Clinical, Pathological and Endoscopic Features of Neoplastic or Non-neoplastic Reddish Depressed Lesions after Helicobacter pylori Eradication.

BACKGROUND AND AIMS: Early gastric cancers (EGCs) after Helicobacter pylori (H. pylori) eradication often appear as reddish depressed lesions (RDLs); the same features are also appeared in benign stomachs after eradication. We compared clinic-pathological and endoscopic features of benign and neoplastic RDLs after H. pylori eradication. METHODS: 228 neoplastic RDLs after H. pylori eradication were studied. All lesions were divided into neoplastic RDLs (differentiated carcinoma or adenoma, n=114) and benign RDLs (n=114) according to the histology. Clinical and pathological characteristics were compared in neoplastic and benign groups. Endoscopic diagnostic yields using the white light (WL) endoscopy, chromoendoscopy (CE) using indigo carmine dye and the magnifying endoscopy with narrow-band imaging (ME-NBI) were also evaluated in relation to the pathological diagnosis. RESULTS: Size of neoplastic RDLs was larger than that of benign RDLs (p<0.01). Sensitivity, specificity and accuracy for predicting pathological types of RDLs was 70.1%, 52.6% and 61.4% for the WL, 65.8%, 63.1% and 65.4% for the CE, while the ME-NBI scored better with the 88.6%, 88.6%, 99.1% and 93.9% of sensitivity, specificity and accuracy. The accuracy of the ME-NBI was 99.9% (113/114) in the benign RDLs and 89.4% (101/114) for the neoplastic RDLs. Undiagnosed neoplastic RDLs using the ME-NBI were associated with more differentiated tumors such as adenoma and well-differentiated adenocarcinoma (tub1) and the presence of an unclear demarcation line. CONCLUSIONS: ME-NBI is useful to diagnose RDLs after H. pylori eradiation, while some of neoplastic lesions are difficult to diagnose using the ME-NBI.

A case of chronic gastric anisakiasis coexisting with early gastric cancer.

Background: Anisakiasis is a parasitic disease caused by the consumption of raw or undercooked fish that is infected with Anisakis third-stage larvae. In countries, such as Japan, Italy, and Spain, where people have a custom of eating raw or marinated fish, anisakiasis is a common infection. Although anisakiasis has been reported in the gastrointestinal tract in several countries, reports of anisakiasis accompanied by cancer are rare. Case presentation: We present the rare case of a 40-year-old male patient with anisakiasis coexisting with mucosal gastric cancer. Submucosal gastric cancer was suspected on gastric endoscopy and endoscopic ultrasonography. After laparoscopic distal gastrectomy, granulomatous inflammation with Anisakis larvae in the submucosa was pathologically revealed beneath mucosal tubular adenocarcinoma. Histological and immunohistochemical investigation showed cancer cells as intestinal absorptive-type cells that did not produce mucin. Conclusion: Anisakis larvae could have invaded the cancer cells selectively because of the lack of mucin in the cancerous epithelium. Anisakiasis coexisting with cancer is considered reasonable rather than coincidental. In cancer with anisakiasis, preoperative diagnosis may be difficult because anisakiasis leads to morphological changes in the cancer.

Complete omission of second-look endoscopy after gastric endoscopic submucosal dissection in real-world practice.

Gastric endoscopic submucosal dissection (ESD) is increasingly performed in patients receiving antithrombotic therapy. Second-look endoscopy (SLE) has been performed empirically in several clinical settings. We investigated whether SLE omission was associated with an increased risk of postESD bleeding in all patients, including those administered antithrombotic agents. Between July 2016 and June 2018, 229 patients were treated with a clinical pathway for gastric ESD that involved SLE on the day after ESD (SLE group). Between September 2018 and May 2020, 215 patients were treated using a clinical pathway that did not include SLE (nonSLE group). We retrospectively compared the incidence of postESD bleeding among the propensity score-matched cohorts and determined the risk factors for postESD bleeding using multivariate analysis. The propensity score-matched cohorts showed no significant differences in the incidence of postESD bleeding between the SLE (3.2%) and nonSLE (5.1%) groups. Multivariate analysis revealed that the presence of lesions in the lower gastric body (adjusted odds ratio [OR] 2.17, 95% confidence interval [CI] 1.06-4.35, P.03) was a significant risk factor for postESD bleeding during admission, whereas resected specimen size ≥ 40 mm (adjusted OR 3.21, 95% CI 1.19-8.19, P.02) and antiplatelet therapy (adjusted OR 4.16, 95% CI 1.47-11.80, P.007) were significant risk factors after discharge. Complete omission of SLE after gastric ESD does not increase postESD bleeding in clinical practice.

H. pylori negative gastric MALT lymphoma with API2-MALT1 translocation treated by endoscopic submucosal dissection: A case report.

RATIONALE: API2-MALT1 positive gastric mucosa-associated lymphoid tissue (MALT) lymphomas are considered to have favorable prognosis. We report a case of API2-MALT1 positive gastric MALT lymphoma, treated by endoscopic submucosal dissection (ESD). PATIENT CONCERNS: A 51-year-old man underwent esophagogastroduodenoscopy (EGD) for the annual health checkup examination. DIAGNOSES: The EGD showed a reddish depressed lesion with small reddish spots in the lower gastric body. There was no endoscopic atrophy in the entire stomach and Helicobacter pylori (H. pylori) serum test was negative. Infiltration of small lymphocytes was shown in the gastric tissues obtained by the endoscopic biopsy. The fluorescence in situ hybridization using the biopsy samples confirmed the presence of genetic translocation of API2-MALT1, suggesting that the lesion is API2-MALT1 positive MALT lymphoma. INTERVENTIONS: Since endoscopic ultrasound suggested that the lesion was localized within the lamina propria mucosae, we performed ESD to achieve the en bloc resection of the lesion. OUTCOMES: Conclusive diagnosis of gastric MALT lymphoma was made based on the resected specimen. Lateral and vertical margins were negative. No lymphoma cells were detected using endoscopic biopsy after 5 years. LESSONS: Our report suggests that ESD can be considered as alternative treatment for API2-MALT1 positive gastric MALT lymphoma if the lesion was localized within the gastric mucosa.

Lower LINE-1 methylation is associated with promoter hypermethylation and distinct molecular features in gastric cancer.

Aim: To investigate the associations between LINE1 methylation, an indicator for genome-wide hypomethylation, molecular and clinicopathological characteristics of gastric cancer (GC) patients. Patients & methods:LINE1 methylation statuses were examined in paired cancerous, non-neoplastic mucosa from 217 GC and gastric mucosa from separate group of 224 noncancer patients. CpG island methylator phenotype, TP53 and KRAS mutation, MLH1 methylation status and promoter hypermethylation of GC related and H. pylori-related genes were examined. Results: Lower LINE1 methylation was observed in primary GC compared with non-neoplastic gastric mucosa and associated with CpG island methylator phenotype, TP53 mutation, MLH1 methylation and promoter hypermethylation of GC related and H. pylori-related genes. Conclusion: Lower LINE1 methylation correlates specific molecular subtypes and promoter hypermethylation in GC.

Diagnostic utility of probe-based confocal laser endomicroscopy in superficial non-ampullary duodenal epithelial tumors.

Background and study aims Endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADETs) has not been established. Probe-based confocal laser endomicroscopy (pCLE: Cellvizio) provides real-time endomicroscopic analysis. We developed and validated a new pCLE classification of SNADET based on abnormal findings. Patients and methods pCLE scanning of 20 SNADET lesions including 16 adenomas and four carcinomas was retrospectively evaluated to explore abnormal pCLE findings in relation to histological features. Diagnostic yield of pCLE findings was prospectively evaluated in an additional 20 SNADET lesions including 16 adenomas and four carcinomas. Results In a retrospective study, we identified four abnormal pCLE findings of SNADETs: (1) dark epithelium, (2) columnar cells irregularly extending to the lumen, (3) distorted crypt structure, and (4) fluorescein leakage. Dark epithelium distinguished neoplastic lesions (adenomas and carcinomas) from non-neoplastic duodenal mucosa with a sensitivity of 90 % and a specificity of 100 %. Distorted crypt structure distinguished carcinomas from adenomas and non-neoplastic duodenal mucosa with a sensitivity of 100% and a specificity of 94 %. In the prospective study, the sensitivity and the specificity of the dark epithelium for the diagnosis of neoplastic lesions (adenomas + carcinomas) was 75% and 100 %. Sensitivity and the specificity of the distorted crypt structure for discrimination of carcinoma from adenoma were 100 % and 94 %, respectively. Conclusions The pCLE findings correlated with the histopathology of the SNADETs. Dark epithelium and distorted crypt structure were informative pCLE findings to predict presence of neoplasia and cancer in the SNADET, respectively. UMIN-CTR UMIN000013857 TRIAL REGISTRATION: Single-Center, prospective observational trial UMIN000013857 at upload.umin.ac.jp.

Comparative study of magnifying narrow-band imaging and conventional white light endoscopy in the diagnosis of Helicobacter pylori status after eradication therapy.

Predicting Helicobacter pylori (Hp) status by endoscopic finding would be useful in recent clinical condition that the use of proton-pump inhibitors, anti-platelet, and anti-coagulant have become widespread. We aimed to elucidate the diagnostic accuracy of magnifying narrow-band imaging (M-NBI) endoscopy in distinguishing Hp status in patients with or without history of successful Hp eradication and compare this accuracy to the diagnostic accuracy of conventional white light (WL) endoscopy.Two hundred seven endoscopic examinations before and after Hp eradication were performed in prospective 163 patients. Endoscopic images by using the M-NBI and conventional WL were stored electronically and randomly allocated to 2 readers for evaluation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were assessed by reference to Hp status assessed by conventional clinical test.Sensitivity, specificity, PPV, NPV, and accuracy for predicting Hp status for the conventional WL was 72.2%, 75.5%, 72.2%, 75.5%, and 73.9% for the first reader; 86.6%, 57.3%, 64.1%, 82.9%, and 71.0% for the second reader. On the other hand, sensitivity, specificity, PPV, NPV, and accuracy for predicting Hp status for the M-NBI was 96.9%, 93.6%, 93.1%, 97.1%, and 95.2% for the first reader; 92.8%, 93.6%, 92.8%, 93.6%, and 93.2% for the second reader, respectively. The diagnostic accuracy of M-NBI was significantly higher than that of WL (P < .0001 for both readers). Inter-observer agreement of M-NBI (k = 0.83) was also better than that of WL (k = 0.53).M-NBI was capable of distinguishing Hp status before and after eradication therapy.

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.

Prostate Stem Cell Antigen Gene Polymorphism Is Associated with H. pylori-related Promoter DNA Methylation in Nonneoplastic Gastric Epithelium.

Genome-wide association study identified two functional SNPs associated with gastric cancer especially the diffuse type. The first was a polymorphism (rs2294008) in prostate stem cell antigen (PSCA), and the other was a polymorphism (rs4072037) in mucin 1 (MUC1). DNA methylation is associated with gastric cancer and Helicobacter pylori (H. pylori)-induced gastritis, while hypermethylation of promoter CpG island (CGI) is a common characteristic of enlarged-fold gastritis induced by H. pylori, a risk factor of diffuse-type gastric cancer. We evaluated the association between PSCA and MUC1 polymorphisms with H. pylori--related promoter CGI methylation in the nonneoplastic gastric mucosa. PSCA rs2294008 C/T and MUC1 rs4072037 A/G polymorphisms were genotyped in 410 cancer-free subjects in relation to promoter CGI methylation status of three candidate genes, of which the methylation status is associated with H. pylori infection (IGF2, MYOD1, and SLC16A12). Methylation levels of all three genes were significantly higher in subjects with PSCA rs2294008 T/T compared with the PSCA rs2294008 C/C (all P < 0.05). Such associations were more enhanced in H. pylori-positive subjects (all P < 0.01). The multivariate analysis demonstrated that PSCA C/T [OR, 2.37; 95% CI (confidence interval), 1.06-5.29; P = 0.035] and T/T genotypes (OR, 3.2; 95% CI, 1.41-7.25; P = 0.005) were significantly associated with methylation-high gastric mucosa as independent factors. MUC1 rs4072037 A/G polymorphism was not associated with methylation status of all three genes. PSCA C/T and T/T genotypes are associated with H. pylori-related promoter DNA methylation in the gastric mucosa.Impact: Our observations provided the evidence that PSCA polymorphism influence the susceptibility to gastric cancer through DNA methylation induction.

Molecular subtyping of gastric cancer combining genetic and epigenetic anomalies provides distinct clinicopathological features and prognostic impacts.

Both genetic and epigenetic abnormalities play important roles in gastric cancer (GC) development. We investigated whether the molecular subtypes of gastric cancer by combining genetic and epigenetic anomalies define its clinicopathological features and prognosis. The CpG island methylator phenotype (CIMP), MLH1 methylation, TP53, and KRAS mutation statuses were characterized in 214 GCs in relation to their clinicopathological features and prognosis. The molecular subtypes based on CIMP and TP53 hot spot mutation status (R175, G245, R248, R273, and R282) best predicted prognosis of GC. These subtypes contained 120 CIMP-positive (CIMP+) TP53 hot spot mutation-negative (TP53 hot spot-) cases, 81 CIMP-negative (CIMP-) TP53 hot spot- cases, 8 CIMP+TP53 hot spot mutation-positive (TP53 hot spot+) cases, and 5 CIMP- TP53 hot spot+ cases. The CIMP-TP53 hot spot+ group presented the worst overall survival (OS) and progression-free survival (PFS), followed by the CIMP+TP53 hot spot+, CIMP-TP53 hot spot- and CIMP+TP53 hot spot- groups (both P < 0.0001). These subtypes also correlated well with several aggressive clinicopathological features in that order. The molecular subtypes were independent factors for predicting overall survival (hazard ratio = 1.66, 95% CI = 1.07-2.57, P = 0.006). The molecular subtypes combining the CIMP and TP53 hot spot mutation status provide distinct clinicopathological features and prognostic impacts in GC.

DNA methylation accumulation in gastric mucosa adjacent to cancer after Helicobacter pylori eradication.

Molecular irreversibleness with Helicobacter pylori (H. pylori) infection might have a role in gastric tumorigenesis after H. pylori eradication. We performed comprehensive DNA methylation profiling of gastric mucosa after H. pylori eradication with or without gastric cancer. Using four different groups of biopsies obtained from gastric body without history of H. pylori infection (Hp-), gastric body without cancer after H. pylori eradication (cancer-free body), gastric body with early gastric cancer diagnosed after H. pylori eradication (EGC body) and their paired samples from adjacent mucosa of cancer (EGC ADJ), methylation status of five candidate genes (MYOD1, SLC16A12, IGF2, RORA and PRDM5) was examined by the bisulfite pyrosequencing. An Infinium Methylation EPIC BeadChip array was also used to characterize the methylation status of greater than 850,000 CpG sites. The EGC ADJ group showed highest methylation levels of five candidate genes among the four groups of biopsies. In the gastric body (cancer-free body + EGC body), methylation levels were significantly decreased in patients with longer period after eradication, while such association was not observed in EGC ADJ group. Hyper methylated samples were associated with shorter telomere, an indicator for rapid cell turnover, and higher DNMT1 protein expression, an enzyme related to methyl transfer reaction. The genome-wide methylation analysis demonstrated strikingly higher methylation levels especially at CpG islands in the EGC ADJ group. Exclusively hypermethylated promoter CpG islands in the same group frequently coded zinc finger proteins. Our data show that DNA methylation accumulation is associated with molecular irreversibleness and gastric carcinogenesis after H. pylori eradication.

Unusual growth of an Epstein-Barr virus-associated differentiated early-stage gastric carcinoma: A case report.

Epstein-Barr virus (EBV) infection is involved in a subset of gastric carcinoma (GC) cases, and is associated with distinct clinicopathological features. The present study reports a unique case of EBV-associated early-stage GC compared with the other cases experienced in our hospital. A 72-year-old male receiving treatment for cerebral infarction underwent an esophagogastroduodenoscopy (EGD) for suspicion of gastrointestinal bleeding. EGD revealed a type 0-I protruding lesion in the lesser curvature of the upper gastric corpus. Biopsy indicated well-differentiated adenocarcinoma. As the tumor diameter was >3 cm and the thickness of the tumor suggested submucosal invasion, laparoscopic gastrectomy was performed. Histological assessment revealed polypoid growth of an intramucosal, differentiated, tubular or papillary adenocarcinoma, with dense infiltration of lymphocytes. The carcinoma crypts were found to be EBV-positive on in situ hybridization. A review of the clinicopathological features of 25 EBV-associated GCs from 20 patients treated in our hospital between 2005 and 2014 was performed. All of these tumors, except that in the current case, appeared as shallow, depressed or ulcerative lesions. Thus, the current case appears to represent an unusual growth of EBV-positive GC.

Telomere length in the gastric mucosa after Helicobacter pylori eradication and its potential role in the gastric carcinogenesis.

The molecular mechanisms of gastric carcinogenesis after Helicobacter pylori (H. pylori) eradication remain unclear. We examined the telomere length of gastric mucosa samples after successful H. pylori eradication in patients without and those with gastric cancer. Telomere length was measured by the real-time PCR among four different groups of biopsies: gastric body from subjects without history of H. pylori infection (Hp-: n = 23), gastric body from cancer-free subjects after H. pylori eradication (cancer-free body: n = 24), gastric body from early gastric cancer patients diagnosed after H. pylori eradication (EGC body: n = 35) and its paired samples from adjacent mucosa of cancerous area (EGC ADJ: n = 35). The Hp-group presented the longest telomeres among the all groups (Hp- vs. all others, all P < 0.05). Samples from EGC body group showed shorter telomere length than the samples from cancer-free body groups (P < 0.05). Conversely, samples from EGC ADJ group showed rather longer telomere length compared to the EGC body group (P < 0.05), which was also confirmed by the comparison of 35 matched samples (P = 0.0007). Among the samples after H. pylori eradication, shorter telomere length was associated with higher expression of IL-1B and NF-kB (P < 0.0001, 0.0006, respectively). Longer telomere length was also associated with higher expression of TNF-A (P = 0.01). Telomere shortening seems to be important initial steps in gastric cancer predisposition after H. pylori eradication, while it might shift to lengthening to acquire more aggressive pathway to develop cancer.

Methylation status of IGF2 DMR and LINE1 in leukocyte DNA provides distinct clinicopathological features of gastric cancer patients.

DNA methylation of leukocyte DNA has been proposed to be a biomarker for cancer that can be used to target patients for appropriate clinical implementation. We investigated IGF2 DMR and LINE1 methylation in the leukocyte DNA and their association with clinicopathological features and prognosis of gastric cancer (GC) patients. Methylation status of IGF2 DMR and LINE1 in the leukocyte DNA was quantified using bisulfite pyrosequencing in 207 GC patients. Methylation of both IGF2 DMR and the LINE1 was significantly higher in the undifferentiated histologic type compared to the differentiated histologic type (both P = 0.0002). Hypermethylation of both the IGF2 DMR and the LINE1 was associated with more aggressive features of GC such as advanced stage (IGF2 DMR, P = 0.0002; LINE1, P < 0.0001), lymphatic invasion positive (IGF2 DMR, P = 0.004; LINE1, P = 0.002), venous invasion positive (IGF2 DMR, LINE1, both P = 0.03), lymph node metastasis positive (IGF2 DMR, P = 0.01; LINE1, P = 0.001), peritoneal dissemination positive (IGF2 DMR, P = 0.04; LINE1, P = 0.002), liver metastasis positive (IGF2 DMR, P = 0.008; LINE1, P = 0.001), and other distant metastasis positive (IGF2 DMR, P = 0.04). Our data suggest that high LINE1 and IGF2 DMR methylation status would be a phenomenon that is observed with the progression of GC, supporting their potential utility as a biomarker in GC patients.

In vivo diagnosis of early-stage gastric cancer found after Helicobacter pylori eradication using probe-based confocal laser endomicroscopy.

BACKGROUND AND AIM: Early-stage gastric cancer (EGC) found after Helicobacter pylori (Hp) eradication often displays non-tumorous regenerative epithelium and/or maturated tumorous epithelium overlying the cancerous tissue, which may confuse endoscopic and histological diagnosis. Probe-based confocal laser endomicroscopy (pCLE) enables in vivo real-time optical biopsy. We compared the diagnostic yields for these EGC cases using conventional white light endoscopy (WL), magnifying endoscopy with narrow-band imaging (ME-NBI), pCLE, and endoscopic biopsy; we also compared the accuracy of the horizontal extent diagnosis between ME-NBI and pCLE. METHODS: This study enrolled 30 patients with 36 EGC lesions after successful Hp eradication. Diagnostic yields of WL, ME-NBI, pCLE, and endoscopic biopsy were prospectively compared. Four points of cancerous margins (oral, anal, anterior, and posterior sites) were also prospectively evaluated with M-NBI and pCLE to determine the horizontal extent of the EGC. RESULTS: Diagnostic yield was significantly higher with pCLE than with WL and endoscopic biopsy (97 vs 72%, 97 vs 72%, P = 0.0159, 0.0077, respectively), whereas it did not differ from ME-NBI (88.9%, P = 0.371). Height of non-tumorous regenerative epithelium or maturated atypical glands was 104.7 ± 34.2 µm in the pCLE-positive cases, whereas it was 188.3 ± 27.1 µm in a pCLE-negative case (P = 0.0004). Diagnostic accuracy of the horizontal margin of EGC was significantly higher with pCLE than with ME-NBI (92 vs 70%, P = 0.0159). CONCLUSION: pCLE may be helpful for the diagnosis of ambiguous ECG found after Hp eradication because it enables real-time scanning throughout the lesion and detection of subsurface microstructure.

A Comparative Study of White Light Endoscopy, Chromoendoscopy and Magnifying Endoscopy with Narrow Band Imaging in the Diagnosis of Early Gastric Cancer after Helicobacter pylori Eradication.

BACKGROUND AND AIM: Early-stage gastric cancer (EGC) found after H. pylori eradication often has non-tumorous epithelium on the tumorous tissue and/or surface differentiation of tumors, which may confuse endoscopic and histologic diagnosis. We investigated the diagnostic reliability of EGC using conventional white light endoscopy (WLE), chromoendoscopy (CE) using indigo carmine, and magnifying endoscopy with narrow band imaging (ME-NBI) in patients with EGC with or without history of prior H. pylori eradication therapy. METHODS: Diagnostic reliability of EGC by using the WLE, CE and ME-NBI was investigated in 71 EGC lesions diagnosed after successful H. pylori eradication (eradication group) and 115 EGC lesions with current H. pylori infection (control group). RESULTS: Diagnostic reliability of EGC was lower in the eradication group than in the control group using all three modalities. In particular, the diagnostic accuracy of CE in the eradication group was especially lower compared to that of the control group (WLE: 74.6% vs. 86.1%, P=0.05; CE: 64.8% vs. 91.3%, P<0.0001; ME-NBI: 88.7% vs. 98.2%, P=0.01). The ME-NBI scored better in comparison with WLE and CE in the eradication group (both P<0.05). The indistinct EGC lesions in the eradicated group by using CE were associated with the presence of histological changes such as non-tumorous epithelium on the tumor and/or surface differentiation of tumors (P=0.005). CONCLUSIONS: It should be noted that the diagnostic reliability of EGC after H. pylori eradication becomes lower especially using CE. Indistinguishable cases using CE are associated with histological findings such as non-tumorous epithelium on the tumor and/or surface differentiation of tumors.

Potential link between Fusobacterium enrichment and DNA methylation accumulation in the inflammatory colonic mucosa in ulcerative colitis.

BACKGROUND AND AIM: Fusobacterium enrichment has been associated with colorectal cancer development. Ulcerative colitis (UC) associated tumorigenesis is characterized as high degree of methylation accumulation through continuous colonic inflammation. The aim of this study was to investigate a potential link between Fusobacterium enrichment and DNA methylation accumulation in the inflammatory colonic mucosa in UC. METHODS: In the candidate analysis, inflamed colonic mucosa from 86 UC patients were characterized the methylation status of colorectal a panel of cancer related 24 genes. In the genome-wide analysis, an Infinium HumanMethylation450 BeadChip array was utilized to characterize the methylation status of >450,000 CpG sites for fourteen UC patients. Results were correlated with Fusobacterium status. RESULTS: UC with Fusobacterium enrichment (FB-high) was characterized as high degree of type C (for cancer-specific) methylation compared to other (FB-low/neg) samples (P<0.01). Genes hypermethylated in FB-high samples included well-known type C genes in colorectal cancer, such as MINT2 and 31, P16 and NEUROG1. Multivariate analysis demonstrated that the FB high status held an increased likelihood for methylation high as an independent factor (odds ratio: 16.18, 95% confidence interval: 1.94-135.2, P=0.01). Genome-wide methylation analysis demonstrated a unique methylome signature of FB-high cases irrespective of promoter, outside promoter, CpG and non-CpG sites. Group of promoter CpG sites that were exclusively hypermethylated in FB-high cases significantly codified the genes related to the catalytic activity (P=0.039). CONCLUSION: Our findings suggest that Fusobacterium accelerates DNA methylation in specific groups of genes in the inflammatory colonic mucosa in UC.

Endoscopic features of lymphoid follicles using blue laser imaging (BLI) endoscopy in the colorectum and its association with chronic bowel symptoms.

BACKGROUND/AIM: In the colorectum, lymphoid follicles hyperplasia (LH) is sometimes observed as small, round, yellowish-white nodules. The novel image-enhanced endoscopy system named blue laser imaging (BLI) provides enhanced the contrast of surface vessels using lasers for light illumination. We investigated the endoscopic features of LH observed by using BLI endoscopy and its association with chronic bowel symptoms. PATIENTS/METHODS: 300 participants undergoing colonoscopy for various indications were enrolled. Entire colorectum was observed by using BLI-bright mode with non-magnification view. LH was defined as well demarcated white nodules. Elevated LH with erythema was distinguished as LH severe. RESULTS: LHs were observed more clearly by using BLI-bright mode compared to conventional white light colonoscopy and were also histologically confirmed as intense infiltration of lymphocytes or plasmacytes. LH was observed in 134 subjects (44.6%) and 67 (22.3%) were LH severe. LH was associated younger age (Odds ratio (OR) = 1.05, 95%Confidence Interval (95%CI) = 1.03-1.07, P<0.0001) and chronic bowel symptoms including constipation, hard stools, diarrhea and loose stools (all LH: OR = 4.03, 95%CI = 2.36-6.89, P<0.0001, LH severe: OR = 5.31, 95%CI = 2.64-10.71, P<0.0001). LH severe was closely associated with both constipation associated symptoms (OR = 3.94, 95%CI = 1.79-8.66, P = 0.0007) and diarrhea associated symptoms (OR = 5.22, 95%CI = 2.09-13.05, P = 0.0004). In particular, LH severe in the ascending colon was strongly associated with bowel symptoms (P<0.0001). CONCLUSION: LH, visualized by using BLI endoscopy was associated with bowel symptom, raising the possibility of pathogenic role of this endoscopic finding in the functional lower gastrointestinal disorders.

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.

Magnifying narrow-band imaging of gastric mucosal morphology predicts the H. pylori-related epigenetic field defect.

DNA methylation is associated with "field defect" in the gastric mucosa. To characterize "field defect" morphologically, we examined DNA methylation of non-neoplastic gastric mucosa in relation to their morphology seen by narrow-band imaging (NBI) with magnifying endoscopy. Magnifying NBI of non-neoplastic gastric body was classified as follows: normal-small and round pits with uniform subepithelial capillary networks; type 1-a little enlarged round pits with indistinct subepithelial capillary networks; type 2-remarkably enlarged pits with irregular vessels; and type 3-clearly demarcated oval or tubulovillous pits with bulky coiled or wavy vessels. Methylation of nine candidate genes (MYOD1, SLC16A12, GDNF, IGF2, MIR 124A1, CDH1, PRDM5, RORA and MLF1) were determined by bisulfite pyrosequencing. Infinium HumanMethylation450 array was used to characterize the methylation of >450,000 CpG sites. Mean Z score methylation of nine genes positively correlated with the changes of mucosal patterns from normal to types 1, 2, and 3 (P < 0.0001). Genome-wide analysis showed that development of mucosal patterns correlated with methylation accumulation especially at CpG islands. Genes with promoter CpG islands that were gradually methylated with the development of mucosal patterns significantly enriched the genes involved in zinc-related pathways. The results indicates that gastric mucosal morphology predicts a "field defect" in this tissue type. Accumulation of DNA methylation is associated with "field defect" in the non-neoplastic gastric mucosa. Endoscopic identification of "field defect" has important implications for preventing gastric cancer. Our results suggest that magnifying NBI of gastric mucosal morphology predicts a "field defect" in the gastric mucosa.