Prospective Evaluation of a New Liquid-Type Rapid Urease Test Kit for Diagnosis of Helicobacter pylori

BACKGROUND/AIMS

Rapid and accurate diagnostic tools are essential for the timely recognition of Helicobacter pylori (H. pylori) in clinical practice. The rapid urease test (RUT) is a comparatively accurate and time-saving method recommended as a first-line diagnostic test. The primary objective of conducting the RUT is to obtain rapid results, thus enabling the initiation of an eradication therapy based on clarithromycin resistance testing. This study aimed to assess the reaction time and accuracy of a new liquid-type RUT.

METHOD

In this prospective study, consecutive dyspeptic or check-up patients referred to our clinic for endoscopy were assessed to evaluate the rapidity and accuracy of a novel liquid-type RUT (Helicotest®, WON Medical, Bucheon, Republic of Korea) compared with another commercial RUT kit (HP kit, Chong Kun Dang, Seoul, Republic of Korea) and a real-time quantitative PCR-based assay (Seeplex® H.pylori-ClaR Detection, Seegene, Republic of Korea). RUTs were analyzed at 10 min, 30 min, 60 min, and 120 min.

RESULTS

Among the 177 enrolled patients, 38.6% were infected with H. pylori. The positivity rates of the liquid-type RUT were 26.1, 35.8, 39.2%, and 41.5% at 10, 30, 60, and 120 min, respectively. When compared with the HP kit test, the time needed to confirm positivity was significantly reduced by 28.6 min (95% CI, 16.60-39.73, p < 0.0001). Helicotest® had a greater accuracy (96.02 ± 1.47), sensitivity (98.53 ± 1.46) and NPV (99.03 ± 0.97) compared to the HP kit.

CONCLUSIONS

Compared to the commonly used RUT, the new liquid-type RUT presented faster and reliable results. Such findings could improve H. pylori treatment outcomes, particularly in outpatient clinical settings.

Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy

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.

Recurrent Non-Variceal Upper Gastrointestinal Bleeding among Patients Receiving Dual Antiplatelet Therapy

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, <0.001, and 0.009, respectively).

CONCLUSIONS

Clinicians should be cautious about re-bleeding and mortality in elderly patients who experience NVUGIB while receiving DAPT.

[Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy]

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.

Clinical practice guideline for percutaneous endoscopic gastrostomy

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.

Clinical Efficacy and Safety of Endoscopic Treatment of Gastrointestinal Stromal Tumors in the Stomach

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.

Clinical outcomes of endoscopic resection of gastric GIST

383

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in stomach. We evaluated the long-term clinical outcomes of endoscopic treatment for gastric GISTs. Methods: This is a retrospective study that enrolled 135 cases of gastric subepithelial tumors (SETs) resected by endoscopic procedures and confirmed as GISTs by histopathology from 2005 to 2019. The immediate and long-term clinical outcomes were analyzed retrospectively. Results: The mean age was 57.9 years, and the mean tumor size was 2.1 cm. Of the tumors, 43.0% were located in the corpus, followed by the fundus (26.7%) and cardia (17.0%). Most tumors (85.2%) were resected by endoscopic submucosal dissection. Macroperforation occurred in 4.4% and microperforation in 6.7% of the cases. The R0 resection rate was 15.6%. However, complete resection by the endoscopic view was 90.4%, of which 54.8% were in the very-low-risk group, followed by the low (28.1%), intermediate (11.9%), and high-risk groups (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 six 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 pathologic result is corresponding to intermediate or high risk group.

Local recurrence after curative resection of early gastric cancer by endoscopic submucosal dissection

388

Background: We investigate the local recurrence rate and its risk factors among patients who underwent endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and are judged as curative resection. Methods: We enrolled patients who were diagnosed as EGC and underwent ESD during 2006 and 2020. Local recurrence after ESD was confirmed by histopathologic evaluation by endoscopic biopsy at ESD site during endoscopic surveillance. Results: A total of 936 patients underwent ESD for EGC, achieved curative resection and were followed up more than 12 months. Among them, 14 cases of local recurrence were found (14/936, 1.5%) during 53.2 months of follow-up. Compared with patients without local recurrence, those with local recurrence showed male-predominance (677/922 vs. 14/14, P=0.025), frequent presence of synchronous tumor (123/922 vs. 6/14, P=0.001) and larger tumor size (16.3 vs. 26.3 mm, P=0.001). Kaplan-Meier graph also showed that local recurrence significantly occurred in subgroup with male, presence of synchronous tumor and tumor size ≥ 20 mm ( P=0.028, 0.009 and <0.001 by log rank test, respectively). After propensity score matching for gender, age and comorbidities with 1:5 ratio, tumor size ≥ 20 mm was the only significant factor for local recurrence (odds ratio: 3.886, 95% confidence interval: 1.012-14.922, P=0.048) Conclusions: Endoscopists need to be cautious for local recurrence at ESD site even after curative resection of EGC, especially for large tumor size.

Re-bleeding and all-cause mortality risk in non-variceal upper gastrointestinal bleeding: focusing on patients receiving oral anticoagulant therapy

OBJECTIVE

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.

Ten-year trends of utilizing palliative care and palliative procedures in patients with gastric Cancer in the United States from 2009 to 2018 - a nationwide database study

Objectives

Little is known about the current status and the changing trends of hospitalization and palliative care consultation of patients with gastric cancer in the United States. The aim of this study was to evaluate the changing trend in the number of hospitalization, palliative care consultation, and palliative procedures in the US during a recent 10-year period using a nationwide database.

Methods

This was a retrospective study that analyzed the National Inpatient Sample (NIS) database of 2009–2018. Patients aged more than 18 years who were diagnosed with a gastric cancer using International Classification of Diseases (ICD)-9 and 10 codes were included. Palliative care consultation included palliative care (ICD-9, V66.7; ICD-10, Z51.5) and advanced care planning (ICD-9, V69.89; ICD-10, Z71.89). Palliative procedures included percutaneous or endoscopic bypass, gastrostomy or enterostomy, dilation, drainage, nutrition, and irrigation for palliative purpose.

Results and discussion

A total of 86,430 patients were selected and analyzed in this study. Using a compound annual growth rate (CAGR) approach, the annual number of hospitalizations of gastric cancer patients was found to be decreased during 2009–2018 (CAGR: -0.8%, P = 0.0084), while utilization rates of palliative care and palliative procedures increased (CAGR: 9.3 and 1.6%, respectively; P < 0.0001). Multivariable regression analysis revealed that palliative care consultation was associated with reduced total hospital charges (−$34,188, P < 0.0001).

Conclusion

Utilization of palliative care consultation to patients with gastric cancer may reduce use of medical resources and hospital costs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07404-1.

Detection of Microsatellite Instability in Colorectal Cancer Patients With a Plasma-Based Real-Time PCR Analysis

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.

Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea

Background

Treatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage.

Methods

Patients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected.

Results

A total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival.

Conclusion

The majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.

Palliative Care and Life-Sustaining/Local Procedures in Colorectal Cancer in the United States Hospitals: A Ten-Year Perspective

Background

In recent years, palliative care utilization has been increasing while life-sustaining/local procedures have been declining at the end of life. Palliative care utilization widely varies based on tumor type. Limited information is available on inpatient palliative care in colorectal cancer.

Aims

This study investigated inpatient palliative care utilization and its association with patient demographics, hospital charges, and procedures among colorectal cancer patients admitted to US hospitals between 2008 and 2017. Receipt of life-sustaining and local procedures and surgeries were also investigated during the ten years.

Methods

Data were extracted from the National inpatient sample (NIS) database containing de-identified information from each hospitalization. Codes V66.7 for ICD-9-CM or Z51.5 for ICD-10-CM were used to find palliative care utilization. Data were analyzed using generalized regression with adjustment for variations in predictors. The Compound Annual Growth Rate (CAGR) was calculated for palliative care and procedures over time.

Results

Of the 487,027 colorectal cancer hospitalizations, only 6.04% utilized palliative care. This percentage significantly increased over time from 2.3% in 2008 to 9.3% in 2017 (P<0.0001). Palliative care utilization sizably decreased hospital charges by $18,010 per hospitalization (P<0.0001) and was positively associated with female gender, severe disease, and age over 80 years (P≤ 0.05). Palliative care utilization was inversely associated with using life-sustaining and local procedures and surgeries (P<0.0001). Life-sustaining procedures (intubation, infusion of concentrate nutrients, dialysis, and blood transfusion) and surgeries were decreased over time (P<0.001).

Conclusions

Palliative care utilization increased over time and was inversely associated with hospital charges and performing procedures among colorectal cancer patients. Our findings warrant further research and interventions to increase palliative care utilization in colorectal cancer.

Endoscopic Resection of Gastrointestinal Stromal Tumor: Is It Safe?

Recently, results from clinical studies of endoscopic resection of gastrointestinal stromal tumor (GIST) in the stomach are being reported. This procedure has several advantages, such as the provision of a definite diagnosis and therapeutic plan, avoidance of frequent follow-up examination, and reduction of patients’ anxiety. However, several concerns also exist such as a limited number of studies, low R0 resection rate, and relatively shorter follow-up period compared with surgical resection. Nevertheless, it is encouraging that most of the post-procedural complications have been treated with conservative management and that some of the patients did not show recurrence of the tumor during long-term follow-up. The selection of suitable cases and the experience of the endoscopists are the most important factors for successful endoscopic resection of gastric GIST. Development of novel procedures as well as collaboration with laparoscopic surgeons are currently in progress.

Clinical Guidelines for Drug-Related Peptic Ulcer, 2020 Revised Edition

Korean guidelines for nonsteroidal anti-inflammatory drug (NSAID)-induced peptic ulcer were previously developed in 2009 with the collaboration of the Korean College of Helicobacter and Upper Gastrointestinal Research and Korean Society of Gastroenterology. However, the previous guidelines were based mainly upon a review of the relevant literature and expert opinion. Therefore, the guidelines need to be revised. We organized a guideline Development Committee for drug-related peptic ulcer under the auspices of the Korean College of Helicobacter and Upper Gastrointestinal Research in 2017 and developed nine statements, including four for NSAIDs, three for aspirin and other antiplatelet agents, and two for anticoagulants through a de novo process founded on evidence-based medicine that included a literature search and a meta-analysis, A consensus was reached through the application of the modified Delphi method. The primary target of these guidelines is adult patients undergoing long-term treatment with NSAIDs, aspirin or other antiplatelet agents and anticoagulants. The revised guidelines reflect the expert consensus and is intended to assist clinicians in the management and prevention of drug-induced peptic ulcer and associated conditions.

[Clinical Guidelines for Drug-induced Peptic Ulcer, 2020 Revised Edition]

The Korean guidelines for nonsteroidal anti-inflammatory drug (NSAID)-induced peptic ulcers were previously developed under co-work with the Korean College of Helicobacter and Upper Gastrointestinal Research and Korean Society of Gastroenterology at 2009. On the other hand, the previous guidelines were based mainly on a literature review and expert opinions. Therefore, the guidelines need to be revised. In this study, a guideline development committee for drug-induced peptic ulcers was organized under the Korean College of Helicobacter and Upper Gastrointestinal Research in 2017. Nine statements were developed, including four for NSAID, three for aspirin and other antiplatelet agents, and two for anticoagulants through de novo processes based on evidence-based medicine, such as a literature search, meta-analysis, and the consensus was established using the modified Delphi method. The primary target of this guideline was adult patients taking long-term NSAIDs, aspirin, or other antiplatelet agent and anticoagulants. The revised guidelines reflect the consensus of expert opinions and are intended to assist relevant clinicians in the management and prevention of drug-induced peptic ulcers and associated conditions.

RNA-sequencing identification and validation of genes differentially expressed in high-risk adenoma, advanced colorectal cancer, and normal controls

Distinct gene expression patterns that occur during the adenoma-carcinoma sequence need to be determined to analyze the underlying mechanism in each step of colorectal cancer progression. Elucidation of biomarkers for colorectal polyps that harbor malignancy potential is important for prevention of colorectal cancer. Here, we use RNA sequencing to determine gene expression profile in patients with high-risk adenoma treated with endoscopic submucosal dissection by comparing with gene expression in patients with advanced colorectal cancer and normal controls. We collected 70 samples, which consisted of 27 colorectal polyps, 24 cancer tissues, and 19 normal colorectal mucosa. RNA sequencing was performed on an Illumina platform to select differentially expressed genes (DEGs) between colorectal polyps and cancer, polyps and controls, and cancer and normal controls. The Kyoto Gene and Genome Encyclopedia (KEGG) and gene ontology (GO) analysis, gene-concept network, GSEA, and a decision tree were used to evaluate the DEGs. We selected the most highly expressed genes in high-risk polyps and validated their expression using real-time PCR and immunohistochemistry. Compared to patients with colorectal cancer, 82 upregulated and 24 downregulated genes were detected in high-risk adenoma. In comparison with normal controls, 33 upregulated and 79 downregulated genes were found in high-risk adenoma. In total, six genes were retrieved as the highest and second highest expressed in advanced polyps and cancers among the three groups. Among the six genes, ANAX3 and CD44 expression in real-time PCR for validation was in good accordance with RNA sequencing. We identified differential expression of mRNAs among high-risk adenoma, advanced colorectal cancer, and normal controls, including that of CD44 and ANXA3, suggesting that this cluster of genes as a marker of high-risk colorectal adenoma.

[Guidelines for Non-variceal Upper Gastrointestinal Bleeding]

Non-variceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB is an important cause for visiting the hospital and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there has been no previous guidelines regarding management of NVUGIB in Korea. Korea is a country with a high prevalence of Helicobacter pylori infection and patients have easy accessibility to receive endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB are mandatory. The Korean Society of Gastroenterology reviewed recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Efficacy and Safety of Rebamipide versus Its New Formulation, AD-203, in Patients with Erosive Gastritis: A Randomized, Double- Blind, Active Control, Noninferiority, Multicenter, Phase 3 Study

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.

Long-term Outcomes of Undifferentiated-Type Early Gastric Cancer with Positive Horizontal Margins after Endoscopic Resection

Background/Aims

This study examined the long-term outcomes of undifferentiated-type early gastric cancer (UD EGC) with positive horizontal margins (HMs) after endoscopic resection (ER) and compared them between additional surgery and nonsurgical management.

Methods

From 2005 to 2015, a total of 1,124 patients with UD EGC underwent ER at 18 tertiary hospitals in Korea. Of them, 92 patients with positive HMs as the only noncurative factor (n=25) or with both positive HMs and tumor size >2 cm (n=67) were included. These patients underwent additional surgery (n=40), underwent additional endoscopic treatment (n=6), or were followed up without further treatment (n=46).

Results

No lymph node (LN) metastasis was found in patients who underwent additional surgery. During a median follow-up of 57.7 months (interquartile range, 27.6 to 68.8 months), no LN or distant metastases or gastric cancer-related deaths occurred in the overall cohort. At baseline, the residual cancer rate was 57.8% (26/45) after additional surgery or ER. The 5-year local recurrence rate was 33.6% among patients who were followed up without additional treatment. The 5-year overall survival rates were 95.0% and 87.8% after additional surgery and nonsurgical management (endoscopic treatment or close follow-up), respectively (log-rank p=0.224). In the multivariate Cox regression analysis, nonsurgical management was not associated with an increased risk of mortality.

Conclusions

UD EGC with positive HMs after ER may have favorable long-term outcomes and a very low risk of LN metastasis. Nonsurgical management may be suggested as an alternative, particularly for patients with old age or chronic illness. (Gut Liver 2021;15-731)

Consistency of Helicobacter pylori eradication rates of first-line concomitant and sequential therapies in Korea: A nationwide multicenter retrospective study for the last 10 years

BACKGROUND

Eradication rate of standard triple therapy for H. pylori has declined to unacceptable level, and alternative regimens such as concomitant and sequential therapy have been introduced. We aimed to assess the consistency of eradication rates of concomitant and sequential therapies as for the first-line H. pylori eradication in Korea.

METHODS

A nationwide multicenter retrospective study was conducted including 18 medical centers from January 2008 to December 2017. We included 3,800 adults who had test to confirm H. pylori eradication within 1 year after concomitant or sequential therapy.

RESULTS

Concomitant and sequential therapy were prescribed for 2508 and 1292 patients, respectively. The overall eradication rate of concomitant therapy was significantly higher than that of sequential therapy (91.8% vs. 86.1%, p < .001). In time trend analysis, the eradication rates of concomitant therapy were 90.2%, 88.2%, 92.1%, 94.3%, 91.1%, and 93.4% for each year from 2012 to 2017 with an increasing trend (p = .0146), while those of ST showed no significant trend (p = .0873). Among 263 patients with second-line therapy, bismuth quadruple therapy showed significantly higher eradication rate than quinolone-based triple therapy (73.9% vs. 51.5% in ITT analysis, p = .001; 82.7% vs. 63.0% in PP analysis, p = .002).

CONCLUSION

Concomitant therapy is the best regimen for the first-line H. pylori eradication showing consistently higher eradication rate with an increasing trend for the last 10 years in Korea. Bismuth quadruple therapy should be considered for second-line therapy after eradication failure using non-bismuth quadruple therapy.

Risk factors of lymph node metastasis after non-curative endoscopic resection of undifferentiated-type early gastric cancer

BACKGROUND

This study aimed to investigate risk factors for lymph node (LN) or distant metastasis after non-curative endoscopic resection (ER) of undifferentiated-type early gastric cancer (EGC).

METHODS

Of 1124 patients who underwent ER for undifferentiated-type gastric cancer at 18 tertiary hospitals across six geographic areas in Korea between 2005 and 2014, 634 with non-curative ER beyond the expanded criteria were retrospectively enrolled. According to the treatment after ER, patients were divided into additional surgery (n = 270) and follow-up (n = 364) groups. The median follow-up duration was 59 months for recurrence and 84 months for mortality.

RESULTS

LN metastasis was found in 6.7% (18/270) of patients at surgery. Ulcer [odds ratio (OR) 3.83; 95% confidence interval (CI) 1.21-12.13; p = 0.022] and submucosal invasion (OR 10.35; 95% CI 1.35-79.48; p = 0.025) were independent risk factors. In the follow-up group, seven patients (1.9%) developed LN or distant recurrence. Ulcer [hazard ratio (HR) 7.60; 95% CI 1.39-35.74; p = 0.018], LVI (HR 6.80; 95% CI 1.07-42.99; p = 0.042), and positive vertical margin (HR 6.71; 95% CI 1.28-35.19; p = 0.024) were independent risk factors. In the overall cohort, LN metastasis rates were 9.6% in patients with two or more risk factors and 1.2% in those with no or one risk factor.

CONCLUSIONS

LVI, ulcer, submucosal invasion, and positive vertical margin are independently associated with LN or distant metastasis after non-curative ER of undifferentiated-type EGC. Surgical resection is strongly recommended for patients with two or more risk factors.

[Helicobacter pylori Eradication in Drug-related Peptic Ulcer]

Non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin are the most frequently prescribed drugs worldwide, and their long-term use often leads to peptic ulcers (PUs) along with serious complications, such as bleeding and perforation. Helicobacter pylori (H. pylori) infection is a significant risk factor for developing NSAID-related PU and ulcer bleeding during long-term aspirin use. In a revised version of the Clinical Guidelines for Drug-induced Peptic Ulcer, two statements regarding H. pylori eradication are recommended. 1) Patients scheduled for long-term NSAID therapy should be tested and treated for H. pylori infection to prevent PU and its complications. 2) Patients with a history of PU receiving long-term low-dose aspirin (LDA) therapy should undergo treatment for H. pylori infection to prevent PU and its complications. On the other hand, unlike NSAID-naïve patients, the preventive effects of H. pylori eradication in chronic NSAID users are unclear. In addition, anti-ulcer drugs, such as proton pump inhibitors, may be necessary for maintenance therapy after H. pylori eradication in a subset of long-term LDA users, particularly if the patients are taking concomitant antiplatelet agents or anticoagulants.

The Role of Acid Suppressants in the Prevention of Anticoagulant-Related Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

Background/Aims

Although acid suppressants are widely used for the prevention or treatment of drug-induced upper gastrointestinal bleeding (GIB), evidence regarding the prevention of anticoagulant-related GIB is scarce. The aim of this study was to evaluate the protective effect of acid suppressants against anticoagulant-related GIB.

Methods

A systematic review was conducted of studies that evaluated the protective effect of acid suppressants against anticoagulant-related GIB found in PubMed, the Cochrane library, Embase, and KoreaMed from the date of database inception to April 2018. Random effect model meta-analyses with sensitivity analyses were conducted. The methodological quality of each included publication was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies. Publication bias was assessed.

Results

In total, six nested case-control or cohort studies were identified and analyzed. Proton-pump inhibitors (PPI) had a protective effect against upper GIB in patients on dicumarinics (risk ratio [RR], 0.56; 95% confidence interval [CI], 0.38 to 0.83; I², 0%); however, the histamine-2 receptor antagonist did not have the same effect (RR, 0.97; 95% CI, 0.52 to 1.81; I², 0%). Acid suppressants did not have a protective effect against GIB in patients on dabigatran (hazard ratio, 0.78; 95% CI, 0.44 to 1.37; I², 81.8%).

Conclusions

The protective effect of PPIs against dicumarinics-related upper GIB was clear, while there was no evidence supporting the protective effect of acid suppressants against dabigatran-related GIB. However, in the absence of randomized trials demonstrating a lack of bias, solid conclusions cannot be drawn.

Guidelines for Nonvariceal Upper Gastrointestinal Bleeding

Nonvariceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB requires hospitalization and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there have been no previous guidelines regarding management of NVUGIB in Korea. Korea has a high prevalence of Helicobacter pylori infections, and patients have easy accessibility to endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB in Korea are essential. The Korean Society of Gastroenterology reviewed the recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Clinicopathological Features of Small Bowel Tumors Diagnosed by Video Capsule Endoscopy and Balloon-Assisted Enteroscopy: A Single Center Experience

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.

Intestinal Epithelial Deletion of Sphk1 Prevents Colitis-Associated Cancer Development by Inhibition of Epithelial STAT3 Activation

BACKGROUND AND AIMS

Colitis-associated cancer (CAC) is one of the most serious complications in patients with inflammatory bowel disease. Sphingosine kinase 1 (Sphk1) is a key enzyme in the sphingolipid pathway and has oncogene potential for inducing both initiation and progression of tumors. The aim of this work is to characterize the role of epithelial Sphk1 in mouse colitis and CAC models.

METHODS

We investigated the roles of Sphk1 in CAC by conditional deletion of Sphk1 in intestinal epithelial cells (IECs).

RESULTS

CAC was induced in both Sphk1^ΔIEC/Apc^Min/+ and Sphk1^IEC/Apc^Min/+ mice by administration of 2% dextran sodium sulfate (DSS) for 7 days. Genetic deletion of Sphk1 significantly reduced the number and size of tumors in Apc^Min/+ mice. Histologic grade was more severe in Sphk1^ΔIEC/Apc^Min/+ mice compared with Sphk1^IEC/Apc^Min/+ mice (invasive carcinoma, 71% versus 13%, p < 0.05). Deletion of Sphk1 decreased mucosal proliferation and inhibited STAT3 activation and genetic expression of cyclin D1 and cMyc in tumor cells. Conditional deletion of Sphk1 using CRISPR-Cas9 in HCT 116 cells inhibited interleukin (IL)-6-mediated STAT3 activation.

CONCLUSIONS

Epithelial conditional deletion of Sphk1 inhibits CAC in Apc^Min/+-DSS models in mice by inhibiting STAT3 activation and its target signaling pathways.

A prospective randomized clinical study evaluating the efficacy and compliance of oral sulfate solution and 2-L ascorbic acid plus polyethylene glycol

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.

CONCLUSION

OSS had a non-inferior bowel cleansing efficacy than AA + PEG regardless of colon segment.

Characteristics of proximal early gastric cancer differentiating distal early gastric cancer

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<0.001), undifferentiated type (38.0 vs. 19.6%, p<0.001), tumor size (29.5 ±19.4 vs. 20.3 ±16.8 mm, p<0.001) and submucosal (SM) invasion (60.9 vs. 25.7%, p<0.001) were significantly higher in the proximal group than in the distal group. In multivariate analysis, the proximal location of EGC was a significant risk factor for SM invasion in the total population (odds ratio [OR], 3.541; 95% confidence interval [CI], 2.053–6.110; p<0.001), and in subgroup with EGC < 30mm (n = 279) (OR, 5.940; 95% CI, 2.974–11.862; p<0.001). In conclusion, careful therapeutic decision of proximal EGC is essential due to the different histopathological characteristics such as large tumor size and higher potential for SM invasion.

Proton pump inhibitor: The dual role in gastric cancer

Proton pump inhibitors (PPIs) are one of the most frequently used medications for upper gastrointestinal diseases. However, a number of physicians have raised concern about the serious side effects of long-term use of PPIs, including the development of gastric cancer. Recent epidemiological studies have reported a significant association between long-term PPI intake and the risk of gastric cancer, even after successful Helicobacter pylori eradication. However, the effects of PPIs on the development of pre-malignant conditions such as atrophic gastritis or intestinal metaplasia are not fully known, suggesting the need for comprehensive and confirmative studies are needed in the future. Meanwhile, several experimental studies have demonstrated the effects of PPIs in reducing chemoresistance in gastric cancer cells by modulating the acidic microenvironment, cancer stemness and signal transducer and activator of transcription 3 (STAT3) signaling pathway. The inhibitory effects of PPIs on STAT3 activity may overcome drug resistance and enhance the efficacy of conventional or targeted chemotherapeutic agents. Taken together, PPIs may “play dual role” in gastric carcinogenesis and treatment of gastric cancer.

Can More Aggressive Treatment Improve Prognosis in Patients with Hepatocellular Carcinoma? A Direct Comparison of the Hong Kong Liver Cancer and Barcelona Clinic Liver Cancer Algorithms

Background/Aims

In 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＜0.001). However, 1-year and 3-year survival were predicted better using the HKLC system than the BCLC system (area under the receiver operating characteristic curve: 0.869 vs 0.856 for 1 year, p=0.002; 0.841 vs 0.827 for 3 years, p=0.010). In hypothetical survival curves, the HKLC system exhibited better median overall survival than the BCLC system (33.1 months vs 19.2 months). In evaluations of prognosis according to either BCLC or HKLC treatment guidelines, risk of death was reduced in the group following only HKLC guidelines compared with the group following only BCLC guidelines (hazard ratio, 0.601; 95% confidence interval, 0.443 to 0.816; p=0.001).

Conclusions

Although both staging systems predicted and discriminated HCC prognoses well, the HKLC system showed more encouraging survival benefits than the BCLC system.

Inhibition of STAT3 in gastric cancer: role of pantoprazole as SHP-1 inducer

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.

Comparison of the Hospital-Acquired Clostridium difficile Infection Risk of Using Proton Pump Inhibitors versus Histamine-2 Receptor Antagonists for Prophylaxis and Treatment of Stress Ulcers: A Systematic Review and Meta-Analysis

Background/Aims

Although proton pump inhibitors (PPIs) have been widely used for the prevention and treatment of stress gastric ulcers in hospital settings, there are concerns that PPIs increase the risk of Clostridium difficile infection (CDI). However, little is known about the risk of CDI following PPI and histamine-2 receptor antagonist (H2RA) use. We evaluated the comparative hospital-acquired CDI occurrence risk associated with the concurrent use of PPIs versus H2RAs.

Methods

A systematic search of PubMed, MEDLINE/Ovid, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and Google Scholar through August 19, 2016, identified 12 studies that reported the hospital-acquired CDI occurrence following H2RA and PPI use for the prevention and treatment of stress gastric ulcers. Random-effects pooled odds ratios and 95% confidence intervals were estimated. Heterogeneity was measured using I², and a meta-regression analysis was conducted. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the overall quality of the evidence.

Results

A total of 74,132 patients from 12 observational studies were analyzed. Compared to H2RAs, PPIs increased the risk of CDI by 38.6% (pooled odds ratio, 1.386; 95% confidence interval, 1.152 to 1.668; p=0.001; I²=42.81%). Subgroup analyses of the purpose of study medication use, study site, and study design confirmed the consistency of a greater CDI risk with PPIs than with H2RAs. The overall quality of evidence was rated as low.

Conclusions

The use of PPIs for both the prevention and treatment of stress ulcers was associated with a 38.6% increased risk of hospital-acquired CDI occurrence compared to H2RA use.

Usefulness of CA 19-9 for pancreatic cancer screening in patients with new-onset diabetes

BACKGROUND

Generally, carbohydrate antigen 19-9 (CA 19-9) is not useful for screening pancreatic cancer in the asymptomatic general population. This study aimed to evaluate the utility of CA 19-9 level as a screening indicator of pancreatic cancer in asymptomatic patients with new-onset diabetes.

METHODS

We retrospectively reviewed the medical records of patients who visited our health promotion center for health check-ups without cancer related symptoms from January 2005 to January 2014, and were newly diagnosed with diabetes mellitus (DM) within 2 years before their visit.

RESULTS

Of the 5111 asymptomatic patients with new-onset DM (<2 years) selected for analyses, 87 (1.7%) eventually developed pancreatic cancer after the health check-up. In the subgroup of 322 patients with high total bilirubin levels (>1.7 mg/dL) at the screening time, 42 (73.7%) of 57 patients with high CA 19-9 levels (>37 IU/mL) had been diagnosed as pancreatic cancer during follow-up period and 12 (4.5%) of 265 patients with normal CA 19-9 levels had finally developed pancreatic cancer (OR = 16.3). In the subgroup of 4789 patients with normal bilirubin levels, pancreatic cancer had been detected in 20 (3.8%) of 522 patients with high CA 19-9 level, while only 13 (0.3%) in 4267 patients with normal CA 19-9 levels (OR = 12.6), respectively.

CONCLUSION

CA 19-9 levels after a diagnosis of new-onset DM could be a useful biomarker of pancreatic cancer, especially in patients with high serum bilirubin.

Arsenic trioxide attenuates STAT-3 activity and epithelial-mesenchymal transition through induction of SHP-1 in gastric cancer cells

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.

Additional Benefits of Routine Drugs on Gastrointestinal Cancer: Statins, Metformin, and Proton Pump Inhibitors

BACKGROUND

Commonly used medications including statins, metformin, and proton pump inhibitors (PPIs) effectively reduce the risk of esophageal, gastric, and colorectal cancer (CRC).

SUMMARY

A number of observational studies and meta-analyses have shown that long-term statin use significantly reduces the incidence of gastrointestinal (GI) cancer. Moreover, statin use after GI cancer diagnosis has been significantly associated with better prognosis in large-scale cohort studies. Metformin was rigorously evaluated in a population-based study and meta-analysis, and was found to have an unexpected benefit in the prevention and prolonged survival of CRC patients with type 2 diabetes mellitus. In contrast, few studies have demonstrated the chemopreventive effect of metformin for esophageal and gastric cancer. Recent observational studies have demonstrated that PPIs effectively reduce the progression of nondysplastic Barrett's esophagus into esophageal adenocarcinoma in a dose-dependent manner. However, the association between chronic PPI use and CRC or gastric cancer risk is still controversial. It was expected that these 3 routinely used medicines would show a synergistic effect with conventional systemic chemotherapy in advanced GI cancers. However, recent phase III studies failed to show significantly better outcomes. Key Messages: Further studies are needed to identify "additional" anticancer effects of these commonly used medicines.

Foods Inducing Typical Gastroesophageal Reflux Disease Symptoms in Korea

Background/Aims

Several specific foods are known to precipitate gastroesophageal reflux disease (GERD) symptoms and GERD patients are usually advised to avoid such foods. However, foods consumed daily are quite variable according to regions, cultures, etc. This study was done to elucidate the food items which induce typical GERD symptoms in Korean patients.

Methods

One hundred and twenty-six Korean patients with weekly typical GERD symptoms were asked to mark all food items that induced typical GERD symptoms from a list containing 152 typical foods consumed daily in Korea. All patients underwent upper gastrointestinal endoscopy followed by 24-hour ambulatory esophageal pH monitoring. The definition of “GERD” was if either of the 2 studies revealed evidence of GERD, and “possible GERD” if both studies were negative.

Results

One hundred and twenty-six cases (51 GERD and 75 possible GERD) were enrolled. In 19 (37.3%) of 51 GERD cases and in 17 (22.7%) of 75 possible GERD cases, foods inducing typical GERD symptoms were identified. In the GERD group (n = 19), frequent symptom-inducers were hot spicy stews, rice cakes, ramen noodles, fried foods, and topokki. In the possible GERD group (n = 17), frequent symptom-inducers were hot spicy stews, fried foods, doughnuts, breads, ramen noodles, coffee, pizza, topokki, rice cakes, champon noodles, and hotdogs.

Conclusions

In one-third of GERD patients, foods inducing typical symptoms were identified. Hot spicy stews, rice cakes, ramen noodles, fried foods, and topokki were the foods frequently inducing typical symptoms in Korea. The list of foods frequently inducing typical GERD symptoms needs to be modified based on their own local experiences.

Therapeutic Outcomes of Endoscopic Resection of Early Gastric Cancer with Undifferentiated-Type Histology: A Korean ESD Registry Database Analysis

Background/Aims

To assess the therapeutic outcomes of endoscopic resection (ER) of early gastric cancer (EGC) with undifferentiated-type histology.

Methods

Cases of ER of EGC with undifferentiated-type histology in the Korean endoscopic submucosal dissection (ESD) registry database were identified and reviewed. The immediate outcomes, including en bloc resection, complete resection, and curative resection rates, and long-term outcomes, including recurrence and survival rates, were extracted and analyzed.

Results

From 2006 to 2015, 275 EGCs with undifferentiated-type histology from 275 patients were identified. The immediate outcomes were as follows: en bloc resection rate: 92.4%; complete resection rate: 80%; and curative resection rate: 36.4%. Compared to patients with lesions that were beyond the expanded indication, those with expanded indication lesions showed better therapeutic outcomes. There was no difference in immediate outcomes between patients with poorly differentiated adenocarcinoma (PDC) and signet ring cell carcinoma (SRC). However, compared to ER of SRC, ER of PDC had a stronger association with submucosal invasion (41.9% vs. 23.6%, p=0.003). With regard to long-term outcomes, there was no difference between lesions with curative and non-curative resections in the recurrence and mortality rates. These rates also did not differ between PDC and SRC (median follow up: 3.96 years).

Conclusions

ER confined to expanded indication lesions can be considered for treatment of EGC with undifferentiated-type histology.

Astaxanthin Inhibits Proliferation of Human Gastric Cancer Cell Lines by Interrupting Cell Cycle Progression

Background/Aims

Astaxanthin 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 p27^kip-1 increased the KATO-III and SNU-1 cell lines in an astaxanthin dose-dependent manner.

Conclusions

Astaxanthin 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 p27^kip-1.

Effect of arsenic trioxide on epithelial-mesenchymal transition via induction of SH2?containing protein tyrosine phosphatase 1

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Background: Arsenic trioxide (ATO) is known to inhibit epithelial-mesenchymal transition (EMT) in hepatolocellular carcinoma and breast cancer cells, however, little has been reported in gastric cancer cells. In this study, we aimed to investigate the mechanism of ATO to inhibit signal transducer and activator of transcription 3 (STAT3) activity and EMT in gastric cancer cells. Methods: We performed wound closure assay and Matrigel invasion assay for functional studies of EMT, and western blot for measurement of protein markers using AGS gastric cancer cells. Results: Compared with control, 5 and 10 μM of ATO significantly inhibited cellular migration and inhibition in a dose-dependent manner. Furthermore, ATO significantly downregulated snail expression, a mesenchymal marker, and upregulated E-cadherin expression, an epithelial marker. We could observe that ATO induced SH2-containing protein tyrosine phosphatase 1 (SHP1), a non-receptor type protein tyrosine phosphatase, and subsequently downregulated phospho-STAT3 in a dose-dependent manner. To validate the molecular link between ATO and SHP1 to inhibit EMT in gastric cancer cell, we pre-treated 50 μM of pervanadate, a phosphatase inhibitor, before treatment of 10 μM ATO, and this significantly abolished anti-invasive effect by ATO in AGS cells. In xenograft tumor model, intraperitoneal injection of ATO significantly reduced the tumor volume and upregulated SHP-1 expression by immunohistochemistry stain compared with vehicle, which were reversed by ATO with pervanadate injection. Conclusions: Our findings suggest that ATO may show anti-EMT effects via induction of SHP1 and inhibition of STAT3 activity in gastric cancer cells.

[Inverted Hyperplastic Polyp in Stomach: A Case Report and Literature Review]

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.

Endoscopic Approach for Major Complications of Bariatric Surgery

As lifestyle and diet patterns have become westernized in East Asia, the prevalence of obesity has rapidly increased. Bariatric surgeries, such as Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and laparoscopic adjustable gastric banding (LAGB), are considered the first-line treatment option in patients with severe obesity. However, postoperative complications have increased and the proper management of these complications, including the use of endoscopic procedures, has become important. The most serious complications, such as leaks and fistulas, can be treated with endoscopic stent placement and injection of fibrin glue, and a novel full-thickness closure over-the-scope clip (OTSC) has been used for treatment of postoperative leaks. Stricture at the gastrojejunal (GJ) anastomosis site after RYGB or incisura angularis in SG can be managed using stents or endoscopic balloon dilation. Dilation of the GJ anastomosis or gastric pouch may lead to failure of weight loss, and the use of endoscopic sclerotherapy, novel endoscopic suturing devices, and OTSCs have been attempted. Intragastric migration of the gastric band can be successfully treated using various endoscopic tools. Endoscopy plays a pivotal role in the management of post-bariatric complications, and close cooperation between endoscopists and bariatric surgeons may further increase the success rate of endoscopic procedures.

Impact of homeobox genes in gastrointestinal cancer

Homeobox genes, including HOX and non-HOX genes, have been identified to be expressed aberrantly in solid tumors. In gastrointestinal (GI) cancers, most studies have focused on the function of non-HOX genes including caudal-related homeobox transcription factor 1 (CDX1) and CDX2. CDX2 is a crucial factor in the development of pre-cancerous lesions such as Barrett’s esophagus or intestinal metaplasia in the stomach, and its tumor suppressive role has been investigated in colorectal cancers. Recently, several HOX genes were reported to have specific roles in GI cancers; for example, HOXA13 in esophageal squamous cell cancer and HOXB7 in stomach and colorectal cancers. HOXD10 is upregulated in colorectal cancer while it is silenced epigenetically in gastric cancer. Thus, it is essential to examine the differential expression pattern of various homeobox genes in specific tumor types or cell lineages, and understand their underlying mechanisms. In this review, we summarize the available research on homeobox genes and present their potential value for the prediction of prognosis in GI cancers.

The roles of HOXB7 in promoting migration, invasion, and anti-apoptosis in gastric cancer

BACKGROUND AND AIM

The aim of this study was to compare HOXB7 expression level between gastric cancer and non-cancerous gastric tissues. Additionally, the functional effects of HOXB7, including its pro-migration or invasion and anti-apoptosis roles, were evaluated in gastric cancer cells.

METHODS

Both gene and protein expression levels of HOXB7 were examined in gastric cancer cell lines, and HOXB7 expression was compared between primary or metastatic gastric cancer tissues and chronic gastritis or intestinal metaplasia tissues. Functional studies included a wound healing assay, a Matrigel invasion assay, and an Annexin-V assay were performed, and Akt/PTEN activity was measured by western blotting.

RESULTS

Both gene and protein expression levels of HOXB7 could be clearly detected in various gastric cancer cell lines except MKN-28 cell. HOXB7 expression was significantly higher in primary or metastatic gastric cancer tissues than in chronic gastritis or intestinal metaplasia tissues. HOXB7 knockdown led to inhibition of cell invasion and migration, had an apoptotic effect, downregulated phosphor-Akt, and upregulated PTEN in AGS and SNU-638 cells. Reinforced expression of HOXB7 caused the opposite effects in MKN-28 and MKN-45 cells.

CONCLUSION

Our study suggests that HOXB7 has an oncogenic role in gastric cancer, which might be related to the modulation of Akt/PTEN activity to induce cell migration/invasion and anti-apoptotic effects.