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

The association between acid-suppressive agent use and the risk of cancer: a systematic review and meta-analysis

BACKGROUND

Acid-suppressive agents (ASAs) may be associated with cancer; previous studies reported that the risk of cancer with acid suppressants has differed depending on the site of cancer. Here, we conducted a systematic review and meta-analysis of the association between ASA use and the type of cancer risk.

METHODS

MEDLINE, EMBASE, and Cochrane library databases were searched for publications up to the end of September 2019 for MeSH terms and text words related to cancer and ASAs. Studies on the association between ASAs and cancer risk, which included a control group and reported the relative risk of cancer, were included. The inverse-variance random effect model was used to estimate the pooled relative risk (RR) and 95% confidence interval (CI), and subgroup analysis for type of acid suppressants, drug uptake duration, and cumulative doses was performed. Heterogeneity was assessed using the I² test and Q statistic.

RESULTS

Thirty-nine cohort and case-control studies were included. ASA use was found to be significantly associated with a 46% higher risk of gastric cancer (RR, 1.46; 95% CI, 1.18-1.80) and a 53% higher risk of liver cancer (RR, 1.53; 95% CI, 1.31-1.78) compared with nonuse; however, there was no significant association for esophageal, colorectal, pancreatic, lung, breast, prostate, and kidney cancer; melanoma; and lymphoma.

CONCLUSIONS

ASAs were significantly associated with an increased risk of gastric and liver cancer; therefore, special attention of ASA use considering the potential risk of gastric and liver cancer is needed.

Systematic review: the effects of long-term proton pump inhibitor use on serum gastrin levels and gastric histology

BACKGROUND

Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy.

AIM

To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology.

METHODS

A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology.

RESULTS

A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8-52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47-4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25-20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found.

CONCLUSIONS

Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found.

Acid suppressive drugs and gastric cancer: A meta-analysis of observational studies

AIM: To evaluate the association between acid suppressive drug use and the development of gastric cancer.

METHODS: A systematic search of relevant studies that were published through June 2012 was conducted using the MEDLINE (PubMed), EMBASE, and Cochrane Library databases. The search included observational studies on the use of histamine 2-receptor antagonists (H₂RAs) or proton pump inhibitors and the associated risk of gastric cancer, which was measured using the adjusted odds ratio (OR) or the relative risk and 95%CI. An independent extraction was performed by two of the authors, and a consensus was reached.

RESULTS: Of 4595 screened articles, 11 observational studies (n = 94558) with 5980 gastric cancer patients were included in the final analyses. When all the studies were pooled, acid suppressive drug use was associated with an increased risk of gastric cancer risk (adjusted OR = 1.42; 95%CI: 1.29-1.56, I² = 48.9%, P = 0.034). The overall risk of gastric cancer increased among H₂RA users (adjusted OR = 1.40; 95%CI: 1.24-1.59, I² = 59.5%, P = 0.008) and PPI users (adjusted OR = 1.39; 95%CI: 1.19-1.64, I² = 0.0%, P = 0.377).

CONCLUSION: Acid suppressive drugs are associated with an increased risk of gastric cancer. Further studies are needed to test the effect of acid suppressive drugs on gastric cancer.

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.

Gastric atrophy, diagnosing and staging

H pylori is now accepted as the cause of gastritis and gastritis-associated diseases, such as duodenal ulcer, gastric ulcer, gastric carcinoma, and gastric MALT lymphoma. The natural history of H pylori gastritis includes inflammation progressing from the antrum into the adjacent corpus resulting in an atrophic front of advancing injury leading to a reduction in acid secretion and eventual loss of parietal cells and development of atrophy. Sub-typing intestinal metaplasia has no clinical value to the patient, the pathologist, or the endoscopist. The pattern, extent, and severity of atrophy, with or without intestinal metaplasia, is a far more important predictor than is intestinal metaplasia subtype. The challenge remains to identify a reliable marker that relates to pre-malignant potential.

Review article: helicobacter pylori and molecular events in precancerous gastric lesions

Gastric cancer can be divided into intestinal type and diffuse type that differ substantially in epidemiology and pathogenesis. The most important aetiological factor associated both with intestinal and diffuse gastric cancer, is Helicobacter pylori. Exposure of gastric epithelial cells to H. pylori results in an inflammatory reaction with the production of reactive oxygen species and nitric oxide that, in turn, deaminates DNA causing mutations. The complex interplay between H. pylori strain, inflammation and host characteristics may directly promote diffuse type gastric cancer or induce a cascade of morphological events, i.e. atrophy, intestinal metaplasia and dysplasia, finally leading to intestinal type gastric cancer. Two mechanisms, genetic and epigenetic have been held to play a role in the molecular alterations underlying gastric carcinogenesis. The former, comprising changes in the DNA sequence, is irreversible; the latter, involving DNA methylation, is potentially reversible by eliminating the triggering agents. If H. pylori is eradicated before development of stable mutations, the risk of gastric cancer will likely be prevented. Thus, eradication of H. pylori might immediately reduce the risk of diffuse type gastric cancer, whereas prevention of intestinal type gastric cancer may be less effective if patients are treated later in the evolution of the carcinogenic process.

Genotyping of Helicobacter pylori in paraffin-embedded gastric biopsy specimens: relation to histological parameters and effects on therapy

OBJECTIVES

Colonization with Helicobacterpylori can lead to GI disease. Bacterial genotypes and host factors, such as acid production, can influence the progress of disease. We investigated H. pylori genotypes and histological parameters in the same paraffin-embedded gastric biopsy specimens.

METHODS

Paraffin-embedded antrum and corpus biopsy samples from 75 gastroesophageal reflux disease patients were histologically examined and tested for H. pylori vacA (s and m regions), cagA, and iceA genotypes. Patients were investigated at baseline (58 H. pylori positive and 17 H. pylori negative) and after treatment with omeprazole with or without additional antibiotic therapy.

RESULTS

Genotyping at baseline was complete in 52 (90%) of the 58 H. pylori positive patients. Multiple genotypes were detected in eight (14%) of these. Genotypes were highly consistent between antrum and corpus biopsy specimens at baseline and in follow-up samples. Genotypes from paraffin sections matched those from corresponding cultured strains in 10 selected cases. In the antrum, the degree of inflammation was associated with vacA s1 and cagA+ genotypes, and the degree of neutrophil activity was associated with the cagA+ genotype. In the corpus, the degree of inflammation was significantly associated with vacA s1, cagA+, and iceA1 genotypes and the degree of atrophy was associated with vacA s1, m1, and cagA+ genotypes, whereas the degree of neutrophil activity was associated with vacA s1 and cagA+ genotypes. vacA s2 and cagA-strains appeared more resistant to antibiotic therapy, irrespective of resistance to clarithromycin.

CONCLUSIONS

Our findings confirm the relevance of the H. pylori genotypes for the severity of gastric disease and the efficacy of antibiotic therapy.