated with a decrease, and loss of 9q34 with an increase in CRC stroma percentage. Moreover, gain of 8q24 was associated with increased stroma percentage in CRCs with 20q gain, a major event in colon adenoma-to-carcinoma progression. These data indicate that different cancer genomes have different effects on tumor-stroma interactions, and suggest that determination of specific chromosomal aberrations in CRCs may be used as clinical parameter to predict tumor behavior.

Proton pump inhibitors and Helicobacter pylori gastritis: friends or foes?

H. pylori gastritis and gastric acid closely interact. In H. pylori-positive patients, profound acid suppressive therapy induces a corpus-predominant pangastritis, which is associated with accelerated corpus gland loss and development of atrophic gastritis. Both corpus-predominant and atrophic gastritis have been associated with an increased risk of development of gastric cancer. H. pylori eradication leads to resolution of gastritis and may induce partial regression of pre-existent gland loss. H. pylori eradication does not aggravate GERD nor does it impair the efficacy of proton pump inhibitor maintenance therapy for this condition. This is the background of the advise within the European guidelines for the management of H. pylori infection to offer an H. pylori test and treat policy to patients who require proton pump inhibitor maintenance therapy for GERD. As such a policy fully reverses H. pylori pangastritis even in patients who have been treated for years with proton pump inhibitors, there is no need to eradicate H. pylori before the start of proton pump inhibitors. In fact, the somewhat slower initial response of H. pylori-negative GERD patients to proton pump inhibitor therapy and the fact that many GERD patients will only require short-term therapy suggests to first start the proton pump inhibitor, and only test and treat when maintenance therapy needs to be prescribed. Such considerations prevent the persistent presence of active corpus-predominant gastritis in proton pump inhibitor-treated reflux patients without impairing the clinical efficacy of treatment.

The detection, surveillance and treatment of premalignant gastric lesions related to Helicobacter pylori infection

Gastric cancer is an important worldwide health problem and causes considerable morbidity and mortality. It represents the second leading cause of cancer-related death worldwide. A cascade of recognizable precursor lesions precedes most distal gastric carcinomas. In this multistep model of gastric carcinogenesis, Helicobacter pylori causes chronic active inflammation of the gastric mucosa, which slowly progresses through the premalignant stages of atrophic gastritis, intestinal metaplasia and dysplasia to gastric carcinoma. Detection and treatment of premalignant lesions may thus provide a basis for gastric cancer prevention. However, at present, premalignant changes of the gastric mucosa are frequently disregarded in clinical practice or result in widely varying follow-up frequency or treatment. This review provides an overview of current knowledge on detection, surveillance and treatment of patients with premalignant gastric lesions, and identifies the uncertainties that require further research.

Quantitative assessment of gastric antrum atrophy shows restitution to normal histology after Helicobacter pylori eradication

BACKGROUND/AIMS

Grading gastric mucosal atrophy in antrum biopsy specimens remains a controversial subject because of limitations in interobserver agreement. We previously described a reliable, quantitative method for grading atrophy of the corpus mucosa with excellent reproducibility and good correlation with the Sydney scores. The aims of the present study were to evaluate the applicability of this method for the grading of antral atrophy and to study the effect of Helicobacter pylori eradication on the antral mucosa.

METHODS

Antrum biopsy specimens were collected from 71 gastroesophageal reflux disease patients at baseline and after 3 and 12 months. After the first endoscopy, all subjects were treated with omeprazole 40 mg daily for 12 months. After randomization, 27 of the 48 H. pylori-positive patients additionally received eradication therapy. In 182 hematoxylin-eosin-stained specimens, which were of sufficient quality, the proportions (volume percentages) of glands (VPGL), stroma (VPS), infiltrate (VPI), and intestinal metaplasia in the glandular zone of the antrum mucosa were measured using a point-counting method. In these specimens, mucosal atrophy was assessed by two experienced gastrointestinal tract pathologists (E.B. and J.L.) according to the updated Sydney classification as either nonatrophic mucosa (n = 47) or as mild (n = 29), moderate (n = 50), or marked (n = 56) atrophy. In addition, a group of 23 cases with difficult-to-classify grades of atrophy were included.

RESULTS

The mean VPGL decreased with increasing Sydney grades of atrophy (p < 0.001), while the mean VPS and VPI increased (both p < 0.001). After H. pylori eradication, even the cases with the lowest VPGL regressed to normal levels.

CONCLUSIONS

Overall, a low VPGL correlates with increasing grades of antrum mucosal atrophy. The present data indicate that gastric mucosal atrophy is reversible, since almost all cases showed regression of VPGL after H. pylori eradication. The cases with difficult-to-classify grades of atrophy showed significantly lower VPGLs and higher VPIs than the reference cases.

Helicobacter pylori eradication and gastric preneoplastic conditions: a randomized, double-blind, placebo-controlled trial

Helicobacter pylori causes gastric adenocarcinoma; whether treatment of H. pylori infection prevents this cancer remains unknown. In a randomized, double-blind, placebo-controlled trial of H. pylori eradication, we determined whether treatment for H. pylori decreases gastric cancer risk, using preneoplastic conditions as surrogate markers. A total of 248 healthy volunteers (age >40 years) randomly received H. pylori treatment (omeprazole, amoxicillin, clarythromycin; n = 122) or matched placebo (n = 126) for 1 week. Endoscopy was performed at baseline and at 6 weeks and 1 year. Seven biopsies from each endoscopy were reviewed by two pathologists using the revised Sydney classification. Outcome measures were both a consensus "worst biopsy" diagnosis and a weighted index score that incorporated degrees of severity of preneoplasia from all biopsies. We compared change in these outcomes over time between the two treatment groups. H. pylori cure rates for compliant subjects in the treatment arm were 79.2% and 75.7% at 6 weeks and 1 year, respectively. No statistically significant change in the worst biopsy diagnosis was observed from 6 weeks to 1 year between placebo and treated subjects (for improvement/worsening, placebo, 19.4%/10.5%; treatment, 22.5%/8.3%; P = 0.74). Change in index score was favorably greater in treatment compared with placebo subjects (intention-to-treat analysis, P = 0.03); this finding was particularly evident in the antrum. H. pylori eradication gave more favorable gastric histopathologies over 1 year than no treatment. Such incomplete regression suggests but does not prove that eradication of H. pylori decreases cancer risk.

Interobserver variation in histopathological assessment of Helicobacter pylori gastritis

AIM

Because the presence or absence of H pylori infection has important implications for therapeutic decisions based on histological assessment, the reproducibility of Sydney system is important. The study was designed to test the reproducibility of features of Helicobacter pylori gastritis, using the updated Sydney classification.

METHODS

Gastric biopsies of 40 randomly selected cases of H pylori gastritis were scored semiquantitatively by three pathologists. Variables analysed included chronic inflammation, inflammatory activity, atrophy, intestinal metaplasia, H pylori, surface epithelial damage. Kappa values below 0.5 represented poor, those between 0.5 and 0.75 good and values over 0.75 excellent interobserver agreement.

RESULTS

The best interobserver agreement (kappa=0.62) was present for intestinal metaplasia. The agreement was the poorest for evaluating atrophy (kappa=0.31).

CONCLUSION

Although the results of this study were in accordance with some previous studies, an excellent agreement could not be reached for any features of H pylori gastritis. This low degree of concordance is assumed to be due to the personal evaluation differences in grading the features, the lack of standardized diagnostic criteria, and the ignorance to reach a consensus about the methods to be used in grading the features of H pylori gastritis before initiating the study.

Morphometric evaluation of gastric antral atrophy: improvement after cure of Helicobacter pylori infection

OBJECTIVE

Our purpose was to find out if morphometric techniques can document long term changes in gastric antral atrophy after curing Helicobacter pylori infection with or without dietary supplementation with antioxidant micronutrients.

METHODS

Study subjects were 132 adult volunteers from a Colombian region with high gastric cancer rates. Participants were randomly assigned to ascorbic acid, beta-carotene, and anti-H. pylori treatment, following a factorial design. Gastric biopsies were obtained at baseline and after 72 months of intervention. Atrophy was evaluated by a standard visual analog scale and by morphometry.

RESULTS

Statistically significant changes in antral atrophy were detected with morphometric techniques after intervention in subjects who received anti-H. pylori treatment. A nonsignificant trend was also observed with visual scores. This effect was greater among those who were free of infection at the end of the trial. After accounting for the effect of anti-H. pylori treatment, no significant effect was noted for dietary supplementation with ascorbic acid and/or beta-carotene.

CONCLUSIONS

We conclude that gastric atrophy improves significantly after long term control of H. pylori infection. This effect can be demonstrated both by conventional histological grading and by morphometry.

The dynamics of gastritis

The dynamics of gastritis remain a topic of intense investigation. The results of these investigations have increased our knowledge concerning the development of preneoplastic lesions and cancer of the stomach and given us insight with regard to the interactions among bacterial colonization, chronic inflammation, and carcinogenesis in other organs. The past year has presented us with further data showing that the progression of chronic gastritis to gland loss and gastric cancer is related to the severity of inflammation, which is influenced by the characteristics of the bacterial strain, host genetics, and hypochlorhydria. In contrast, Helicobacter pylori eradication leads to a rapid disappearance of neutrophils in the gastric mucosa. Chronic inflammation with mononuclear cells also improves upon eradication, but at a much slower rate, usually not leading to normalization within the first year after therapy. Whether H. pylori eradication can thus prevent new development of atrophy and metaplasia as well, or lead to regression of pre-existing lesions, has been the topic of many studies by now. Unfortunately, most of these studies have suffered from their case design, limited sample size, and short follow-up. Therefore, the conflict in outcome of these case studies comes as no surprise. The few prospective, randomized, controlled studies, however, strongly confirm that H. pylori eradication leads to healing of gastritis, which can at least halt further development of atrophy and metaplasia. Whether these lesions can truly regress remains to be proven.

Quantitative assessment of gastric corpus atrophy in subjects using omeprazole: a randomized follow-up study

OBJECTIVES

Atrophy of the gastric mucosa most frequently results from chronic Helicobacter pylori infection and is a risk factor for the development of gastric cancer. Profound acid suppression has been suggested to accelerate the onset of gastric mucosal atrophy. The aim of the present study was to evaluate the effects of H. pylori eradication and acid inhibition by omeprazole on gastric atrophy by means of quantitative analysis of tissue morphology.

METHODS

Corpus biopsy specimens were obtained during endoscopy in 71 gastroesophageal reflux disease (GERD) patients at baseline and after 3 and 12 months. A total of 48 subjects were H. pylori positive and 23 were H. pylori negative. All subjects received omeprazole 40 mg once daily after the first endoscopy for 12 months. After randomization, 27 of the 48 H. pylori-positive patients also received eradication therapy. In hematoxylin and eosin-stained slides the volume percentages of glands (VPGL), volume percentages of stroma (VPS), and volume percentages of infiltrate (VPI) were measured in the glandular zone of the mucosa. The results were evaluated by computerized morphometric analysis.

RESULTS

In the eradication group, the mean VPGL increased from 63.0% to 67.7% and 71.5% after 3 and 12 months (p < 0.001), respectively. The mean VPS and VPI decreased from 33.1% and 4.0% to 29.3% and 3.0% and to 26.4% and 2.1% (p < 0.001 and p = 0.04), respectively. Patients with the lowest VPGL at baseline showed the largest increases of VPGL after eradication treatment as compared to patients with high a VPGL at baseline. In the H. pylori-persistent group the VPI showed a significant increase (p = 0.01), and in the H. pylori-negative group VPGL increased significantly from 71.9% to 75.2% (p = 0.03) after 12 months.

CONCLUSIONS

Eradication of H. pylori leads to restitution of the volume percentage of glandular epithelium to normal levels, even during treatment with proton pump inhibitors. Whether this effect can also be seen in patients with marked atrophy needs further investigation.