Helicobacter pylori infection associated DNA methylation in primary gastric cancer significantly correlates with specific molecular and clinicopathological features.

Helicobacter pylori induces DNA methylation in gastric mucosa, which links to gastric cancer (GC) risk. In contrast, CpG island methylator phenotype (CIMP) is defined as high levels of cancer-specific methylation and provides distinct molecular and clinicopathological features of GC. The association between those two types of methylation in GC remains unclear. We examined DNA methylation of well-validated H. pylori infection associated genes in GC and its adjacent mucosa and investigated its association with CIMP, various molecular subtypes and clinical features. We studied 50 candidate loci in 24 gastric samples to identify H. pylori infection associated genes. Identified loci were further examined in 624 gastric tissue from 217 primary GC, 217 adjacent mucosa, and 190 mucosae from cancer-free subjects. We identified five genes (IGF2, SLC16A2, SOX11, P2RX7, and MYOD1) as hypermethylated in H. pylori infected gastric mucosa. In non-neoplastic mucosa, methylation of H. pylori infection associated genes was higher in patients with GC than those without. In primary GC tissues, higher methylation of H. pylori infection associated genes correlated with CIMP-positive and its related features, such as MLH1 methylated cases. On the other hand, GC with lower methylation of these genes presented aggressive clinicopathological features including undifferentiated histopathology, advanced stage at diagnosis. H. pylori infection associated DNA methylation is correlated with CIMP, specific molecular and clinicopathological features in GC, supporting its utility as promising biomarker in this tumor type.

Comprehensive DNA methylation profiling of Barrett's esophagus and esophageal adenocarcinoma in Japanese patients.

Molecular mechanisms of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remain unclear in Japanese patients. Japanese EACs frequently have underlying short length BE: short-segment BE (SSBE), for which, neoplastic potential remains unclear. We performed comprehensive methylation profiling of EAC and BE in Japanese patients, mostly comprised with SSBE. Using three different groups of biopsies obtained from non-neoplastic BE from patients without cancer (n = 50; N group), with EAC (n = 27; ADJ group) and EAC (n = 22; T group), methylation statuses of nine candidate genes (N33, DPYS, SLC16A12, CDH13, IGF2, MLF1, MYOD1, PRDM5, and P2RX7) were examined by the bisulfite pyrosequencing. Reduced representation bisulfite sequencing was performed to characterize the genome-wide methylation status in 32 samples (12 from N, 12 ADJ, and 8 from T groups). In the candidate approach, methylation levels of N33, DPYS, and SLC16A12 were higher in ADJ and T groups compared to that in N group. The ADJ group was an independent factor for higher DNA methylation in non-neoplastic BE. The genome-wide approach demonstrated an increase of hypermethylation from ADJ to T groups relative to N group near the transcription start sites. Among gene groups hypermethylated in ADJ and T groups (n = 645) and T group alone (n = 1438), 1/4 and 1/3 were overlapped with downregulated genes in the microarray data set, respectively. Accelerated DNA methylation is observed in EAC and underlying BE in Japanese patients, mostly comprised with SSBE, highlighting the potential impact of methylation in early carcinogenesis.

Changes in intestinal bacteria and imbalances of metabolites induced in the intestines of pancreatic ductal adenocarcinoma patients in a Japanese population: a preliminary result.

BACKGROUND: The relationship between pancreatic ductal adenocarcinoma (PDAC) and the intestinal environment is not fully understood. The purpose of this study was to elucidate the characteristics of the intestinal environment in PDAC. METHODS: We performed a case-control study of 5 Japanese patients with unresectable PDAC located in the body or tail (PDAC-bt). The number of patients analyzed was limited for this preliminary study. We included 68 healthy subjects, herein control, of pre-printed study in the preliminary study. 16S rRNA amplicon sequencing and metabolomic analysis were performed using fecal samples from the subjects. RESULTS: There was no difference in the Shannon index and Principal Coordinate Analysis between PDAC-bt and the control. However, a significant increase in oral-associated bacteria (Actinomyces, Streptococcus, Veillonella, Lactobacillus) was observed. A significant decrease of Anaerostipes was demonstrated in the feces of PDAC-bt compared with the control. The intestinal propionic acid and deoxycholic acid were significantly lower in PDAC-bt compared with the control. CONCLUSIONS: We showed that the intestinal environment of PDAC-bt is characterized by an increase in oral-associated bacteria and an imbalance of metabolites but without changes in alpha and beta diversity of the gut microbiota profiles.Clinical Trial Registration: www.umin.ac.jp, UMIN 000041974, 000023675, 000023970.

Injury to the muscle layer, increasing the risk of post-colorectal endoscopic submucosal dissection electrocoagulation syndrome.

BACKGROUND AND AIM: In colorectal endoscopic submucosal dissection (ESD), post-ESD electrocoagulation syndrome (PECS) has been recognized as one of the major complications. There are no reports on the relationships between ESD findings and PECS. This study aims to evaluate the risk factors for PECS, including ESD findings such as muscularis propria exposure. METHODS: We performed a retrospective cohort study of patients who underwent colorectal ESD between January 2017 and December 2021 in Japan. The grade of injury to the muscle layer caused by ESD was categorized as follows: Grade 0, no exposure of muscularis propria; Grade 1, muscularis propria exposure; Grade 2, torn muscularis propria; and Grade 3, colon perforation. The risk factors for PECS, including injury to the muscle layer, were analyzed by univariate and multivariate analyses. RESULTS: Out of 314 patients who underwent colorectal ESD, PECS occurred in 28 patients (8.9%). The multivariate analysis showed that female sex (odds ratio [OR] 3.233; 95% confidence interval [95% CI]: 1.264-8.265, P = 0.014), large specimen size (≥ 40 mm) (OR 6.138; 95% CI: 1.317-28.596, P = 0.021), long procedure time (≥ 90 min) (OR 2.664; 95% CI: 1.053-6.742, P = 0.039), and Grade 1 or 2 injury to the muscle layer (OR 3.850; 95% CI: 1.090-13.61, P = 0.036) were independent risk factors for PECS. CONCLUSIONS: Injury to the muscle layer, such as exposure or tear, was identified as a novel independent risk factor for PECS. We should perform colorectal ESD carefully to avoid injuring the muscle layers.

Scoring system for predicting the prognosis of elderly gastric cancer patients after endoscopic submucosal dissection.

OBJECTIVES: Comprehensive assessments of the long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in the elderly are unavailable. We aimed to create a scoring system to predict the long-term prognosis after ESD for EGC among patients aged ≥75 years. METHODS: We conducted retrospective studies of two cohorts: a single-center cohort (2006-2011) for developing the scoring system, and a multicenter cohort for validating the developed system (2012-2016). In the development cohort, factors related to death after ESD were identified using multivariable Cox regression analysis, and a predictive scoring system was developed. In the validation cohort, the scoring system was validated in 295 patients. RESULTS: In the development cohort, Charlson comorbidity index (CCI) ≥3 (hazard ratio [HR] 3.017), high psoas muscle index (PMI) (HR 2.206), and age ≥80 years (HR 1.978) were significantly related to overall survival after ESD. Therefore, high CCI, low PMI, and age ≥80 years were assigned 1 point each. The patients were categorized into low (≤1 point) and high (≥2 points) score groups based on their total scores. In the validation cohort, 184 and 111 patients were assigned to the low- and high-score groups, respectively. In comparisons based on Kaplan-Meier curves, the 5-year survival rate was 91.5% in the low-score group and 57.8% in the high-score group (log-rank test; P < 0.001). CONCLUSION: Our scoring system including high CCI, low PMI, and age ≥80 years could stratify the long-term prognosis of elderly patients aged ≥75 years after ESD for EGC.

Novel image enhancement technology that helps find bleeding points during endoscopic submucosal dissection of gastric neoplasms.

BACKGROUND AND AIM: The management of bleeding during endoscopic submucosal dissection (ESD) is critical and related to the procedure time. We collaborated on a new image enhancement algorithm with parameter optimization for clinical use being developed by FUJIFILM Co. and processed white light image data offline to evaluate the effectiveness of this technology. This study aims to evaluate the clinical usefulness of this technology. METHODS: Eighteen video scenes of bleeding points from five gastric ESDs were selected and processed by the new image enhancement algorithm. The time until a bleeding point was found, visibility of a bleeding point, and color abnormality of the submucosal layer were evaluated by ESD experts, ESD trainees, and endoscopy trainees. The color differences between the bleeding point and the surroundings in CIE-L*a*b* color space were calculated in the original and enhanced images. RESULTS: The time until a bleeding point was found in the enhanced videos was significantly shorter than that in the original videos (11.10 s vs 13.85 s) (P = 0.017). On a 5-point (-2 to +2) Likert scale of visibility, the enhanced image was slightly superior to the original (+0.45), and the appearance of the submucosa was comparable between images (+0.14). The color difference among the bleeding areas on the enhanced images was significantly larger than that on the original images (10.93 vs 8.36). CONCLUSION: This novel image enhancement algorithm emphasizes the color difference between a bleeding point and the surrounding area, which would help find bleeding points faster during ESD for the less experienced endoscopists.

Effect of DNMT3A polymorphisms on CpG island hypermethylation in gastric mucosa.

BACKGROUND: CpG methylation of tumor suppressor genes occurs in the early stage of carcinogenesis. Detecting risk factors for aberrant CpG methylation is clinically important for predicting cancer development. DNA methyltransferase (DNMT) 3a is considered to play critical roles in the DNA methylation process during pathogenesis. In this study, we evaluated the association between DNMT3A polymorphisms (rs6733868 and rs13428812) and CpG methylation status in non-cancerous gastric mucosa. METHODS: We determined the DNMT3A genotype and CpG methylation status of 4 genes (p14ARF, p16INK4a, DAPK, and CDH1) in 510 subjects without gastric cancer. Helicobacter pylori (HP) infection status was determined by the rapid urease test, urea breath test, speculum examination, or serum antibody test. We determined the DNMT3A genotype using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP). CpG methylation status was determined by methylation-specific polymerase chain reaction (MSP). When the methylated band was stronger than 10 ng/µL according to the DNA marker, we judged CpG island hypermethylation (CIHM) to be present. Associations between genotypes and susceptibilities were assessed by logistic regression analysis. RESULTS: The minor allele frequencies of both polymorphisms (rs6733868 and rs13428812) were lower in the CpG methylated groups of each of the 4 genes (p14ARF, p16INK4a, DAPK, and CDH1). Using a dominant genetic model, rs6733868 was significantly associated with the hypermethylation of each gene, whereas rs13428812 was associated with the methylation of 3 genes (all except p14ARF). When low-CIHM was defined as 1 or 2 CpG islands methylated and high-CIHM was defined as 3 or more CpG islands methylated, carrying the minor allele of rs6733868 was associated with both decreased low- and high-CIHM, and that of rs13428812 also was associated with a decrease. Comparing low-CIHM with high-CIHM, carrying the minor alleles of rs6733868 or rs13428812 was related to decreased susceptibility to high-CIHM. In HP-infected subjects, carrying the minor alleles of rs6733868 or rs13428812 had a significantly greater association with decreased susceptibility to high-CIHM. CONCLUSIONS: Our study indicates that polymorphisms of DNMT3A are associated with the accumulation of gene methylation in gastric mucosa. Carrying the minor alleles of rs6733868 or rs13428812 inhibits aberrant gene methylations, which are typically enhanced by HP infection.

Influence of MIF polymorphisms on CpG island hyper-methylation of CDKN2A in the patients with ulcerative colitis.

BACKGROUND: CDKN2A hypermethylation is among the major events associated with carcinogenesis and is also observed in non-neoplastic colonic mucosa in patients with ulcerative colitis (UC). Macrophage migration inhibitory factor (MIF) plays a crucial role in promoting gastrointestinal inflammation characteristic of UC. The aim of this study is to explore associations between CDKN2A methylation status and MIF polymorphisms (rs755622 and rs5844572). METHODS: One hundred and fifty-nine patients diagnosed with UC were enrolled in this study. The methylation status of p14ARF and p16INK4a was determined by MSP; MIF genotypes were identified by PCR-SSCP. RESULTS: We found no differences with respect to mean age, gender, clinical type (chronic continuous or relapse/remitting), or extent of disease among the patients with methylated and unmethylated p14ARF or p16INK4a. Carrying the rs755622 C allele indicated a significantly higher risk for p14ARF methylation (odds ratio (OR), 2.16; 95% confidence interval (CI), 1.08-4.32; p = 0.030); similarly, carrying the rs5844572 7-repeat allele indicated a significantly higher risk for p16INK4a methylation (OR, 2.57; 95% CI, 1.26-5.24; p = 0.0094) after an adjusted regression analysis. The carriers of the rs755662 C allele or the rs5844572 7-repeat allele were both at a significantly higher risk for methylation of both p14ARF and p16INK4a when compared to the cohort in which neither of the genes were methylated (OR, 2.70; 95% CI, 1.22-6.01; p = 0.015 and OR, 2.87; 95% CI, 1.25-6.62; p = 0.013, respectively). Additionally, carrying rs755622 C allele was significantly associated with CIHM in chronic continuous of clinical type and total colitis (OR, 25.9; 95% CI, 2.55-262.6; p = 0.0059 and OR, 4.38; 95% CI, 1.12-17.2; p = 0.034, respectively), and carrying 7-repeat allele of rs5844572 was significantly associated in chronic continuous type (OR, 14.5; 95%CI, 1.46-144.3; p = 0.022). CONCLUSIONS: Taken together, our findings suggest that MIF genotypes associated with inflammation may also be involved in promoting carcinogenesis via CDKN2A hypermethylation in patients diagnosed with UC.

Usefulness of Full-spectrum Endoscopy for the Upper Gastrointestinal Tract.

GOALS: We determined whether full-spectrum endoscopy (FUSE) improved the visualization rates of blind spots in a single-center case control study. BACKGROUND: FUSE provides a 210-degree angle of view with a left side-viewing camera in addition to a forward-viewing camera. FUSE can improve the detectability of blind spots in conventional forward-viewing esophagogastroduodenoscopy (EGD), such as the major duodenal papilla (MDP) and the anal side of the pyloric ring. STUDY: Between April 2016 and May 2017, successful visualization rates of the whole MDP and anal side of the pyloric ring were compared between 103 participants who underwent FUSE and 1045 participants who underwent EGD. Pain and discomfort at insertion and during and after the examination were assessed using a visual analog scale in 38 participants who underwent FUSE with a previous examination history of EGD. RESULTS: The successful visualization rates of MDP and the anal side of the pyloric ring in the FUSE group were significantly higher than those in the conventional EGD group; 83.4% versus 35.1% for MDP (P<0.001) and 86.4% versus 7.1% for the anal side of the pyloric ring (P<0.001), respectively. The visual analog scale were not significantly different between FUSE and previous EGD in a portion of the FUSE group. In addition, the detection rate of the periampullary diverticula was also significantly higher in the FUSE group than that in the conventional EGD group (8.7% vs. 1.6%, P<0.001). CONCLUSIONS: This study provides evidence supporting that FUSE is superior to EGD for precise visualization of blind spots in the duodenum.

Endoscopic ultrasound-guided needle-based confocal laser endomicroscopy in gastrointestinal subepithelial lesions: Feasibility study.

BACKGROUND AND AIM: Needle-based confocal laser endomicroscopy (nCLE) allows for real-time optical biopsies during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Little is known about nCLE imaging of gastrointestinal subepithelial lesions (GI-SEL); therefore, we determined its feasibility. METHODS: We carried out EUS, nCLE, and finally FNA in 25 patients with GI-SEL between November 2015 and December 2018. We retrospectively compared nCLE findings with pathological findings of EUS-FNA or surgical specimens. For concordance analysis, two endoscopists independently validated representative nCLE images 5 months or more after examinations. RESULTS: Adequate sample acquisition rate of EUS-FNA was 67% per needle pass and 96% per patient. EUS-FNA was diagnostic in 80% (20/25), suspicious in 4% (1/25), and nondiagnostic in 16% (4/25). nCLE image acquisition rate was 100% and its concordance rate with final pathology was 88% (22/25), which was not significantly different from diagnostic and suspicious EUS-FNA. nCLE could differentiate GI stromal tumors (GISTs) from leiomyoma, in that GISTs were characterized by contrast-enhanced densely populated spindle cell tumors with unenhanced rod-shaped nuclei in 93% of 14 patients, whereas leiomyomas were characterized by narrower spindle cell tumors with fewer and smaller unenhanced nuclei in 100% of three patients. In rectal metastasis from lung adenocarcinoma, some pleomorphic dark nests were observed. At concordance analysis between the two endoscopists' validation results, κ value was 0.560 (P < 0.001), indicating moderate agreement. There were no adverse events associated with nCLE and EUS-FNA. CONCLUSION: Needle-based confocal laser endomicroscopy can be safe and useful for on-site detection of abnormalities of GI-SEL (UMIN 000013857).

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.

Induced miR-31 by 5-fluorouracil exposure contributes to the resistance in colorectal tumors.

Drug resistance makes treatment difficult in cancers. The present study identifies and analyzes drug resistance-related miRNA in colorectal cancer. We established 4 types of 5-fluorouracil (5-FU)-resistant colon cancer cell lines in vitro and in vivo. We then analyzed the miRNA expression profile by miRNA array in these 4 cell lines, and identified the drug resistance-related miRNAs. We examined the expression levels of the identified miRNA in 112 colorectal tumor samples from the patients. We identified 12 possible miRNAs involved in 5-FU resistance by miRNA arrays. We then examined the relationship between miR-31, which was the most promising among them, and drug resistance. The ectopic expression of mimic miR-31 showed significant 5-FU resistance in the parental DLD-1 cells, while anti-miR-31 caused significant growth inhibition in DLD/F cells; that is, 5-FU-resistant colon cancer cell line DLD-1 under exposure to 5-FU. When we exposed high doses of 5-FU to parent or 5-FU-resistant cells, the expression levels of miR-31 were raised higher than those of controls. Notably, the expression levels of miR-31 were positively correlated with the grade of clinical stages of colorectal tumors. The protein expression levels of factors inhibiting hypoxia-inducible factor 1 were downregulated by transfection of mimic miR-31 into DLD-1 cells. This study provides evidence supporting the association of miR-31 with 5-FU drug resistance and clinical stages of colorectal tumors.

Development of a Comorbidity Index to Identify Patients With Small Bowel Bleeding at Risk for Rebleeding and Small Bowel Vascular Diseases.

BACKGROUND & AIMS: We aimed to establish a comorbidity index for small bowel vascular diseases (SBVD) associated with small bowel bleeding (SBB) and recurrent bleeding. METHODS: We performed a retrospective analysis of 404 patients diagnosed with SBB via double-balloon enteroscopy, at 2 hospitals in Japan from June 2003 through July 2016. We collected data on comorbidities, computed Charlson Comorbidity Index and anticoagulation and risk factors in atrial fibrillation (ATRIA) scores, and analyzed associations with SBVD, rebleeding, and overall survival associated with bleeding and/or comorbidities. We used these data to develop a comorbidity index to identify patients at risk for SBVD, rebleeding, and reduced survival time. We validated our findings in a separate, prospective cohort of 88 patients with SBB. RESULTS: We developed a weighted index (the Ohmiya index) that identified patients who developed SBVD with an area under the receiver operating characteristic (AUROC) curve of 0.7758; this value was higher than that of the Charlson index score (0.6828; P < .0001) or ATRIA score (0.6728; P < .0001) alone. Among the 51 patients taking oral anticoagulants, there was no significant difference in AUROCs for the Ohmiya score (0.5254) vs the outcomes registry for better informed treatment score (0.5857; P = .4300). In the retrospective cohort, the Ohmiya index identified patients with SBVD with 68% sensitivity (93/137), 84% specificity (223/267), and 78% accuracy (316/404); in the validation cohort, these values were 63% (22/35), 85% (45/53), and 76% (67/88), respectively. Onset age <50 years and index score <2 identified patients with Meckel's diverticulum and Crohn's disease with 53% accuracy. Onset age ≥50 years and index score <2 identified patients with inflammatory diseases, drug-induced injuries, or tumors with 72% accuracy. An index score ≥2 identified patients with SBVD with 68% accuracy, regardless of age. Among patients with Ohmiya index scores ≥2, 33% had rebleeding; among patients with scores <2, 15% had rebleeding (hazard ratio for score ≥2, 1.729; 95% CI, 1.038-2.882; P = .0355). CONCLUSION: We developed an index, based on comorbidities and age of onset of SBB, that identified patients at risk for rebleeding and vascular disease (for example, enteroscopic hemostasis for SBVD, medication for inflammatory diseases, surgery with enteroscopic tattooing for tumors and diverticula). UMIN: 000025693.

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.

Eradication of Helicobacter pylori Induces Immediate Regressive Changes in Early Gastric Adenocarcinomas.

OBJECTIVE: Helicobacter pylori eradication is expected to prevent gastric cancer. However, morphological alterations after eradication often hinder accurate diagnosis. Therefore, we evaluated endoscopic and histological changes in gastric tumors after eradication of H. pylori in a time-dependent manner. METHODS: We classified 144 cases of endoscopic submucosal dissection (ESD) of early gastric cancer into the following categories: (i) patients positive for H. pylori with no eradication history, (ii) patients positive for H. pylori who underwent ESD 2 months after eradication, (iii) patients negative for H. pylori with an eradication history of at least 6 months before ESD, and (iv) patients negative for H. pylori with an unknown history. We compared endoscopic and histological factors between the groups. RESULTS: The characteristics of cancers positive for H. pylori were exploding shape, superficial high-grade atypical epithelium, and a surface proliferating zone. H. pylori eradication induced a series of endoscopic and histological changes, including shape -depression, appearance of surface regenerative and lower-grade atypical epithelium, and a downward shift of the proliferative zone within a period as short as 2 months. CONCLUSION: H. pylori eradication rapidly causes cancer regression and leads to tumor shrinkage, diminished atypism, and shortened proliferative zone, resulting in drastic morphological changes.

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.

Development and endoscopic appearance of colorectal tumors are characterized by the expression profiles of miRNAs.

Accumulating data indicates that certain microRNAs (miRNAs or miRs) are differently expressed in samples of tumors and paired non-tumorous samples taken from the same patients with colorectal tumors. We previously reported to clarify the relationship between the expression of the miRNAs and the endoscopic morphological appearance of the colorectal tumors. In this report, we focused on colorectal adenoma (tubular or tubulovillous adenoma), or tubular early carcinoma or type 2 adenocarcinoma, familial adenomatous polyposis (FAP), ulcerative colitis-associated tumor (UCAT), and sessile serrated adenoma/polyp (SSA/P). We tried to clarify the relationship between the expression of the miRNAs and the colorectal tumor development. The expression levels of miR-143, -145, and -34a were reduced in most of the polypoid and FAP tumors compared with those in the flat elevated, UCAT, SSA/P ones. In type 2 adenocarcinomas, the expression profile of these miRNAs was similar to those of the polypoid and FAP tumors. The expression levels of miR-7 and -21 were up-regulated in non-granular type of laterally spreading tumor, UCAT, and SSA/P compared with those in polypoid and FAP tumors. These findings indicated that the expression of onco-related miRNAs was closely associated with the development and endoscopic appearance of colorectal tumors.

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.