Risk factors associated with gastric cancer in patients with a duodenal ulcer

Metachronous gastric neoplasm beyond 5 years after endoscopic resection for early gastric cancer

BACKGROUND AND AIMS

The natural course of early gastric cancer (EGC) following endoscopic submucosal dissection (ESD) remains unclear. This study aimed to clarify the long-term clinical outcomes and risk factors of metachronous gastric neoplasm (MGN) 5 years after ESD for EGC.

METHODS

We performed a retrospective analysis of patients who underwent ESD for EGC from July 2005 to October 2015 in Seoul National University Hospital. Long-term clinical outcomes and risk factors of MGN after 5 years post-ESD were evaluated.

RESULTS

Among the 2059 patients who underwent ESD for EGC, 1102 were followed up for > 5 years. MGN developed in 132 patients 5 years after ESD. During the median follow-up period of 85 months, the cumulative incidences of MGN and metachronous gastric cancer were 11.7, 16.9, and 27.0 and 7.6, 10.8, and 18.7% after 5, 7, and 10 years, respectively. In multivariable analysis, male sex (odds ratio 1.770; P = 0.042), severe intestinal metaplasia (odds ratio 1.255; P = 0.000), tumor-positive lateral margin (odds ratio 2.711; P = 0.008), < 5 mm lateral safety margin (odds ratio 1.568; P = 0.050), and synchronous adenoma (odds ratio 2.612; P = 0.001) were positive predictive factors, and successful eradication of Helicobacter pylori (odds ratio 0.514; P = 0.024) was a negative predictive factor for MGN after 5 years post-ESD.

CONCLUSION

The cumulative MGN incidence was high even 5 years post-ESD for EGC. Meticulous long-term endoscopic follow-up is mandatory, especially in male patients with underlying intestinal metaplasia, tumor-positive lateral margins, lateral safety margins of < 5 mm, and synchronous adenomas.

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

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

Update on the Diagnosis and Management of Gastric Intestinal Metaplasia in the USA

Gastric intestinal metaplasia (GIM) is a premalignant condition that can lead to intestinal-type gastric adenocarcinoma. It is characterized by a change in the gastric mucosa to a small-intestinal phenotype. Infection with Helicobacter pylori is the most common factor associated with GIM. Although GIM is typically a histologic diagnosis, various techniques have been developed to enable the endoscopic identification of GIM. There are presently no widely accepted guidelines on screening and surveillance strategies in patients with GIM in the USA. The aim of this review is to provide an update regarding the problem, diagnosis, and management of GIM in the USA.

Osteopontin polymorphism increases gastric precancerous intestinal metaplasia susceptibility in Helicobacter pylori infected male

AIM

Whether genetic polymorphisms of osteopontin (OPN) coding gene, SPP1, determine the risk of gastric precancerous intestinal metaplasia (IM) in Helicobacter pylori infected patients.

PATIENTS & METHODS

Helicobacter pylori infected patients (100 with and 210 without IM) were recruited to evaluate the associations of SPP1 promoter polymorphisms with gastric IM and adjusted for age, sex and smoking. Gastric OPN expression and inflammation were evaluated by immunohistochemistry, and haemotoxylin and eosin stain.

RESULTS

Only in males, but not females, carriage of both GG genotype at rs11730059 and C-G-C haplotype at rs6833161-rs2853744-rs11730582 significantly increased the IM risk (OR: 4.92; 95% CI: 1.65-14.65; p = 0.004). Nearly 87.5% of males with IM carried risky genotype or haplotype. Carriers of the risky genotype or haplotype also had increased gastric OPN expression (p = 0.038) and inflammation (p = 0.007).

CONCLUSION

SPP1 polymorphisms predispose to IM development in H. pylori infected males.

Helicobacter pylori Infection and Risk of Gastric Cancer in Korea: A Quantitative Systematic Review

Objectives:

In the context of the global decrease in mortality due to gastric cancer, previous studies have reported that the effect of chronic Helicobacter pylori (H. pylori) infection on the incidence of gastric cancer varies among regions. This systematic review was conducted to investigate H. pylori as a risk factor for gastric cancer in Korea, where the incidence of gastric cancer is among the highest in the world.

Methods:

A search strategy was established to identify articles published in Korean as well as in English. Ultimately, we included observational studies conducted among Korean patients that designed with an age-matched and sex-matched control group that reported the odds ratio associated with H. pylori. Gastric cancer cases were subdivided into overall (OGC), cardia (CGC), non-cardia (NGC), early (EGC), advanced, intestinal (IGC), and diffuse forms of gastric cancer. Summary odds ratios (SORs) with 95% confidence intervals (CIs) were calculated in the meta-analysis using a random-effect model.

Results:

Eleven case-control studies were ultimately selected. H. pylori was associated with an SOR of 1.81 (95% CI, 1.29 to 2.54) for OGC. Additionally, statistically significant risks were observed for CGC, NGC, EGC, and IGC.

Conclusions:

Chronic H. pylori infection was found to raise the risk of gastric cancer among Koreans, with the highest risk observed for CGC and EGC (SOR=2.88 for both). Follow-up clinical epidemiologic studies are needed to assess the effects of current treatments aimed at eradicating H. pylori infections.

β-Defensins in the Fight against Helicobacter pylori

Antimicrobial peptides (AMPs) play a pivotal role in the innate immune responses to Helicobacter pylori (Hp) in humans. β-Defensins, a class of cationic arginine-rich AMPs, are small peptides secreted by immune cells and epithelial cells that exert antimicrobial activity against a broad spectrum of microorganisms, including Gram-positive and Gram-negative bacteria and fungi. During Hp infections, AMP expression is able to eradicate the bacteria, thereby preventing Hp infections in gastrointestinal tract. It is likely that gastric β-defensins expression is increased during Hp infection. The aim of this review is to focus on increased knowledge of the role of β-defensins in response to Hp infection. We also briefly discuss the potential use of AMPs, either alone or in combination with conventional antibiotics, for the treatment of Hp infection.

Gastric intestinal metaplasia is associated with gastric dysplasia but is inversely correlated with esophageal dysplasia

AIM

To determine which clinical factors might be associated with gastric intestinal metaplasia (IM) in a North American population.

METHODS

Pathology and endoscopy databases at an academic medical center were reviewed to identify patients with and without gastric IM on biopsies for a retrospective cohort study. Patient demographics, insurance status, and other clinical factors were reviewed.

RESULTS

Four hundred and sixty-eight patients with gastric IM (mean age: 61.0 years ± 14.4 years, 55.5% female) and 171 without gastric IM (mean age: 48.8 years ± 20.8 years, 55.0% female) were compared. The endoscopic appearance of atrophic gastritis correlated with finding gastric IM on histopathology (OR = 2.05, P = 0.051). Gastric IM was associated with histologic findings of chronic gastritis (OR = 2.56, P < 0.001), gastric ulcer (OR = 6.97, P = 0.015), gastric dysplasia (OR = 6.11, P = 0.038), and gastric cancer (OR = 6.53, P = 0.027). Histologic findings of Barrett’s esophagus (OR = 0.28, P = 0.003) and esophageal dysplasia (OR = 0.11, P = 0.014) were inversely associated with gastric IM. Tobacco use (OR = 1.73, P = 0.005) was associated with gastric IM.

CONCLUSION

Patients who smoke or have the endoscopic finding of atrophic gastritis are more likely to have gastric IM and should have screening gastric biopsies during esophagogastroduodenoscopy (EGD). Patients with gastric IM are at increased risk for having gastric dysplasia and cancer, and surveillance EGD with gastric biopsies in these patients might be reasonable.

Gastric cancer related genes

Gastric cancer is one of the most common malignant tumors. In addition to environmental, socioeconomic, and dietary factors, hereditary factors also play an important role in the development of gastric cancer. Although some driver genes have been identified in gastric cancer, the molecular compositions of gastric cancer have not been fully understood. Genome-wide association studies, copy number variations and next-generation sequencing provide systematic methods to identify all genetic alterations in the cancer genome, especially in the field of mutation detection. Here we make a brief review of the current status of research on gastric cancer genetics.

Potential role of aquaporin 3 in gastric intestinal metaplasia

Gastric intestinal metaplasia (GIM) is a pre-cancerous condition and a pivotal step in the formation of gastric cancer (GC). Aquaporin 3 (AQP3) has been found to be expressed in goblet cells rather than mucus-secreting glands. To investigate the characteristics of GIM in non-cancerous tissues adjacent to GC, as well as the expression and role of AQP3 in GIM tissues, 16 patients diagnosed with gastric adenocarcinoma of intestinal type located in the lesser curve of the antrum were consecutively enrolled in this study. A new pathological technology called "gastric mucosal sausage roll" was introduced. GIM was determined according to the updated Sydney system, and AQP3 expression in goblet cells was determined by immunohistochemistry. GIM was found in all stomach specimens, and its incidence increased with progression to GC (P < 0.001). GIM prevalence displayed remarkable association with the distance to GC in the anterior gastric wall tissues (P = 0.016) and tissues toward the cardia (P = 0.014), such that GIM was more common in the areas closer to GC (P < 0.001). AQP3 was found to be expressed in 67.71% of parts with GIM, and AQP3 immunoreactivity was identified more frequently in severe GIM areas (P < 0.001). In short, the incidence and severity of GIM correlated with the distance from GC, and AQP3 was differentially expressed in goblet cells, with most AQP3-positive goblet cells presenting in severe GIM. Together, this study suggests that AQP3 may play an important role in gastric carcinogenesis from GIM.

History of Helicobacter pylori, duodenal ulcer, gastric ulcer and gastric cancer

Helicobacter pylori (H. pylori) infection underlies gastric ulcer disease, gastric cancer and duodenal ulcer disease. The disease expression reflects the pattern and extent of gastritis/gastric atrophy (i.e., duodenal ulcer with non-atrophic and gastric ulcer and gastric cancer with atrophic gastritis). Gastric and duodenal ulcers and gastric cancer have been known for thousands of years. Ulcers are generally non-fatal and until the 20^th century were difficult to diagnose. However, the presence and pattern of gastritis in past civilizations can be deduced based on the diseases present. It has been suggested that gastric ulcer and duodenal ulcer both arose or became more frequent in Europe in the 19^th century. Here, we show that gastric cancer and gastric ulcer were present throughout the 17^th to 19^th centuries consistent with atrophic gastritis being the predominant pattern, as it proved to be when it could be examined directly in the late 19^th century. The environment before the 20^th century favored acquisition of H. pylori infection and atrophic gastritis (e.g., poor sanitation and standards of living, seasonal diets poor in fresh fruits and vegetables, especially in winter, vitamin deficiencies, and frequent febrile infections in childhood). The latter part of the 19^th century saw improvements in standards of living, sanitation, and diets with a corresponding decrease in rate of development of atrophic gastritis allowing duodenal ulcers to become more prominent. In the early 20^th century physician’s believed they could diagnose ulcers clinically and that the diagnosis required hospitalization for “surgical disease” or for “Sippy” diets. We show that while H. pylori remained common and virulent in Europe and the United States, environmental changes resulted in changes of the pattern of gastritis producing a change in the manifestations of H. pylori infections and subsequently to a rapid decline in transmission and a rapid decline in all H. pylori-related diseases.

Risk factors for intestinal metaplasia in concomitant gastric and duodenal ulcer disease

The aim of this study was to estimate the prevalence and risk factors of intestinal metaplasia (IM) in concomitant gastric and duodenal ulcer (CGDU) disease by retrospectively reviewing consecutive patients who had undergone esophagogastroduodenal endoscopy. Patients who received the endoscopic diagnosis of CGDU disease were selected for analysis and the recorded demographic, endoscopic, clinical and outcome data, including data on the development of IM, were extracted. Associations of the various parameters with IM were estimated by logistic regression analysis and described by the odds ratio (OR) with a 95% confidence interval (CI). Among the total 204,073 consecutive patients screened, 2,397 (1.2%) were diagnosed with CGDU disease. Following application of the exclusion criteria, a total of 2,149 cases were included in the study. The IM prevalence was 8.4%, represented by 153 mild cases, 26 moderate cases and one severe case. Multivariate analysis identified age ≥50 years (OR=2.606, 95% CI=1.889-3.597, χ²=34.000, P<0.001), ulcer at the gastric incisura (OR=2.644, 95% CI=1.926-3.630, χ²=36.142, P<0.001) and Helicobacter pylori (H. pylori) infection (OR=2.338, 95% CI=1.573-3.474, χ²=17.648, P<0.001) as independent risk factors for the development of IM. In addition, the moderate and severe IM grades were more frequently detected in males than in females (18.8% vs. 5.8%; OR=3.769, 95% CI=1.083-13.121, χ²=4.887, P=0.036). IM in patients with CGDU disease is not uncommon. CGDU patients with ongoing H. pylori infection, gastric incisura involvement, older age and/or male gender may be at a higher risk of IM.

Staging of intestinal- and diffuse-type gastric cancers with the OLGA and OLGIM staging systems

BACKGROUND

Operative link on gastritis assessment (OLGA) and Operative link on gastric intestinal metaplasia assessment (OLGIM) staging systems have been proposed for gastric cancer (GC) risk estimation.

AIM

To validate the OLGA and OLGIM staging systems in a region with high risk of GC.

METHODS

This retrospective study included 474 GC patients and age- and sex-matched health screening control persons in a cancer centre hospital. We classified gastritis patterns according to the OLGA and OLGIM systems using the histological database that a pathologist prospectively evaluated using the updated Sydney system. GC risk according to the OLGA and OLGIM stages was evaluated using logistic regression analysis.

RESULTS

More GC patients had OLGA stages III-IV (46.2%) than controls (26.6%, P < 0.001), particularly among patients with intestinal-type GCs (62.2%) compared with diffuse-type GCs (30.9%). OLGA stages III and IV were significantly associated with increased risk of GC [odds ratios (ORs), 2.09; P = 0.008 and 2.04; P = 0.014 respectively] in multivariate analysis. The association was more significant for intestinal-type (ORs, 4.76; P = 0.001 and 4.19; P = 0.002 respectively), but not diffuse-type GC. OLGIM stages from I to IV were significantly associated with increased risk of both intestinal-type (ORs, 3.64, 5.15, 7.89 and 13.20 respectively) and diffuse-type GC (ORs, 1.84, 2.59, 5.08 and 6.32 respectively) with a significantly increasing trend.

CONCLUSION

As high OLGA and OLGIM stages are independent risk factors for gastric cancer, the staging systems may be useful for risk assessment in high-risk regions, especially for intestinal-type gastric cancer.

Genetic factors related to gastric cancer susceptibility identified using a genome-wide association study

Gastric cancer (GC) is one of the major malignant diseases worldwide, especially in Asia, where Japan and Korea have the highest incidence in the world. Gastric cancer is classified into intestinal and diffuse types. While the former is almost absolutely caused by Helicobacter pylori infection as the initial insult, the latter seems to include cases in which the role of infection is limited, if any, and a contribution of genetic factors is anticipated. Previously, we performed a genome-wide association study (GWAS) on diffuse-type GC by using single nucleotide polymorphisms (SNP) catalogued for Japanese population (JSNP), and identified a prostate stem cell antigen (PSCA) gene encoding a glycosylphosphatidylinositol-anchored cell surface antigen as a GC susceptibility gene. From the second candidate locus identified using the GWAS, 1q22, we found the Mucin 1 (MUC1) gene encoding a cell membrane-bound mucin protein as another gene related to diffuse-type GC. A two-allele analysis based on risk genotypes of the two genes revealed approximately 95% of Japanese population have at least one of the two risk genotypes, and approximately 56% of the population have both risk genotypes. The two-SNP genotype might offer ample room to further stratify a high GC risk subpopulation in Japan and Asia by adding another genetic and/or non-genetic factor. Recently, a GWAS on the Chinese population disclosed an additional three GC susceptibility loci: 3q13.31, 5p13.1 and 10q23.

Follow-up of intestinal metaplasia in the stomach: When, how and why

Gastric cancer remains the second most frequent cause of cancer-related mortality in the world. Screening programs in some Asian countries are impractical in the majority of other countries worldwide. Therefore, follow-up of precancerous lesions is advisable for secondary gastric cancer prevention. Intestinal metaplasia (IM) is recognized as a precancerous lesion for gastric cancer, increasing the risk by 6-fold. IM is highly prevalent in the general population, being detected in nearly 1 of every 4 patients undergoing upper endoscopy. The IM prevalence rate is significantly higher in patients with Helicobacter pylori (H. pylori) infection, in first-degree relatives of gastric cancer patients, in smokers and it increases with patient age. IM is the “breaking point” in the gastric carcinogenesis cascade and does not appear to regress following H. pylori eradication, although the cure of infection may slow its progression. Gastric cancer risk is higher in patients with incomplete-type IM, in those with both antral and gastric body involvement, and the risk significantly increases with IM extension over 20% of the gastric mucosa. Scheduled endoscopic control could be cost-effective in IM patients, depending on the yearly incidence of gastric cancer in IM patients, the stage of gastric cancer at diagnosis discovered at surveillance, and the cost of endoscopy. As a pragmatic behavior, yearly endoscopic control would appear justified in all IM patients with at least one of these conditions: (1) IM extension > 20%; (2) the presence of incomplete type IM; (3) first-degree relative of gastric cancer patients; and (4) smokers. In the remaining IM patients, a less intensive (2-3 years) could be proposed.