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Background/Aims: H2 receptor antagonists (H2RA) have been used to treat gastritis by inhibiting gastric acid. Proton pump inhibitors (PPIs) are more potent acid suppressants than H2RA. However, the efficacy and safety of low-dose PPI for treating gastritis remain unclear. The aim was to investigate the efficacy and safety of low-dose PPI for treating gastritis. Methods: A double-blind, noninferiority, multicenter, phase 3 clinical trial randomly assigned 476 patients with endoscopic erosive gastritis to a group using esomeprazole 10 mg (DW1903) daily and a group using famotidine 20 mg (DW1903R1) daily for 2 weeks. The full-analysis set included 319 patients (DW1903, n=159; DW1903R1, n=160) and the per-protocol set included 298 patients (DW1903, n=147; DW1903R1, n=151). The primary endpoint (erosion improvement rate) and secondary endpoint (erosion and edema cure rates, improvement rates of hemorrhage, erythema, and symptoms) were assessed after the treatment. Adverse events were compared. Results: According to the full-analysis set, the erosion improvement rates in the DW1903 and DW1903R1 groups were 59.8% and 58.8%, respectively. According to the per-protocol analysis, the erosion improvement rates in the DW1903 and DW1903R1 groups were 61.9% and 59.6%, respectively. Secondary endpoints were not significantly different between two groups except that the hemorrhagic improvement rate was higher in DW1903 with statistical tendency. The number of adverse events were not statistically different. Conclusions: DW1903 of a low-dose PPI was not inferior to DW1903R1 of H2RA. Thus, lowdose PPI can be a novel option for treating gastritis (ClinicalTrials.gov Identifier: NCT05163756).

With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Abstract Background Proton-pump inhibitors (PPIs) are the most effective drugs for treating acid-related disorders. However, once-daily dosing with conventional PPIs fail to fully control acid secretion over 24 h. This study aimed to compare the efficacy and safety of HIP1601 (dual delayed-release esomeprazole) and HGP1705 (delayed-release esomeprazole) in patients with erosive esophagitis (EE). Methods We enrolled 213 patients with EE randomized in a 1:1 ratio to receive 40 mg HIP1601 (n = 107) or HGP1705 (n = 106) once daily for 4 or 8 weeks. The primary endpoint was the EE healing rate, confirmed by endoscopy up to week 8. GERD-related symptoms and treatment-emergent adverse events were compared between both groups. Results By week 8, the estimated healing rates of EE were 97.8% and 96.8% in the HIP1601 and HGP1705 groups, respectively, with a 95% confidence interval of -4.7 to 7.2. After 4 or 8 weeks of treatment, the EE healing rate at week 4, complete resolution rate of symptoms, time to sustained resolution of symptoms, and number of rescue medications used were similar in both groups. The proportion of heartburn- and acid regurgitation-free nights by week 4 were higher in the HIP1601 group compared to the HGP1705 group, but the difference did not reach clinical significance (87.7% vs. 85.8%, P = 0.514, 87.5% vs. 85.8%, P = 0.774). The number of adverse events did not differ significantly between the two groups. Conclusions The efficacy and safety of HIP1601 40 mg were comparable to those of HGP1705 40 mg for the treatment of EE and symptomatic improvement of GERD. Trial registration NCT04080726 ( https://classic.clinicaltrials.gov/ct2/show/NCT04080726 ), registration date: 25/10/2018.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

AbstractObjective Non-variceal upper gastrointestinal bleeding (NVUGIB) in patients receiving oral anticoagulants (OACs) may be fatal; however, little is known about re-bleeding and all-cause mortality after successful hemostasis. We investigated the clinical characteristics and risk factors for re-bleeding and death after successful hemostasis.Methods Patients receiving OACs and diagnosed with NVUGIB between 2007 and 2021 were enrolled. All NVUGIB incidents were confirmed if definite bleeding in the upper gastrointestinal tract was detected via esophagogastroduodenoscopy.Results A total of 132 patients receiving OACs were diagnosed with NVUGIB. Males were the majority (72, 54.5%), and bleeding was detected mostly in the stomach (99, 75%) and was most often due to peptic ulcers (PU) (88, 66.7%). After successful hemostasis of index NVUGIB, 40 patients (30.3%) experienced re-bleeding. Among them, 15 (37.5%) died, and among those, 3 (2.3%) were related to re-bleeding. Multivariate analysis revealed that duodenal bleeding (odds ratio [OR]: 3.305; 95% confidence interval [CI]: 1.152-9.479, p = 0.026) and Charlson comorbidity index score (CCI) (OR: 1.22; 95% CI: 1.052–1.419, p = 0.009) were significant risk factors for re-bleeding. Index albumin levels (OR: 0.134; 95% CI: 0.035–0.506, p = 0.003), previous PU or upper gastrointestinal bleeding (UGIB) history (OR: 4.626; 95% CI: 1.375–15.567, p = 0.013), and CCI (OR: 1.293; 95% CI: 1.058–1.581, p = 0.012) were related all-cause mortality.Conclusion CCI and duodenal bleeding are risk factors for re-bleeding in patients with NVUGIB who were receiving OACs, while low index albumin levels and previous PU and UGIB history are associated with all-cause mortality.

Background/Aims: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the stomach. We evaluated the clinical outcomes of endoscopic treatment for gastric GISTs. Methods: This is a single center, retrospective study that enrolled 135 cases of gastric subepithelial tumors (SETs) resected by endoscopic procedures and confirmed as GISTs by histopathology from March 2005 to July 2019. The immediate and long-term clinical outcomes were analyzed retrospectively. Results: The mean patient age was 57.9 years, and the mean tumor size was 2.1 cm. Of the tumors, 43.0% were located in the body, followed by the fundus (26.7%) and cardia (17.0%). Most tumors (85.2%) were resected by endoscopic submucosal dissection, followed by endoscopic mucosal resection (6.7%), submucosal tunneling endoscopic resection (5.9%), and endoscopic full-thickness resection (2.2%). Macroperforation occurred in 4.4% and microperforation in 6.7% of the cases. The R0 resection rate was 15.6%. However, the rate of complete resection by the endoscopic view was 90.4%, of which 54.8% of cases were in the very-low-risk group, followed by the low-risk group (28.1%), intermediate-risk group (11.9%), and high-risk group (5.2%). During 36.5 months of follow-up, recurrence was found in four (3.4%) of the 118 patients who were monitored for more than 6 months (low-risk group, 1/37 [2.7%]; intermediate-risk group, 2/11 [18.2%]; high-risk group, 1/6 [16.7%]). Conclusions: Endoscopic treatment of a GIST appears to be a feasible procedure in selected cases. However, additional surgery should be considered if the pathologic results correspond to intermediate- or high-risk groups.

Background/Aims: Endoscopic submucosal dissection (ESD) of gastric neoplasm involving the pyloric channel (GNPC) is technically challenging due to difficulty in precise assessment of resection margin and inadequate visualization. The aim of this study was to evaluate the effectiveness and long-term outcome of ESD for GNPC and introduce a noble technique for resection of GNPC. Methods: A total of 97 patients with GNPC underwent ESD from January 2007 to October 2017. We divided them into a conventional anterograde resection group and a retrograde resection group according to the method of procedure. We compared their clinical outcomes and investigated risk factors for postprocedural complications. Results: The en bloc resection rate was 87.6%, and complete resection rate was 83.5%. Postprocedure stenosis occurred in 16 cases (16.5%). GNPCs of the retrograde resection group were more frequently located from antrum to bulb, were significantly larger, were related to ≥75% resection of the circumference, and involved significantly longer procedure times than those in the anterograde resection group. Multivariate analysis showed that resection ≥75% of the circumference was the only significant risk factor for postprocedure stenosis. Conclusions: ESD by retrograde resection method is a novel technique to make the procedure easier, depending on the size, location, and circumference of resection.

Abstract Various omics-based biomarkers related to the occurrence, progression, and prognosis of colorectal cancer (CRC) have been identified. In this study, we attempted to identify gut microbiome-based biomarkers and detect their association with host gene expression in the initiation and progression of CRC by integrating analysis of the gut mucosal metagenome, RNA sequencing, and sociomedical factors. We performed metagenome and RNA sequencing on colonic mucosa samples from 13 patients with advanced CRC (ACRC), 10 patients with high-risk adenoma (HRA), and 7 normal control (NC) individuals. All participants completed a questionnaire on sociomedical factors. The interaction and correlation between changes in the microbiome and gene expression were assessed using bioinformatic analysis. When comparing HRA and NC samples, which can be considered to represent the process of tumor initiation, 28 genes and five microbiome species were analyzed with correlation plots. When comparing ACRC and HRA samples, which can be considered to represent the progression of CRC, seven bacterial species and 21 genes were analyzed. When comparing ACRC and NC samples, 16 genes and five bacterial species were analyzed, and four correlation plots were generated. A network visualizing the relationship between bacterial and host gene expression in the initiation and progression of CRC indicated that Clostridium spiroforme and Tyzzerella nexilis were hub bacteria in the development and progression of CRC. Our study revealed the interactions of and correlation between the colonic mucosal microbiome and host gene expression to identify potential roles of the microbiome in the initiation and progression of CRC. Our results provide gut microbiome-based biomarkers that may be potential diagnostic markers and therapeutic targets in patients with CRC.

Background: Patients undergoing dual antiplatelet therapy (DAPT) may experience recurrent gastrointestinal bleeding (GIB). We investigated the clinical characteristics and risk factors for recurrent non-variceal upper gastrointestinal bleeding (NVUGIB) in patients who had experienced NVUGIB while receiving DAPT. Methods: We enrolled patients diagnosed with NVUGIB while receiving DAPT between 2006 and 2020. Definite bleeding was confirmed by esophagogastroduodenoscopy in all NVUGIB patients. Results: A total of 124 patients were diagnosed with NVUGIB while receiving DAPT. They were predominantly male (n = 103, 83.1%), bleeding mostly from the stomach (n = 94, 75.8%) and had peptic ulcers (n = 72, 58.1%). After the successful hemostasis of NVUGIB, 36 patients (29.0%) experienced at least one episode of recurrent upper GIB, 19 patients (15.3%) died, and 7 (5.6%) patients had a bleeding-related death. Multivariate analysis showed that age was a significant factor for re-bleeding (odds ratio [OR], 1.050; 95% confidence interval [CI]: 1.001–1.102; p-value: 0.047), all-cause mortality (OR, 1.096; 95% CI: 1.020–1.178, p = 0.013), and re-bleeding-related mortality (OR, 1.187; 95% CI: 1.032–1.364, p-value: 0.016). In Kaplan–Meier analysis, the cumulative probabilities of re-bleeding, death, and bleeding-related death were significantly higher in patients aged 70 and older (p = 0.008,

Background/Aims: The mucoprotective drug rebamipide is used to treat gastritis and peptic ulcers. We compared the efficacy of MucostaⓇ (rebamipide 100 mg) and its new formulation, AD-203 (rebamipide 150 mg), in treating erosive gastritis. Methods: This double-blind, active control, noninferiority, multicenter, phase 3 clinical trial randomly assigned 475 patients with endoscopically proven erosive gastritis to two groups: AD-203 twice daily or MucostaⓇ thrice daily for 2 weeks. The intention-to-treat (ITT) analysis included 454 patients (AD-203, n=229; MucostaⓇ, n=225), and the per-protocol (PP) analysis included 439 patients (AD-203, n=224; MucostaⓇ, n=215). The posttreatment assessments included the primary (erosion improvement rate) and secondary endpoints (erosion and edema cure rates; improvement rates of redness, hemorrhage, and gastrointestinal symptoms). Drug-related adverse events were evaluated. Results: According to the ITT analysis, the erosion improvement rates (posttreatment) in AD-203-treated and MucostaⓇ-treated patients were 39.7% and 43.8%, respectively. According to the PP analysis, the erosion improvement rates (posttreatment) in AD-203-treated and MucostaⓇ-treated patients were 39.3% and 43.7%, respectively. The one-sided 97.5% lower limit for the improvement rate difference between the study groups was −4.01% (95% confidence interval [CI], –13.09% to 5.06%) in the ITT analysis and −4.44% (95% CI, –13.65% to 4.78%) in the PP analysis. The groups did not significantly differ in the secondary endpoints in either analysis. Twenty-four AD-203-treated and 20 MucostaⓇ-treated patients reported adverse events but no serious adverse drug reactions; both groups presented similar adverse event rates. Conclusions: The new formulation of rebamipide 150 mg (AD-203) twice daily was not inferior to rebamipide 100 mg (MucostaⓇ) thrice daily. Both formulations showed a similar efficacy in treating erosive gastritis.

Background/Aims The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP). Methods A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs. Results For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p

Background/Aims Small bowel malignancies often present a diagnostic challenge due to their relative rarity and nonspecific clinical symptoms. However, technical developments in endoscopic instruments, including video capsule endoscopy (VCE) and enteroscopy, have allowed for the visualization of the entire small bowel. This study aimed to investigate the clinicopathological features of small bowel malignant tumors diagnosed by VCE and double-balloon enteroscopy (DBE) in a single tertiary center. Methods We retrospectively analyzed VCE and DBE findings from Korea University Guro Hospital from January 2010 through September 2018. Results A total of 510 VCE and 126 DBE examinations were performed in 438 patients. Small bowel malignancies were diagnosed in 28 patients (15 males; mean age, 61.0 years; range, 42 to 81 years). Among them, 8 had lymphoma, 8 had primary adenocarcinoma, 7 had gastrointestinal stromal tumor (GIST) and 5 had metastatic cancer. Abdominal pain and obstructive symptoms were the most common findings in metastatic cancers (4/5, 80%). On the other hand, obscure gastrointestinal bleeding was the most common symptom of GIST (6/7, 85.7%) and adenocarcinoma (3/8, 37.5%). Conclusions Approximately 6% of the patients who underwent either VCE or DBE were diagnosed with small bowel malignancy. These findings demonstrated the different clinical characteristics among small bowel malignancies and merit further study.

Background/Aims Oral sulfate solution (OSS) is an emerging cleansing agent for bowel preparation. However, data comparing OSS to other conventional bowel preparations in Asian patients are limited. Therefore, the objective of this study was to compare the efficacy and tolerability of OSS to ascorbic acid plus polyethylene glycol (AA + PEG) in Asian patients. Methods This was a prospective, randomized, parallel, investigator-blind study performed in two university hospitals in Korea. Bowel preparation efficacy was evaluated using both the Ottawa Bowel Preparation Scale (OBPS) and Boston Bowel Preparation Scale (BBPS). Results Among 173 patients, 86 received OSS while 87 received AA + PEG for bowel preparation. Total OBPS score was 2.80 ± 2.48 in the OSS group and 4.49 ± 3.08 in the AA + PEG group, indicating significantly (p < 0.001) better efficacy with OSS. Total BBPS was higher in the OSS group (7.43 ± 1.49 vs. 6.51 ± 1.76, p < 0.001), indicating superior bowel preparation quality with OSS. Preparation-related adverse events were generally acceptable. Patients receiving OSS had more nausea (1.92 ± 0.94 vs. 1.54 ± 0.76, p = 0.004) and abdominal cramping (1.45 ± 0.78 vs. 1.17 ± 0.51, p = 0.006) than those receiving AA + PEG. However, overall satisfaction and taste were similar between the two groups. Conclusions OSS had a non-inferior bowel cleansing efficacy than AA + PEG regardless of colon segment.

A microsatellite instability (MSI) test is crucial for screening for HNPCC (Hereditary nonpolyposis colorectal cancer; Lynch syndrome) and optimization of colorectal cancer (CRC) treatment. Mismatch repair (MMR) deficiency is a predictor for good response of immune checkpoint inhibitors in various malignancies. In this study, we evaluated the results of a newly developed plasma-based real-time PCR kit for the detection of MSI in CRC patients. We assessed a peptide nucleotide acid (PNA) probe-mediated real-time PCR test (U-TOP MSI Detection Kit Plus) that determines MSI status by using amplicon melting analysis of five markers (NR21, NR24, NR27, BAT25, and BAT26) from plasma. Eighty-four CRC patients (46 dMMR and 38 pMMR) with colorectal cancer were analyzed. The concordance rate of MSI status assessment between the plasma kit and IHC was 63.0% in dMMR patients (29/46), but in the pMMR evaluation, a 100% (38/38) concordance rate was observed. In the evaluation of the performance of a custom tissue U-TOP MSI Detection Kit and plasma kit in 28 patients, sensitivity, specificity, PPV (positive predictive value) and NPV (negative predictive value) of plasma kit were 68.4, 100, 100, and 44.4%, respectively, with the tissue U-TOP MSI Detection Kit. Our results demonstrate the feasibility of a non-invasive and rapid plasma-based real-time PCR kit (U-TOP MSI Detection Kit Plus) for the detection of MSI in colorectal cancer.

Background/AimsTo evaluate the efficacy and safety of a controlled release, once-daily formulation of mosapride (UI05MSP015CT) in patients with functional dyspepsia (FD).Methods : Patients with FD were randomly assigned (1:1) to receive either UI05MSP015CT (15 mg once a day, study group) or mosapride (5 mg three times a day, control group) and corresponding placebo for 4 weeks. The primary endpoint was a change in the gastrointestinal symptom score (GIS) evaluated at enrollment and after 4 weeks. Secondary endpoints were changes in the Nepean Dyspepsia Index-Korean version (NDI-K), rate of satisfactory symptom relief, and rate of adverse events.Results : A total of 138 patients were enrolled (female, 73.9%; mean age, 44.0±15.4 years). After excluding patients who violated the study protocol, 59 and 58 patients from the study and control groups, respectively, were included in the per-protocol analysis. No difference was observed in drug compliance between the control and study groups (97.07%±4.52% vs 96.85%±6.05%, p=0.870). Changes in GIS scores were 9.69±6.44 and 10.01±5.92 in the study and control groups. The mean difference in GIS change between groups was 0.33 (95% confidence interval, 1.75 to 2.41), demonstrating non-inferiority of UI-05MSP015CT (p=0.755). The rate of satisfactory symptom relief was not different between the study and control groups (39.0% vs 56.9%, p=0.053). No differences in change in NDI-K score (14.3 vs 16.9, p=0.263) or rates of adverse events (12.9% vs. 4.4%, p=0.062) were observed between the study and control groups.Conclusion : sOnce-daily mosapride is not inferior to conventional mosapride in efficacy and is safe in patients with FD.

Abstract Background We investigated the inhibitory effect of pantoprazole on signal transducer and activator of transcription 3 (STAT3) activity and invasiveness of gastric adenocarcinoma cells, and the role of SH2-containing protein tyrosine phosphatase 1 (SHP-1) in mediating role. Methods We used AGS and MKN-28 cells because of reduced SHP-1 and preserved p-STAT3 expression. Western blot, wound closure assay, Matrigel invasion assay and 3-D culture invasion assay were performed. Pharmacologic inhibitor of SHP-1 and siRNA were used for validation of the role of SHP-1. Results We observed that pantoprazole at 40, 80, and 160 μg/ml upregulated SHP-1 and downregulated p-STAT3 expression in a dose-dependent manner in AGS and MKN-28 cells. Furthermore, pantoprazole significantly downregulated mesenchymal markers (Snail1 and vimentin), upregulated epithelial marker (E-cadherin), and inhibited migration and invasion of AGS and MKN-28 cells. To validate the role of SHP-1 in inhibition of STAT3 activity by pantoprazole in gastric cancer cells, we performed pharmacologic inhibition (pervanadate) or knockdown of SHP-1 before pantoprazole treatment, which significantly attenuated the suppression of p-STAT3 and anti-migration and invasion effect by pantoprazole in AGS cells. In xenograft tumor model, tumor volume was significantly reduced by intraperitoneal injection of pantoprazole, with upregulation of SHP-1 and downregulation of p-STAT3, which were attenuated by concomitant injection of pervanadate. Conclusion Our data suggest that the inhibitory effect of pantoprazole on cellular migration and invasion might be through inducing SHP-1 in gastric cancer cells.

Background/Aims Rebleeding is associated with mortality in patients with peptic ulcer bleeding (PUB), and risk stratification is important for the management of these patients. The purpose of our study was to examine the risk factors associated with rebleeding in patients with PUB. Methods : The Korean Peptic Ulcer Bleeding registry is a large prospectively collected database of patients with PUB who were hospitalized between 2014 and 2015 at 28 medical centers in Korea. We examined the basic characteristics and clinical outcomes of patients in this registry. Univariate and multivariate analyses were performed to identify the factors associated with rebleeding. Results : In total, 904 patients with PUB were registered, and 897 patients were analyzed. Rebleeding occurred in 7.1% of the patients (64), and the 30-day mortality was 1.0% (nine patients). According to the multivariate analysis, the risk factors for rebleeding were the presence of co-morbidities, use of multiple drugs, albumin levels, and hematemesis/hematochezia as initial presentations. Conclusion : s The presence of co-morbidities, use of multiple drugs, albumin levels, and initial presentations with hematemesis/hematochezia can be indicators of rebleeding in patients with PUB. The wide use of proton pump inhibitors and prompt endoscopic interventions may explain the low incidence of rebleeding and low mortality rates in Korea.

Abstract Background We investigated the effect of arsenic trioxide (ATO) for inhibition of signal transducer and activator of transcription 3 (STAT3) and epithelial-mesenchymal transition (EMT) in gastric cancer cells, and the role of SH2 domain-containing phosphatase-1 (SHP-1) during this process. Methods We used AGS cells, which showed minimal SHP-1 expression and constitutive STAT3 expression. After treatment of ATO, cellular migration and invasion were assessed by using wound closure assay, Matrigel invasion assay and 3-D culture invasion assay. To validate the role of SHP-1, pervanadate, a pharmacologic phosphatase inhibitor, and SHP-1 siRNA were used. Xenograft tumors were produced, and ATO or pervanadate were administered via intraperitoneal (IP) route. Results Treatment of ATO 5 and 10 μM significantly decreased cellular migration and invasion in a dose-dependent manner. Western blot showed that ATO upregulated SHP-1 expression and downregulated STAT3 expression, and immunofluorescence showed upregulation with E-cadherin (epithelial marker) and downregulation of Snail1 (mesenchymal marker) expression by ATO treatment. Anti-migration and invasion effect and modulation of SHP-1/STAT3 axis by ATO were attenuated by pervanadate or SHP-1 siRNA. IP injection of ATO significantly decreased the xenograft tumor volume and upregulated SHP-1 expression, which were attenuated by co-IP injection of pervanadate. Conclusion Our data suggest that ATO inhibits STAT3 activity and EMT process by upregulation of SHP-1 in gastric cancer cells.

Background/AimsIn addition to the globally endorsed Barcelona Clinic Liver Cancer (BCLC) staging system, other algorithms or staging systems have been developed, including the Hong Kong Liver Cancer (HKLC) staging system. This study aimed to validate the HKLC staging system relative to the BCLC staging system for predicting survival for hepatocellular carcinoma (HCC) patients in Korea.Methods : From 2004 to 2013, 2,571 patients newly diagnosed with HCC were consecutively enrolled at three Korea University medical centers.Results : Both staging systems differentiated survival well (p

Background/Aims Patients may feel embarrassed during colonoscopy. Our study aimed to assess changes in patient preference, over the past decade, for the sex of their colonoscopist. Methods Prospective studies were performed at a single health center from July to September 2008, and from July to September 2016. Subjects included colonoscopy patients (2008: 354, 2016: 304) who were asked to complete a questionnaire before colonoscopy. Results In 2016, 69 patients (24.9%) expressed a sex preference, compared with 46 patients (14.6%) in 2008. By 2016, female patient preference for a female colonoscopist had significantly increased to 95% (odds ratio [OR], 2.678; 95% confidence interval [CI], 1.418– 5.057; P=0.002). In multivariate analysis, patient sex (OR, 4.404; P=0.000), patient age (OR, 0.977; 95% CI, 0.961–0.992; P=0.004), and year of procedure (OR, 1.674; 95% CI, 1.028–2.752) were statistically significant factors in sex preference. Between 2008 and 2016, female patients preferred a female colonoscopist because of embarrassment. Male patients also preferred a male colonoscopist, and the primary reason shifted from expertise to patient embarrassment (2008: 29%, 2016: 63%). Conclusions Patients have an increased gender preference for the colonoscopist because of embarrassment. Taking this into account can increase patient satisfaction during colonoscopy.

Video capsule endoscopy (VCE) is an effective diagnostic modality for detecting small bowel lesions. However, the value of VCE for patients with chronic recurrent abdominal pain (CAP) of unknown etiology remains obscure. We retrospectively analyzed factors that could predict enteropathy based on the medical records of 65 patients with unexplained chronic recurrent abdominal pain (CAP) who were assessed using VCE between 2001 and 2021. We also conducted a systematic review and meta-analysis of the literature to validate our results. The positive findings of 27 (41.5%) of the 65 patients were mostly ulcerative lesions including stricture (n = 14, 60.9%) and erosion (n = 8, 29.7%). Multivariate analysis identified elevated ESR (OR, 1.06, 95% CI, 1.02–1.1, p = 0.004) as a significant risk factor for enteropathy predicted by VCE. Three eligible studies in the meta-analysis included 523 patients with CAP. Elevated C-reactive protein (CRP) (OR, 14.09; 95% CI, 2.81–70.60; p = 0.001) and erythrocyte sedimentation rate (ESR) (OR, 14.45; 95% CI, 0.92–227.33; p = 0.06) indicated VCE-positive findings in patients with unexplained abdominal pain. Elevated levels of the inflammatory markers ESR and CRP can thus predict positive VCE findings in patients with CAP.

Previous studies reported substantial differences between proximal and distal gastric cancer, however, most of the cases included in these studies were advanced gastric cancers (AGCs). The aim of this study was to investigate the unique characteristics of proximal early gastric cancer (EGC) by comparing with distal EGC. From March 2007 to March 2016, proximal and distal EGC patients who underwent endoscopic or surgical resection at our institution were matched 1:3 according to age and sex. We retrospectively analyzed the clinical and histopathological information. A total of 368 patients were enrolled including 92 (25%) in the proximal and 276 (75%) in the distal group. The proportion of patients who underwent surgery (56.5 vs. 20.3%, p

Melanocytic nevus is the benign proliferation of melanocytes. The most common location of melanocytic nevus is the skin of the extremities; however, there are few case reports of melanocytic nevus at the rectal mucosa. No prior case of malignant melanoma from melanocytic nevus at the rectal mucosa has been reported; therefore, it is unclear whether resection should be performed or close observation is sufficient. However, the potential malignant transformation of melanocytic nevus should be considered, including melanocytic nevus on the rectum. Melanocytic nevus of the skin can be removed by surgical excision; however, due to rare incidence on the mucosa of the gastrointestinal tract, the optimal treatment for rectal melanocytic nevus remains controversial. Here, we report the first case of melanocytic nevus on the rectal mucosa that was removed by endoscopic submucosal dissection. This case report provides useful information about the optimal management of rectal melanocytic nevus.

Background/AimsAstaxanthin is a carotenoid pigment that has antioxidant, antitumoral, and anti-inflammatory properties. In this in vitro study, we investigated the mechanism of anticancer effects of astaxanthin in gastric carcinoma cell lines.Methods : The human gastric adenocarcinoma cell lines AGS, KATO-III, MKN-45, and SNU-1 were treated with various concentrations of astaxanthin. A cell viability test, cell cycle analysis, and immunoblotting were performed.Results : The viability of each cancer cell line was suppressed by astaxanthin in a dose-dependent manner with significantly decreased proliferation in KATO-III and SNU-1 cells. Astaxanthin increased the number of cells in the G0/G1 phase but reduced the proportion of S phase KATO-III and SNU-1 cells. Phosphorylated extracellular signal-regulated kinase (ERK) was decreased in an inverse dose-dependent correlation with astaxanthin concentration, and the expression of p27kip-1 increased the KATO-III and SNU-1 cell lines in an astaxanthin dose-dependent manner.Conclusion : sAstaxanthin inhibits proliferation by interrupting cell cycle progression in KATO-III and SNU-1 gastric cancer cells. This may be caused by the inhibition of the phosphorylation of ERK and the enhanced expression of p27kip-1.

An inverted hyperplastic polyp (IHP) found in stomach is rare and characterized by downward growth of hyperplastic mucosal component into the submucosa. Because of such characteristic, IHP can be misdiagnosed as subepithelial tumor or malignant tumor. In fact, adenocarcinoma was reported to have coexisted with gastric IHP in several previous reports. Because only 18 cases on gastric IHP have been reported in English and Korean literature until now, pathogenesis and clinical features of gastric IHP and correlation with adenocarcinoma have not been clearly established. Herein, we report a case of gastric IHP which was initially misdiagnosed as gastrointestinal stromal tumor and resected using endoscopic submucosal dissection. Literature review of previously published case reports on gastric IHP is also presented. (Korean J Gastroenterol 2016;67:98-102)

Small bowel tumors are very rare and generally malignant. As a result of the anatomical location and nonspecific manifestations of small bowel tumors, they are very difficult to diagnose. Balloon-assisted enteroscopy is a relatively noninvasive method compared to surgical resection, and allows for real-time observation, tissue confirmation with biopsy, and interventional procedures. Here, we report the case of a 69-year-old woman with a small bowel metastatic carcinoma observed with double balloon enteroscopy (DBE). She had a history of multiple cancers including ovarian cancer, bladder cancer, and breast cancer. The antegrade DBE procedure was performed before surgery for biopsy tissue confirmation. The patient underwent small bowel resection, and the final diagnosis was the same as that determined by preoperative biopsy. The final diagnosis was metastatic small bowel cancer originating from a cancer of the breast. This is the first detailed report of the preoperative diagnosis of small intestinal metastatic breast cancer by DBE.

Endoscopic resection of gastric subepithelial tumors (SETs) has several advantages over biopsy techniques, such as superior diagnostic yield and definite diagnosis. Removal of gastric SETs and histopathologic confirmation should be considered whenever gastric SETs are highly suspected to have malignant potential such as gastrointestinal stromal tumor (GIST) or neuroendocrine tumor. According to our clinical experience, we suggest that endoscopic resection of gastric SETs is feasible for GISTs less than 3.0 cm without positive endoscopic ultrasonography findings or for hypoechoic SETs less than 3.0 cm. However, serious complications such as macroperforation may occur during endoscopic resection, and this procedure is highly dependent on endoscopists’ skills. We recently reported the long-term clinical outcomes of endoscopic resection of gastric GIST, which showed a relatively low recurrence rate (2.2%) during long-term follow-up (46.0±28.5 months) despite the low R0 resection rate (25.0%). We suggest that endoscopic surveillance might be possible without additional surgical resection in completely resected GISTs without residual tumor confirmed to be lower risk, even if they show an R1 resection margin.

Background/Aims: Tegoprazan is a novel potassium-competitive acid blocker that has beneficial effects on acid-related disorders such as gastroesophageal reflux and peptic ulcer diseases. This study aimed to validate the effect of tegoprazan on endoscopic submucosal dissection (ESD)-induced artificial ulcers. Methods: Patients from 16 centers in Korea who underwent ESD for gastric neoplasia were enrolled. After ESD, pantoprazole was administered intravenously for 48 hours. The patients were randomly allocated to either the tegoprazan or esomeprazole group. Tegoprazan 50 mg or esomeprazole 40 mg were administered for 4 weeks, after which gastroscopic evaluation was performed. If the artificial ulcer had not healed, the same dose of tegoprazan or esomeprazole was administered for an additional 4 weeks, and a gastroscopic evaluation was performed. Results: One hundred sixty patients were enrolled in this study. The healing rates of artificial ulcers at 4 weeks were 30.3% (23/76) and 22.1% (15/68) in the tegoprazan and esomeprazole groups, respectively (p=0.006). At 8 weeks after ESD, the cumulative ulcer healing rates were 73.7% (56/76) and 77.9% (53/68) in the tegoprazan and esomeprazole groups, respectively (p=0.210). Delayed bleeding occurred in two patients in the tegoprazan group (2.6%) and in one patient in the esomeprazole group (1.5%). Other adverse events were negligible in both groups. Conclusions: Tegoprazan showed similar effects on post-ESD artificial ulcer healing in comparison with esomeprazole. [ABSTRACT FROM AUTHOR]