Autofluorescence imaging for predicting development of metachronous gastric cancer after Helicobacter pylori eradication

Factors influencing occurrence of metachronous gastric cancer after endoscopic resection: a systematic review and meta-analysis

BACKGROUND/AIMS

Metachronous gastric cancer (MGC) can occur after endoscopic resection for gastric cancer. Further studies on factors other than Helicobacter pylori infection are needed. This systematic review and meta-analysis aimed to evaluate risk factors for metachronous recurrence of endoscopically resected gastric cancer.

METHODS

We searched medical literature published by February 2023 and identified patients with MGC after endoscopic resection for gastric cancer. The occurrence of MGC and the presence of intestinal metaplasia (IM), severe atrophic gastritis (AG), and H. pylori infection were quantitatively analyzed.

RESULTS

We identified 2,755 patients from nine cohort studies who underwent endoscopic resection for gastric cancer by 2018. Those with severe AG or presence of IM had a significantly higher incidence of MGC than those without (RR 2.00, 95% CI 1.35-2.98, I2 = 52% for severe atrophy on antrum; RR 7.08, 95% CI 3.63-13.80, I2 = 0% for antral IM). Absolute risk difference of MGC occurrence was 7.1% in those with severe AG and 9.2% in those with IM. The difference in incidence rate per 1,000 person-years was 17.5 person-years for those with severe AG and 24.7 person-years for those with IM. However, H. pylori eradication did not significantly affect the occurrence of MGC (RR 1.18, 95% CI 0.88-1.59, I2 = 10%).

CONCLUSION

Gastric cancer patients with severe AG or presence of IM had a 2.0-fold or 7.0-fold higher risk of MGC occurrence after endoscopic resection than those without, respectively. They need more stringent follow-up to monitor MGC occurrences (CRD42023410940).

Metachronous Multiple Gastric Cancer Discovered as Endoscopic Curability C2 during Regular Follow-Up after Gastric Endoscopic Submucosal Dissection

INTRODUCTION

The objective of this study was to clarify characteristics of metachronous endoscopic curability C2 (eCura C2) cancer during post-endoscopic submucosal dissection (ESD) follow-up.

METHODS

Of 4,355 gastric lesions treated by ESD at our hospital during 2005-2021, 657 were metachronous. After excluding lesions found ≥2 years since the prior examination or in the gastric remnant, the remaining 515 were analyzed. Study 1: We compared 35 eCura C2 cancers and 480 eCura A-C1 cancers. Study 2: Endoscopic findings of the 35 lesions were examined to determine why they had been missed.

RESULTS

Mean tumor size was larger (34.0 mm vs. 12.1 mm, p < 0.01) and the proportions of mixed-type and poorly differentiated cancers were higher (highly:mixed:poorly, 34.3:57.1:8.6 vs. 94.2:5.0:0.8, p < 0.01) in the eCura C2 group. Study 2: At the prior examination, 4 lesions were noticed but considered benign, 2 lacked sufficient imaging, 19 were detectable on imaging but missed, and 10 were not detectable on imaging. Over half the lesions that were detectable but missed at the prior examination were in the lesser curvature, many being type IIa-IIb lesions with color similar to the background mucosa. All lesions not detectable on imaging at the prior examination were mixed-type or poorly differentiated type.

DISCUSSION

Metachronous cancer detected as eCura C2 cancers was significantly larger, and a significantly higher proportion was mixed-type or poorly differentiated cancers, compared with eCura A-C1 cancers. Possible reasons why these lesions were missed include rapid progression of mixed-type and poorly differentiated cancers, and poor recognition that lesions showing only slight color changes may be present at the lesser curvature.

In vivo grading of lipids in fatty liver by near-infrared autofluorescence and reflectance

The prevalence of nonalcoholic fatty liver (NAFLD) is rapidly increasing worldwide. When untreated, it may lead to complications such as liver cirrhosis or hepatocarcinoma. The diagnosis of NAFLD is usually obtained by ultrasonography, a technique that can underestimate its prevalence. For this reason, physicians aspire for an accurate, cost-effective, and noninvasive method to determine both the presence and the specific stage of the NAFLD. In this paper, we report an integrated approach for the quantitative estimation of the density of triglycerides in the liver based on the use of autofluorescence and reflectance signals generated by the abdomen of obese C57BL6/J mice. Singular value decomposition is applied to the generated spectra and its corresponding regression model provided a determination coefficient of 0.99 and a root mean square error of 240 mg/dl. This, in turn, enabled the quantitative imaging of triglycerides density in the livers of mice under in vivo conditions.

Risk and prognostic factors of invasive gastric cancer detection during surveillance endoscopy: Multi-institutional cross-sectional study

OBJECTIVES

Esophagogastroduodenoscopy (EGD) is important for the detection of curable gastric cancer (GC). However, there are no appropriate surveillance data during routine endoscopic inspections. This study aimed to clarify the risk factors of pT1b or deeper GC detection during surveillance endoscopy.

METHODS

This was a retrospective, multicenter, cross-sectional study conducted in 15 Japanese hospitals. We retrospectively analyzed patients with GC who had previously undergone surveillance endoscopy at each institution from January 2014 to March 2020. Patients who had undergone gastrectomy, non-infection of Helicobacter pylori (Hp), and those with intervals <3 months or >10 years from a previous endoscopy were excluded.

RESULTS

In total, 1085 patients with GCs detected during surveillance endoscopy were enrolled. The multivariate logistic analysis revealed that current Hp infection (odds ratio [OR] 2.18; 95% confidence interval [CI] 1.50-3.16) and a surveillance interval of >1.5 years (OR 1.96; 95% CI 1.35-2.84) were independent risk factors for pT1b or deeper GC. The 5-year disease-specific survival (5y-DSS) rate of GC was significantly lower in patients with surveillance interval of >1.5 years than in those with surveillance interval of ≤1.5 years (93.7% vs. 98.3%, P < 0.001). Similarly, the 5y-DSS rate of GC was significantly lower in patients with active Hp infection than in those without (93.7% vs. 99.4%, P < 0.001).

CONCLUSION

In this study, a surveillance interval of >1.5 years and current Hp infection were independent risk factors for detecting pT1b or deeper GC. Additionally, these factors were poor prognostic factors of the detected GC during surveillance endoscopy.

Kyoto classification of gastritis: Advances and future perspectives in endoscopic diagnosis of gastritis

This editorial provides an update of the recent evidence on the endoscopy-based Kyoto classification of gastritis, clarifying the shortcomings of the Kyoto classification, and providing prospects for future research, with particular focus on the histological subtypes of gastric cancer (GC) and Helicobacter pylori (H. pylori) infection status. The total Kyoto score is designed to express GC risk on a score ranging from 0 to 8, based on the following five endoscopic findings: Atrophy, intestinal metaplasia (IM), enlarged folds (EF), nodularity, and diffuse redness (DR). The total Kyoto score reflects H. pylori status as follows: 0, ≥ 2, and ≥ 4 indicate a normal stomach, H. pylori-infected gastritis, and gastritis at risk for GC, respectively. Regular arrangement of collecting venules (RAC) predicts non-infection; EF, nodularity, and DR predict current infection; map-like redness (MLR) predicts past infection; and atrophy and IM predict current or past infection. Atrophy, IM, and EF all increase the incidence of H. pylori-infected GC. MLR is a specific risk factor for H. pylori-eradicated GC, while RAC results in less GC. Diffuse-type GC can be induced by active inflammation, which presents as EF, nodularity, and atrophy on endoscopy, as well as neutrophil and mononuclear cell infiltration on histology. In contrast, intestinal-type GC develops via atrophy and IM, and is consistent between endoscopy and histology. However, this GC risk-scoring design needs to be improved.

Detection of Early Gastric Cancer after Helicobacter pylori Eradication

BACKGROUND

Based on evidence that Helicobacter pylori eradication reduces the development of gastric cancer and other diseases such as peptic ulcer, eradication therapy has prevailed. However, gastric cancer can develop even after successful eradication.

SUMMARY

In this review article, we searched for studies that identified the characteristics of primary and metachronous gastric cancers after H. pylori eradication, the risk factors for the development of these cancers after successful H. pylori eradication, and whether image-enhanced endoscopy is useful for diagnosing gastric cancer after eradication. A gastritis-like appearance is seen as a characteristic endoscopic finding, which corresponds to an epithelium with low-grade atypia - also known as nonneoplastic epithelium - covering the surface of the cancerous glands. This finding may make endoscopic detection of early gastric cancer difficult after H. pylori eradication. Similar risk factors, such as the male sex, endoscopic atrophy, histologic intestinal metaplasia, and late eradication, have been reported as predictors for the development of both primary and metachronous gastric cancers. Image-enhanced endoscopy, such as linked color imaging, may be useful for the detection and risk stratification of gastric cancer after eradication. Key Messages: Based on these findings, we believe that effective surveillance of high-risk patients leads to early detection of gastric cancer in the era of H. pylori eradication.

Diagnosis of advanced gastric cancer using image enhancement and autofluorescence imaging systems

INTRODUCTION

The indication of laparoscopic gastrectomy for advanced cases such as serosal invasion or peritoneal dissemination is still controversial. We report the clinical experiences of laparoscopic diagnosis with image enhancement and autofluorescence (AF) systems for laparoscopic gastric cancer surgery.

METHODS

The image enhancement system was introduced to 164 patients who underwent laparoscopic gastric cancer surgery as the AF group. The control group was defined as 165 cases who underwent bright light observation without the image enhancement system. The operative findings were recorded during surgery. All image findings were retrospectively compared with the pathological findings. Furthermore, the relationship between the image and pathological findings for peritoneal dissemination and subserosal invasion was evaluated.

RESULTS

This study included 329 patients, divided into the control group of 165 patients (50.2%) and the AF group of 164 patients (49.8%). There was no statistically significant difference in patient background between the two groups. In seven cases of peritoneal dissemination, AF was positive, and macroscopic abnormal vascularization was detected. The sensitivity, specificity, and positive and negative predictive values were 100%, 99.4%, 87.5%, and 100%, respectively. In 29 cases of serosal invasion, AF was positive, and macroscopic abnormal vascularization was detected. In the detection accuracy of subserosal invasion, the sensitivity, specificity, and positive and negative predictive values were 75.7%, 97.6%, 90.3%, and 93.2%, respectively.

CONCLUSION

The image enhancement with the AF system is useful for the laparoscopic intraoperative diagnosis of serosal invasion and peritoneal dissemination for advanced gastric cancer.

Long-term outcomes after endoscopic submucosal dissection for differentiated-type early gastric cancer that fulfilled expanded indication criteria: A prospective cohort study

BACKGROUND AND AIM

Endoscopic resection for early gastric cancer (EGC) is widely performed. However, there is still a paucity of strong evidence regarding long-term outcomes after endoscopic submucosal dissection (ESD) for the expanded indication criteria of the Japanese guidelines (ver. 2010).

METHODS

Endoscopic submucosal dissection was performed in patients with EGC that met the expanded indication criteria: (i) cT1a, differentiated-type EGC of 2 to 5 cm, ulcer negative or (ii) cT1a, differentiated-type EGC of ≤3 cm, ulcer positive. Patients whose pathological examination fulfilled the curative resection criteria were then enrolled in this cohort study: negative vertical margin, negative lymphovascular invasion, and (i) pT1a, differentiated-type, and ulcer negative; (ii) pT1a, differentiated-type, ≤3 cm, and ulcer positive; or (iii) pT1b1 (<500-μm submucosal invasion), differentiated-type, and ≤3 cm. Patients with only a positive horizontal margin as a noncurative factor were included for follow-up.

RESULTS

From September 2003 to February 2012, a total of 356 patients underwent ESD, and 214 were enrolled in the survival analysis. One hundred twenty patients (56%) had >2 cm in diameter and ulcer-negative lesions, and 94 (44%) had ≤3 cm and ulcer-positive lesions. The vital status at 5 years after ESD was confirmed in all (100%) patients. No local or metastatic recurrence was detected; however, 26 metachronous gastric cancers developed, and 1 patient died of metachronous gastric cancer. The 5-year disease-specific and overall survival rates were 99.5% (95% confidence interval [CI], 97.2%-100%) and 93.9% (95% CI, 89.8%-96.4%), respectively.

CONCLUSION

ESD for EGC that fulfills the expanded criteria is feasible and shows favorable long-term outcomes.

Increased incidence of metachronous gastric neoplasm after endoscopic resection in patients with synchronous gastric neoplasm

Background

Recurrence risk is a major concern after endoscopic resection (ER) of gastric neoplasms. This study was to compare metachronous risk in patients with and without synchronous neoplasms after complete ER.

Methods

After ER for gastric neoplasms, patients were divided into those with and without synchronous neoplasm. The metachronous risk of gastric neoplasms was compared between the two groups.

Results

After ER of 678 cancers and 891 adenomas, synchronous neoplasm was found in 11.8% of cancers and 11.4% of adenomas. In the multiple (n = 182) and the single group (n = 1387), metachronous neoplasms occurred in 18.1 and 8.6%, respectively (HR 2.40; 95% CI, 1.62–3.34). When the pathology of the recurred lesion was limited to cancer, metachronous risk was also significantly higher in the multiple than in the single group (HR, 2.2; 95% CI, 1.17–3.85). In the recurred pathology of the multiple group, cancer development was frequently observed in patients with cancer compared to those with only adenomas in the synchronous lesion (67.0% vs. 13.0%, respectively; P = 0.023).

Conclusions

This study demonstrated that metachronous risk was significantly higher in patients with synchronous gastric neoplasms after ER. Therefore, meticulous examination is important in patients with synchronous neoplasm.

Gastric Mucosal Microarchitectures Associated with Irreversibility with Helicobacter pylori Eradication and Downregulation of Micro RNA (miR)-124a

To investigate the molecular mechanisms of gastric carcinogenesis after Helicobacter pylori (H. pylori) eradication, expression of miR-124a, miR-34b, and miR-34c was examined in nonneoplastic gastric specimens after successful H. pylori eradication. The magnifying narrow-band imaging (NBI) endoscopic features of gastric mucosa were also examined. The atrophic type, an informative endoscopic feature for histological intestinal metaplasia, showed lower expression of miR-124a. Lower expression of miR-124a correlated with hypermethylation of the miR-124a3 locus. The atrophic type represents gastric microarchitectures associated with irreversibility with H. pylori eradication and downregulation of miR-124a.

Time trends in the incidence of esophageal adenocarcinoma, gastric adenocarcinoma, and superficial esophagogastric junction adenocarcinoma

BACKGROUND

In Japan, the incidence of esophageal adenocarcinoma (EAC) and esophagogastric junction (EGJ) adenocarcinoma is expected to increase and that of gastric adenocarcinoma (GAC) is expected to decrease due to Westernization of the diet and the decreasing prevalence of Helicobacter pylori infection. However, few reports about these trends have included the latest data, and no reports about the time trend in the incidence of EGJ adenocarcinoma have focused on the etiologies (gastric cardia adenocarcinoma or EAC, including Barrett's adenocarcinoma). We therefore investigated the time trends in the incidence of these cancers by including the latest data.

METHODS

First, we investigated the time trends in EAC and GAC using population-based cancer registry data in Osaka Prefecture (1985-2014). We then investigated the time trend in superficial EGJ adenocarcinoma with clinicopathological features at Osaka International Cancer Institute (2006-2017).

RESULTS

From 1985 to 2014 in Osaka Prefecture, the incidence of EAC gradually increased in both sexes, while that of GAC in men did not significantly change and that in women decreased. The ratio of the EAC/GAC incidence increased 3.5 times in men and 1.8 times in women. In the secondary time trend survey for EGJ adenocarcinoma, the numbers of patients with endoscopic Barrett's esophagus and those without gastric mucosal atrophy increased, and the number of patients with lesions located above the EGJ line and histologically diagnosed as Barrett's adenocarcinoma increased.

CONCLUSIONS

The incidence of EAC and superficial EGJ adenocarcinoma with characteristics similar to those of EAC, including Barrett's adenocarcinoma, might be increasing.

Effects of Helicobacter pylori eradication for metachronous gastric cancer prevention: a randomized controlled trial

BACKGROUND AND AIMS

Whether eradication of Helicobacter pylori reduces the incidence of metachronous gastric cancer (MGC) is still debatable. We aimed to evaluate the long-term effect of H pylori eradication on the development of MGC after endoscopic gastric tumor resection.

METHODS

We undertook an open-label, prospective, randomized controlled trial at a tertiary hospital in Seoul, Korea. Participants were recruited during April 2005 to February 2011 and followed until December 2016. We assigned 898 patients with H pylori infection treated with endoscopic resection (ER) for gastric dysplasia or early gastric cancer to receive (n =442) or not receive (n =456) eradication therapy using a random-number chart. Eradication group patients received oral omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg twice daily for a week, whereas control group patients received no H pylori treatment. The primary outcome was the incidence of MGC (intention-to-treat analysis).

RESULTS

The 877 patients who attended ≥1 follow-up examination (eradication group, 437; control group, 440) were analyzed. Median follow-up was 71.6 months (interquartile range, 42.1-90.0). MGC developed in 18 (4.1%) eradication and 36 (8.2%) control group patients (log-rank test, P = .01). In our yearly analysis, the effect of eradication showed a significant difference in 5 years after allocation (log-rank test, P = .02). The adjusted hazard ratio for the control group was 2.02 (95% CI, 1.14-3.56; P = .02), compared with the eradication group.

CONCLUSIONS

H pylori eradication significantly reduces the incidence of MGC after ER of gastric tumors and should be considered for H pylori-positive gastric tumor patients treated with ER. (Clinical trial registration number: NCT01510730.).

Characteristics and predictors of gastric cancer after Helicobacter pylori eradication

Helicobacter pylori (H. pylori) eradication can reduce gastric cancer. However, gastric cancer still develops after eradication, and cases who received eradication therapy are increasing. In this study, we have reviewed the characteristics and predictors of primary gastric cancer developing after H. pylori eradication. In terms of the characteristics, endoscopic, histologic, and molecular characteristics are reported. Endoscopically, gastric cancer after eradication is often depressed-type and shows a gastritis-like appearance, which sometimes makes the diagnosis difficult. Histologically, most gastric cancer after eradication is intestinal type, and non-neoplastic epithelium, also called epithelium with low-grade atypia, is frequently seen over the tumor, which is presumably the cause of the endoscopic gastritis-like appearance. As for molecular characteristics, some markers, such as Ki67, MUC2, and Wnt5a expression, are lower in cancer from patients in whom H. pylori has been eradicated. In terms of predictors, several Japanese studies have reported that severe endoscopic atrophy at eradication is a risk factor for gastric cancer development. Histologic intestinal metaplasia, especially in the corpus, and long-term use of proton pump inhibitors, are also reported as risk factors for gastric cancer after H. pylori eradication. These studies on the characteristics and predictors of gastric cancer development will become the cornerstone for establishing a novel surveillance program based on the gastric cancer risk stratification specific to H. pylori-eradicated patients.

Association between gastric cancer and the Kyoto classification of gastritis

BACKGROUND AND AIM

Histological gastritis is associated with gastric cancer, but its diagnosis requires biopsy. Many classifications of endoscopic gastritis are available, but not all are useful for risk stratification of gastric cancer. The Kyoto Classification of Gastritis was proposed at the 85th Congress of the Japan Gastroenterological Endoscopy Society. This cross-sectional study evaluated the usefulness of the Kyoto Classification of Gastritis for risk stratification of gastric cancer.

METHODS

From August 2013 to September 2014, esophagogastroduodenoscopy was performed and the gastric findings evaluated according to the Kyoto Classification of Gastritis in a total of 4062 patients. The following five endoscopic findings were selected based on previous reports: atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness.

RESULTS

A total of 3392 patients (1746 [51%] men and 1646 [49%] women) were analyzed. Among them, 107 gastric cancers were diagnosed. Atrophy was found in 2585 (78%) and intestinal metaplasia in 924 (27%). Enlarged folds, nodularity, and diffuse redness were found in 197 (5.8%), 22 (0.6%), and 573 (17%), respectively. In univariate analyses, the severity of atrophy, intestinal metaplasia, diffuse redness, age, and male sex were associated with gastric cancer. In a multivariate analysis, atrophy and male sex were found to be independent risk factors. Younger age and severe atrophy were determined to be associated with diffuse-type gastric cancer.

CONCLUSION

Endoscopic detection of atrophy was associated with the risk of gastric cancer. Thus, patients with severe atrophy should be examined carefully and may require intensive follow-up.

Magnifying NBI Patterns of Gastric Mucosa After Helicobacter pylori Eradication and Its Potential Link to the Gastric Cancer Risk

BACKGROUND

Gastric cancer develops after successful H. pylori eradication in patients with severe atrophic gastritis. We classified atrophic and non-atrophic mucosa of gastric body using magnifying NBI endoscopy in patients after successful H. pylori eradication.

MATERIALS AND METHODS

One hundred and twenty-five patients after successful H. pylori eradication (median period after eradication: 36 months) were enrolled. Magnifying NBI patterns in the uninvolved gastric body were divided into the following: restored-small, round pits, accompanied with honeycomb-like subepithelial capillary networks; atrophic-well-demarcated oval or tubulovillous pits with clearly visible coiled or wavy vessels. The subjects were also classified into the three types: Grade 0-restored pattern is shown in all or almost the entire area of gastric body; Grade 1-mixture of restored and atrophic pattern, there is a considerable portion of the atrophic area in the lesser curvature; Grade 2-atrophic pattern is shown in all or almost the entire area of the gastric body.

RESULTS

Sensitivity and specificity for atrophic type for detection of histological intestinal metaplasia were 95.9 and 98.3%, respectively. No association was observed between the prevalence of Grades 0, 1 and 2 and duration after eradication, while grades 1 and 2 were significantly frequent in gastric cancer patients diagnosed both before (27/35: 77%) and after (23/31: 74%) eradication, compared to the cancer-free subjects (15/59: 25%) (P < 0.001). The grades 1 and 2 were also common in patients who underwent H. pylori eradication for gastric ulcer.

CONCLUSIONS

Magnifying the NBI pattern well correlates with pathological status of gastric mucosa after H. pylori eradication and may predict gastric cancer occurrence.

Morphologic characterization of residual DNA methylation in the gastric mucosa after Helicobacter pylori eradication

Residual DNA methylation in the gastric mucosa after Helicobacter pylori (H. pylori) eradication may have a role in gastric carcinogenesis. We examined the association between morphologic features and promoter methylation status of non-neoplastic gastric mucosa especially after H. pylori eradication. A total of 140 gastric specimens from 99 participants who had at least 6 months of post-eradication period were examined. The magnifying narrow-band imaging (NBI) endoscopic feature of gastric mucosa was divided into two types: restored-small, round pits, accompanied with honeycomb-like subepithelial capillary networks; atrophic-well-demarcated oval or tubulovillous pits with clearly visible coiled or wavy vessels. Methylation status of five candidate genes (MYOD1, SLC16A12, IGF2, RORA, and PRDM5) were examined by bisulfite pyrosequencing. The atrophic type, informative endoscopic features of intestinal metaplasia, demonstrated higher methylation levels in all five genes compared to the restored type (all P < 0.0001). In the restored type, methylation levels were significantly lower among the samples with longer post-eradication period (for all genes, P < 0.0001), which was not observed in atrophic type (for all genes, P > 0.1). Multivariate analysis demonstrated that atrophic type or presence of intestinal held an independent factor for hyper methylation (odds ratio: 24.69, 95% confidence interval: 6.95-87.76, P < 0.0001). The atrophic type by the magnifying NBI and presence of intestinal metaplasia are the morphologic characteristics of residual DNA methylation of after H. pylori eradication, regardless of the post-eradication period and it might be considered as the epigenetic irreversible point with H. pylori eradication.

MicroRNA‑499 rs3746444 A/G polymorphism functions as a biomarker to predict recurrence following endoscopic submucosal dissection in primary early gastric cancer

The aim of the present study was to investigate the molecular mechanism, including the potential regulatory and signaling pathways, of platelet‑derived growth factor receptor β (PDGFRB), which underlies the recurrence of early gastric cancer (EGC) following endoscopic submucosal dissection (ESD). Online microRNA (miRNA) target prediction tools were used, which identified PDGFRB as the candidate target gene of miR‑499a in gastric cancer cells, and PFGRBR was then confirmed as the direct gene using a luciferase reporter assay system. The Kaplan‑Meier method was used to plot recurrence‑free curves, which were compared between genotype groups. A negative regulatory association between miR‑499a and PDGFRB was established by investigating the relative luciferase activity at different concentrations of miR‑499a mimics. Furthermore, as the rs3746444 polymorphism has been previously reported to interfere with the expression of miR‑499a, the present study investigated the expression levels of different genotypes, including TT (n=20), TC (n=9) and CC (n=3), the results of which supported the hypothesis that the presence of the minor allele (C) of the rs3746444 polymorphism compromised the expression of miR‑499a. The present study also performed polymerase chain reaction and western blot analyses to examine the mRNA and protein expression levels of PFGRBR among different genotypes or cells treated with different concentrations of miR‑499a mimics/inhibitors, which indicated the negative regulatory association between miR‑499a and PDGFRB. The present study also investigated the relative viabilities of EGC cells transfected with miR‑499a mimics (50 and 100 nM) and miR‑499a inhibitors (100 nM), and confirmed that miR‑499a negatively interfered with the viability of the EGC cells. The miR‑499a rs3746444 polymorphism was also recognized as a biomarker to predict recurrence following ESD in patients with EGC via analyzing the recurrence‑free rates among patients with EGC with different genotypes. The results showed that PDGFRB was validated as a target of miR‑499a, and rs3746444 was identified as a potential biomarker to predict the recurrence of EGC following ESD.

Investigation of mucosal pattern of gastric antrum using magnifying narrow-band imaging in patients with chronic atrophic fundic gastritis

BACKGROUND

Magnifying narrow-band imaging (M-NBI) can reportedly help predict the presence and distribution of atrophy and intestinal metaplasia in the gastric corpus. However, the micro-mucosal pattern of the antrum shown by M-NBI differs from that of the corpus. We studied the distribution and histology of the micro-mucosal pattern in the antrum based on magnifying endoscopy.

METHODS

Endoscopic images of the greater curvature of the antrum were evaluated in 50 patients with chronic atrophic fundic gastritis (CAFG). The extent of CAFG was evaluated by autofluorescence imaging. The micro-mucosal pattern was evaluated by M-NBI and classified into groove and white villiform types. The localization of white villiform type mucosa was classified into three types in relation to the areae gastricae: null, central, and segmental types. Biopsies were taken from regions showing different micro-mucosal patterns. Associations among the extent of CAFG, micro-mucosal pattern, and histology were examined.

RESULTS

As the extent of CAFG increased, the proportion of white villiform type mucosa increased, whereas that of groove type mucosa decreased (P=0.022). In patients with extensive CAFG, most of the areae gastricae was composed of the segmental or central type of white villiform type mucosa (P=0.044). The white villiform type mucosa had significantly higher grades of atrophy (P=0.002) and intestinal metaplasia (P<0.001) than did the groove type mucosa.

CONCLUSION

White villiform type mucosa is indicative of atrophy and intestinal metaplasia in the gastric antrum. It extends to the whole or central part of the areae gastricae as CAFG becomes more extensive.

Risk Factors for Metachronous Gastric Neoplasms in Patients Who Underwent Endoscopic Resection of a Gastric Neoplasm

Background/Aims

To identify the risk factors for metachronous gastric neoplasms in patients who underwent an endoscopic resection of a gastric neoplasm.

Methods

We prospectively collected clinicopathologic data and measured the methylation levels of HAND1, THBD, APC, and MOS in the gastric mucosa by methylation-specific real-time polymerase chain reaction in patients who underwent endoscopic resection of gastric neoplasms.

Results

A total of 257 patients with gastric neoplasms (113 low-grade dysplasias, 25 high-grade dysplasias, and 119 early gastric cancers) were enrolled. Metachronous gastric neoplasm developed in 7.4% of patients during a mean follow-up of 52 months. The 5-year cumulative incidence of metachronous gastric neoplasm was 4.8%. Multivariate analysis showed that moderate/severe corpus intestinal metaplasia and family history of gastric cancer were independent risk factors for metachronous gastric neoplasm development; the hazard ratios were 4.12 (95% confidence interval [CI], 1.23 to 13.87; p=0.022) and 3.52 (95% CI, 1.09 to 11.40; p=0.036), respectively. The methylation level of MOS was significantly elevated in patients with metachronous gastric neoplasms compared age- and sex-matched patients without metachronous gastric neoplasms (p=0.020).

Conclusions

In patients who underwent endoscopic resection of gastric neoplasms, moderate/severe corpus intestinal metaplasia and a family history of gastric cancer were independent risk factors for metachronous gastric neoplasm, and MOS was significantly hypermethylated in patients with metachronous gastric neoplasms.

Surveillance of patients with gastric precancerous conditions

Intestinal-type gastric adenocarcinoma arises from a multistep process starting with Helicobacter pylori infection followed by gastric atrophy, gastric intestinal metaplasia and dysplasia. Indeed, patients with gastric precancerous conditions or lesions (GPC) are at increased risk to develop gastric cancer even in regions with low incidence. Thus, the identification and surveillance of a high risk subgroup could lead to the diagnosis of cancer at early stage and improve survival. However, both endoscopic and histological accuracy and interobserver agreement in the diagnosis of GPC are still far from optimal. Also, there are conceptual differences between the West and the East in the diagnosis and surveillance of patients. In the former, multiple gastric biopsies are still recommended but Eastern gastroenterologists select patients to surveillance according to the results of endoscopy or serology. In this literature review we describe the cascade of GPC and we highlight the differences between eastern and western clinical practice.

Usefulness of Endoscopic Imaging to Visualize Regional Alterations in Acid Secretion of Noncancerous Gastric Mucosa after Helicobacter pylori Eradication

Purpose

Endoscopic diagnosis of gastric cancer (GC) that emerges after eradication of Helicobacter pylori may be affected by unique morphological changes. Using comprehensive endoscopic imaging, which can reveal biological alterations in gastric mucosa after eradication, previous studies demonstrated that Congo red chromoendoscopy (CRE) might clearly show an acid non-secretory area (ANA) with malignant potential, while autofluorescence imaging (AFI) without drug injection or dyeing may achieve early detection or prediction of GC. We aimed to determine whether AFI might be an alternative to CRE for identification of high-risk areas of gastric carcinogenesis after eradication.

Materials and Methods

We included 27 sequential patients with metachronous GC detected during endoscopic surveillance for a mean of 82.8 months after curative endoscopic resection for primary GC and eradication. After their H. pylori infection status was evaluated by clinical interviews and ¹³C-urea breath tests, the consistency in the extension of corpus atrophy (e.g., open-type or closed-type atrophy) between AFI and CRE was investigated as a primary endpoint.

Results

Inconsistencies in atrophic extension between AFI and CRE were observed in 6 of 27 patients, although CRE revealed all GC cases in the ANA. Interobserver and intraobserver agreements in the evaluation of atrophic extension by AFI were significantly less than those for CRE.

Conclusions

We demonstrated that AFI findings might be less reliable for the evaluation of gastric mucosa with malignant potential after eradication than CRE findings. Therefore, special attention should be paid when we clinically evaluate AFI findings of background gastric mucosa after eradication (University Hospital Medical Information Network Center registration number: UMIN000020849).

A Possible Link between Gastric Mucosal Atrophy and Gastric Cancer after Helicobacter pylori Eradication

Background

The effect of H. pylori eradication in gastric cancer prevention can be attributed to the improvement of atrophic gastritis, which is a known risk of gastric cancer. However, gastric cancer has also been diagnosed after long-term H. pylori eradication. This study aimed to clarify the association between gastric atrophy and gastric cancer after H. pylori eradication, including its clinicopathological features.

Methods

A total of 55 consecutive patients with 64 early gastric cancers (EGCs) diagnosed after H. pylori eradication were enrolled. The degree of endoscopic atrophy and the histological degrees of mononuclear cell infiltration, atrophy, and metaplasia in the corpus and adjacent mucosa of the EGCs were determined and scored.

Results

The majority of EGCs (63/64) were located within the endoscopically assessed atrophic mucosa or along the atrophic border. The adjacent mucosa of the EGCs presented significantly higher degrees of all histological parameters than in the corpus (mononuclear cell infiltration, 0.86+/-0.09 vs. 0.51+/-0.11, P = 0.016; atrophy, 1.77+/-0.13 vs. 0.65+/-0.14, P<0.0001; metaplasia, 1.68+/-0.13 vs. 0.48+/-0.1, P<0.0001). The degree of endoscopic atrophy improved in the patients with longer post-H. pylori eradication periods; however, this trend was not observed for the histological parameters, and high degrees of atrophy and metaplasia were observed in the adjacent mucosa of the EGCs compared with the corpus during all periods (all P<0.05). The histological degrees of atrophy and metaplasia in the adjacent mucosa were particularly higher in the patients who underwent eradication due to gastric ulcers.

Conclusions

Severe gastric atrophy remained in the adjacent mucosa of the EGCs after H. pylori eradication, which may be linked to gastric carcinogenesis.

Histologic intestinal metaplasia and endoscopic atrophy are predictors of gastric cancer development after Helicobacter pylori eradication

BACKGROUND AND AIMS

Helicobacter pylori eradication therapy is effective at reducing the incidence of gastric cancer; however, gastric cancer still develops after eradication. We conducted a cohort study to elucidate the risk factors for gastric cancer development after successful H pylori eradication therapy.

METHODS

From June 1998 to December 2012 we assessed histologic and endoscopic findings of gastritis and performed H pylori eradication therapy in 748 patients without a history of gastric cancer. Patients were classified according to the distribution of intestinal metaplasia (IM) as follows: no IM (IM group A), IM in the antrum only (IM group B), and IM in the corpus (IM group C). We assessed atrophy endoscopically according to the Kimura-Takemoto classification system. Gastric cancer incidence was assessed.

RESULTS

A total of 573 patients underwent follow-up endoscopy; the mean duration of follow-up was 6.2 ± 4.8 years. Gastric cancer developed in 21 (20 intestinal type). The cumulative 5-year incidences of gastric cancer were 3.2% overall; 1.5%, 5.3%, and 9.8% in IM groups A, B, and C; and 0.7%, 1.9%, and 10% in the none/mild, moderate, and severe endoscopic atrophy groups, respectively. Compared with IM group A, the hazard ratio for IM group B was 3.6 (95% confidence interval [CI], 1.2-11), and that for IM group C was 3.7 (95% CI, 1.1-12). Compared with the none/mild endoscopic atrophy group, the hazard ratio for severe atrophy was 9.3 (95% CI, 1.7-174).

CONCLUSIONS

Patients with histologic IM or severe endoscopic atrophy were at increased risk of gastric cancer development after H pylori eradication.

Endoscopic gastric atrophy is strongly associated with gastric cancer development after Helicobacter pylori eradication

Background

Risk factors for gastric cancer during continuous infection with Helicobacter pylori have been well documented; however, little has been reported on the risk factors for primary gastric cancer after H. pylori eradication. We conducted a retrospective, endoscopy-based, long-term, large-cohort study to clarify the risk factors for gastric cancer following H. pylori eradication.

Methods

Patients who achieved successful H. pylori eradication and periodically underwent esophagogastroduodenoscopy surveillance thereafter at Toyoshima Endoscopy Clinic were enrolled. The primary endpoint was the development of gastric cancer. Statistical analysis was performed using the Kaplan–Meier method and Cox’s proportional hazards models.

Results

Gastric cancer developed in 15 of 1232 patients. The cumulative incidence rates were 1.0 % at 2 years, 2.6 % at 5 years, and 6.8 % at 10 years. Histology showed that all gastric cancers (17 lesions) in the 15 patients were of the intestinal type, within the mucosal layer, and <20 mm in diameter. Based on univariate analysis, older age and higher endoscopic grade of gastric atrophy were significantly associated with gastric cancer development after eradication of H. pylori, and gastric ulcers were marginally associated. Multivariate analysis identified higher grade of gastric atrophy (hazard ratio 1.77; 95 % confidence interval 1.12–2.78; P = 0.01) as the only independently associated parameter.

Conclusions

Endoscopic gastric atrophy is a major risk factor for gastric cancer development after H. pylori eradication. Further long-term studies are required to determine whether H. pylori eradication leads to regression of H. pylori-related gastritis and reduces the risk of gastric cancer.

Incidence of gastric cancer after endoscopic resection of gastric adenoma

BACKGROUND AND AIMS

The annual incidence of metachronous cancer after endoscopic resection (ER) of early gastric cancer (EGC) is approximately 3%. However, the incidence of gastric cancer after ER of a gastric adenoma is not known. The aim of this study was to determine whether the incidence of gastric cancer after ER of a gastric adenoma was different compared with that of metachronous cancer after ER of EGC.

METHODS

We retrospectively analyzed data from patients who underwent ER for gastric neoplasia from January 2005 to August 2013. Enrolled patients were divided into 2 groups: patients with low-grade dysplasia were included in the adenoma group and patients with high-grade dysplasia or invasive neoplasia were included in the EGC group. The main outcome was the incidence of gastric cancer after ER.

RESULTS

At a median follow-up of 28 months, gastric cancer newly developed in 13 adenoma patients (3.6%) and in 30 EGC patients (5.1%). The incidence rate of gastric cancer after ER was 14.4 cases per 1000 person-years in adenoma patients and 18.4 cases per 1000 person-years in EGC patients (P = .309 by the log-rank test). The hazard ratio of metachronous neoplasia in adenoma patients compared with EGC patients was 0.97 (95% confidence interval, 0.62-1.53). Metachronous tumors with invasion beyond the muscularis mucosa were more frequent in adenoma patients than in EGC patients (7/35 [20.0%] vs 3/63 [4.8%], P = .017).

CONCLUSION

The incidence of gastric cancer after ER for gastric adenoma was not significantly different from that of EGC. If further prospective studies confirm these findings, careful endoscopic surveillance with the same level of intensity should be considered for both gastric adenoma and EGC patients after ER.

Advanced Imaging Technology Other than Narrow Band Imaging

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.

Endoscopic surveillance of gastric cancers after Helicobacter pylori eradication

The incidence and mortality of gastric cancer remains high in East Asian countries. Current data suggest that Helicobacter pylori (H. pylori) eradication might be more effective for preventing gastric cancer in young people before they develop atrophic gastritis and intestinal metaplasia. However, the long-term effect of H. pylori eradication on metachronous cancer prevention after endoscopic resection (ER) of early gastric cancer remains controversial, with some discordance between results published for Japanese and Korean studies. The detection ability of synchronous lesions before ER and eradication of H. pylori directly influences these results. After eradication, some gastric cancers are more difficult to diagnose by endoscopy because of morphologic changes that lead to a flat or depressed appearance. Narrow-band imaging with magnifying endoscopy (NBI-ME) is expected to be useful for identifying metachronous cancers. However, some gastric cancers after eradication show a "gastritis-like" appearance under NBI-ME. The gastritis-like appearance correlates with the histological surface differentiation of the cancer tubules and superficial non-neoplastic epithelium atop or interspersed with the cancer. Till date, it remains unclear whether H. pylori eradication could prevent progression of gastric cancer. Until we can establish more useful endoscopic examination methodologies, regular endoscopic surveillance of high-risk groups is expected to be the most beneficial approach for detection.

Helicobacter pylori Eradication on the Prevention of Metachronous Lesions after Endoscopic Resection of Gastric Neoplasm: A Meta-Analysis

Background

There is controversy about the effect of Helicobacter pylori (H. pylori) eradication on the prevention of metachronous gastric cancer after endoscopic resection (ER).

Aims

The aim of this study was to systematically evaluate the effect of H. pylori eradication on the prevention of metachronous gastric lesions after ER of gastric neoplasms.

Methods

We performed a systematic search of PubMed, EMBASE, the Cochrane Library, and MEDLINE that encompassed studies through April 2014. Our meta-analysis consisted of 10 studies, which included 5881 patients who underwent ER of gastric neoplasms.

Results

When we compared the incidence of metachronous lesions between H. pylori-eradicated and non-eradicated groups, H. pylori eradication significantly lowered the risk of metachronous lesions after ER of gastric neoplasms (five studies, OR = 0.392, 95% CI 0.259 – 0.593, P < 0.001). When we compared H. pylori-eradicated and persistent groups, again, H. pylori eradication significantly lowered the incidence of metachronous lesions after ER of gastric neoplasms (six studies, OR = 0.468, 95% CI 0.326 – 0.673, P < 0.001). There was no obvious heterogeneity across the analyzed studies.

Conclusions

This meta-analysis suggests a preventive role for H. pylori eradication for metachronous gastric lesions after ER of gastric neoplasms. Thus, H. pylori eradication should be considered if H. pylori infection is confirmed during ER.

Safety and feasibility of simultaneous endoscopic submucosal dissection for multiple gastric neoplasias

BACKGROUND

Synchronous gastric neoplasms are not infrequently detected, thus endoscopic submucosal dissection (ESD) for multiple early gastric neoplasia is occasionally considered. However, there have been few investigations of the safety and feasibility of simultaneous ESD for multiple gastric lesions. This study aims to evaluate the safety and feasibility of simultaneous ESD for multiple gastric neoplasia.

METHODS

A total of 1823 patients who underwent ESD for 1929 gastric adenomas or early gastric cancers were retrospectively reviewed in this study. Two hundred gastric adenomas or early gastric cancers among 94 patients were treated by ESD simultaneously (multiple group), and 1729 patients were treated with ESD for a single lesion (single group).

RESULTS

En bloc resection (P = 0.060), complete resection (P = 0.362) and curative resection (P = 0.108) rates did not differ between the two groups. Rates of adverse events including bleeding (P = 0.317), perforation (P = 0.316) and aspiration pneumonia (P = 0.563) were not higher in the multiple group. Long-term follow-up showed more frequent local recurrence (P < 0.001), synchronous neoplasia (P = 0.041) and metachronous neoplasia (P < 0.001) per patient in the multiple group; however, local recurrence per lesion did not differ between the two groups (P = 0.103).

CONCLUSIONS

Simultaneous ESD for multiple synchronous gastric neoplasms is safe and feasible compared to single ESD. However, thorough examination for local recurrence and synchronous and metachronous neoplasia is required.

Low pepsinogen I level predicts multiple gastric epithelial neoplasias for endoscopic resection

Background/Aims

Synchronous/metachronous gastric epithelial neoplasias (GENs) in the remaining lesion can develop at sites other than the site of endoscopic resection. In the present study, we aimed to investigate the predictive value of serum pepsinogen for detecting multiple GENs in patients who underwent endoscopic resection.

Methods

In total, 228 patients with GEN who underwent endoscopic resection and blood collection for pepsinogen I and II determination were evaluated retrospectively.

Results

The mean period of endoscopic follow-up was 748.8±34.7 days. Synchronous GENs developed in 46 of 228 (20.1%) and metachronous GENs in 27 of 228 (10.6%) patients during the follow-up period. Multiple GENs were associated with the presence of pepsinogen I <30 ng/mL (p<0.001). Synchronous GENs were associated with the presence of pepsinogen I <30 ng/mL (p<0.001).

Conclusions

Low pepsinogen I levels predict multiple GENs after endoscopic resection, especially synchronous GENs. Cautious endoscopic examination prior to endoscopic resection to detect multiple GENs should be performed for these patients.

Surveillance using trimodal imaging endoscopy after endoscopic submucosal dissection for superficial gastric neoplasia

AIM: To evaluate the effectiveness of trimodal imaging endoscopy (TME) to detect another lesion after endoscopic submucosal dissection (ESD) for superficial gastric neoplasia (SGN).

METHODS: Surveillance esophagogastroduodenoscopy (EGD) using a TME was conducted in 182 patients that had undergone ESD for SGN. Autofluorescence imaging (AFI) was conducted after white-light imaging (WLI). When SGN was suspicious, magnifying endoscopy with narrow-band imaging (ME-NBI) was conducted. Final diagnoses were made by histopathologic findings of biopsy specimens. The detection rates of lesions in WLI, AFI, and NBI, and the characteristics of lesions detected by WLI and ones missed by WLI but detected by AFI were examined. The sensitivity, specificity, and accuracy of endoscopic diagnosis using WLI, AFI and ME-NBI were evaluated.

RESULTS: In 242 surveillance EGDs, 27 lesions were determined pathologically to be neoplasias. Sixteen early gastric cancers and 6 gastric adenomas could be detected by WLI. Sixteen lesions were reddish and 6 were whitish. Five gastric neoplasias were missed by WLI but were detected by AFI, and all were whitish and protruded gastric adenomas. There was a significant difference in color and pathology between the two groups (P = 0.006). Sensitivity, specificity and accuracy in ME-NBI were higher than those in both WLI and AFI. Specificity and accuracy in AFI were lower than those in WLI.

CONCLUSION: Surveillance using trimodal imaging endoscopy might be useful for detecting another lesion after endoscopic submucosal dissection for superficial gastric neoplasia.

Metachronous early gastric cancer over a period of 13 years after eradication of Helicobacter pylori

Stomach cancer can occur during chronic inflammation from Helicobacter pylori (HP) infection, and its occurrence can be suppressed by eradication of HP. However, the effects of suppressing stomach cancer by HP eradication are limited, and the cancer is known to recur even after eradication of this infection. Here, we report the case of a 56-year-old male patient with gastric cancer who, although undergoing HP eradication after treatment of early gastric cancer with endoscopy, experienced five metachronous cancer recurrences over a period of 13 years. Whether observation of patients who undergo eradication of HP due to peptic ulcers or chronic gastritis and patients who undergo eradication after endoscopic treatment for early gastric cancer should be performed at the same interval is an issue that must be addressed in the future. The appropriate observation period for each patient must be established while considering the burdens to the patient and from the medical economic perspective.

Metachronous gastric cancer after successful Helicobacter pylori eradication

The high incidence of gastric cancer in Japan initially resulted in establishment of a country-wide gastric cancer screening program to detect early and treatable cancers. In 2013 countrywide Helicobacter pylori (H. pylori) eradication was approved coupled with endoscopy to assess for the presence of chronic gastritis. Current data support the notion that cure of the infection in those with non-atrophic gastritis will prevent development of gastric cancer. However, while progression to more severe damage is halted in those who have already developed, atrophic gastritis/gastric atrophy remain at risk for subsequent development of gastric cancer. That risk is directly related to the extent and severity of atrophic gastritis. Methods to stratify cancer risk include those based on endoscopic assessment of the atrophic border, histologic grading, and non-invasive methods based on serologic testing of pepsinogen levels. Continued surveillance is required because those with atrophic gastritis/gastric atrophy retain considerable gastric cancer risk even after H. pylori eradication. Those who have already experienced a resectable early gastric cancer are among those at highest risk as metachronous lesions are frequent even after H. pylori eradication. We review the role of H. pylori and effect of H. pylori eradication indicating the incidence and the predictive factors on development of metachronous cancer after endoscopic therapy of early gastric cancer. Studies to refine risk markers to stratify for risk, surveillance methods, intervals, and duration after successful H. pylori eradication, and whether adjuvant therapy would change risk are needed.

CD44 variant 9 expression in primary early gastric cancer as a predictive marker for recurrence

BACKGROUND

Multiple early gastric cancers (EGCs) may develop in 6-14% of patients even after achieving curative endoscopic submucosal dissection (ESD); however, a useful biomarker for predicting recurrence is not available. The present study investigated whether the expression of CD44 variant 9 (CD44v9), a functional cancer stem cell marker, in the primary gastric cancer tissue represents an indicator of recurrence.

METHODS

Eighty-eight patients who underwent ESD for EGC from 2008 to 2010 were enrolled and monitored for recurrence for 3 years. The expression levels of CD44v9 in the tissue of initial EGCs were evaluated by immunohistochemistry, and the recurrence rate was compared between CD44v9-positive and CD44v9-negative groups. The mucin phenotype and expression of microRNA-21 (miR-21) and programmed cell death protein 4 (PDCD4) were also analysed.

RESULTS

The recurrence rate of EGC was significantly higher in the CD44v9-positive group than in the CD44v9-negative group (hazard ratio (HR), 21.8; 95% confidence interval (CI), 5.71-83.1). However, mucin phenotypes and the expression of miR-21 and PDCD4 did not predict recurrence after ESD. Meanwhile, grade of gastric atrophy was also identified as a significant marker of multiple recurrence (HR, 4.95; 95% CI, 1.30-18.8).

CONCLUSION

CD44 variant 9 expression represents a potential predictive marker for recurrence in EGC.

Screening and treating intermediate lesions to prevent gastric cancer

Early gastric cancer is defined as adenocarcinoma confined to the mucosa or submucosa irrespective of lymph node involvement. In Japan, mucosal high-grade neoplasia is diagnosed as intramucosal early gastric cancer. Some early gastric cancers progress to advanced gastric cancer after several years of follow-up. Image-enhanced endoscopy (chromoendoscopy), narrow-band imaging, and magnifying endoscopy increase the diagnostic yield in characterizing early gastric cancer. Endoscopic resection of intramucosal early gastric cancer with endoscopic mucosal resection or endoscopic submucosal dissection is currently performed in East Asian countries to prevent the development of advanced gastric cancer and preserve patients' quality of life after treatment.

Screening for precancerous lesions of upper gastrointestinal tract: from the endoscopists' viewpoint

Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.

Comprehensive investigation of areae gastricae pattern in gastric corpus using magnifying narrow band imaging endoscopy in patients with chronic atrophic fundic gastritis

BACKGROUND

Barium radiographic studies have suggested the importance of evaluating areae gastricae pattern for the diagnosis of gastritis. Significance of endoscopic appearance of areae gastricae in the diagnosis of chronic atrophic fundic gastritis (CAFG) was investigated by image-enhanced endoscopy.

MATERIALS AND METHODS

 Endoscopic images of the corpus lesser curvature were studied in 50 patients with CAFG. Extent of CAFG was evaluated with autofluorescence imaging endoscopy. The areae gastricae pattern was evaluated with 0.2% indigo carmine chromoendoscopy. Micro-mucosal structure was examined with magnifying chromoendoscopy and narrow band imaging.

RESULTS

 In patients with small extent of CAFG, polygonal areae gastricae separated by a narrow intervening part of areae gastricae was observed, whereas in patients with wide extent of CAFG, the size of the areae gastricae decreased and the width of the intervening part of areae gastricae increased (p < 0.001). Most areae gastricae showed a foveola-type micro-mucosal structure (82.7%), while intervening part of areae gastricae had a groove-type structure (98.0%, p < 0.001). Groove-type mucosa had a higher grade of atrophy (p < 0.001) and intestinal metaplasia (p < 0.001) compared with foveola type.

CONCLUSIONS

 As extent of CAFG widened, multifocal groove-type mucosa that had high-grade atrophy and intestinal metaplasia developed among areae gastricae and increased along the intervening part of areae gastricae. Our observations facilitate our understanding of the development and progression of CAFG.

Future candidates for indications of Helicobacter pylori eradication: do the indications need to be revised?

Since the discovery of Helicobacter pylori in 1982, the development of several treatment guidelines has allowed a consensus on the indications for H. pylori eradication. Beyond these currently accepted indications, including various upper gastrointestinal disorders and extragastric diseases, a significant amount of new information regarding H. pylori eradication is emerging. Certain types of acute gastritis, such as nodular gastritis, hypertrophic gastritis, Ménétrier's disease, hemorrhagic gastritis, and granulomatous gastritis are reversible after H. pylori eradication. Further, for chronic gastritis, closed-type atrophic gastritis and complete-type intestinal metaplasia appear to be more reversible after H. pylori eradication than open-type atrophic gastritis and incomplete-type intestinal metaplasia. Eradication can also be considered in subjects younger than 40 years who have a family history of gastric cancer and in subjects with long-term medications that might lead to bleeding (antiplatelet agents) or atrophy (proton pump inhibitors). Emerging evidence indicates that H. pylori eradication could be an effective treatment for some extragastric diseases that are unresponsive to conventional therapy. In such conditions, routine screening for eradication of H. pylori has not previously been recommended; a "test-and-treat" approach is suggested in the aforementioned situations. Given that H. pylori eradication is effective when the gastritis is reversible, future indications should be expanded to include acute gastric lesions that show marked improvement upon H. pylori eradication rather than just focusing on chronic gastric lesions. Future indications for H. pylori eradication should focus more on reversible lesions before preneoplastic conditions develop.

Gastric cancer: clinical aspects, epidemiology and molecular background

The validity and usefulness of the 7th edition of the UICC tumor node metastasis classification in the context of clinical management of gastric cancer are discussed. The most relevant new agent in gastric cancer therapy is trastuzumab for HER2-positive gastric carcinomas. This marks the success of continuous effort of translational research. Trastuzumab, initially applied in palliative settings, is currently being evaluated also in neoadjuvant treatment regimens. Several new meta-analyses support the carcinogenic effect of high salt intake and smoking in the context of Helicobacter pylori infection. Further data have become available on the efficacy of protective agents, acetyl salicylic acid/nonsteroidal anti-inflammatory drugs, and antioxidants. In search for a successful prevention strategy, the focus is on the identification of individuals at high risk who demand screening (testing) and surveillance. Serological assessment of gastric mucosal abnormalities with increased risk for gastric cancer development is extensively studied, and new data are presented from Asia as well as from Europe. New high-throughput techniques combined with bioinformatic vector analysis open the gate to the identification of new potential diagnostic and therapeutic targets. Furthermore, these approaches allow us to elucidate the interplay of bacterial virulence factors and the host's immune response as well as H. pylori-associated alterations of mucosal gene expression.