Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Functional dyspepsia (FD) is a chronic upper gastrointestinal (GI) symptom complex that routine diagnostic work-up, such as endoscopy, blood laboratory analysis, or radiological examination, fails to identify a cause. It is highly prevalent in the World population, and its response to the various available therapeutic strategies is only modest because of the heterogenous nature of its pathogenesis. Therefore, FD represents a heavy medical burden for healthcare systems. We constituted a guideline development committee to review the existing guidelines on the management of functional dyspepsia. This committee drafted statements and conducted a systematic review and meta-analysis of various studies, guidelines, and randomized control trials. External review was also conducted by selected experts. These clinical practice guidelines for FD were developed based on evidence recently accumulated with the revised version of FD guidelines released in 2011 by the Korean Society of Neurogastroenterology and Motility. These guidelines apply to adults with chronic symptoms of FD and include the diagnostic role of endoscopy, Helicobacter pylori screening, and systematic review and meta-analyses of the various treatment options for FD (proton pump inhibitors, H. pylori eradication, and tricyclic antidepressants), especially according to the FD subtype. The purpose of these new guidelines is to aid the understanding, diagnosis, and treatment of FD, and the targets of the guidelines are clinicians, healthcare workers at the forefront of patient care, patients, and medical students. The guidelines will continue to be revised and updated periodically. (J Neurogastroenterol Motil 2020;26:29-50)

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Background The pathogenesis and clinicopathologic characteristics of Epstein-Barr virus (EBV)-negative lymphoepithelioma-like gastric carcinoma (LELC) are still unclear. In addition, it remains controversial whether EBV infection itself affects the prognosis of LELC. Methods Between 1995 and 2011, 145 LELC patients (124 patients with EBV infection and 21 patients without EBV infection) underwent radical gastrectomy with D2 lymph node dissection. The clinicopathologic features and prognosis of EBV-negative LELC cases were compared with those of EBV-positive LELC cases. The median duration of follow-up after surgery was 55 months. Microsatellite instability (MSI) analysis was performed on 20 EBV-negative LELC cases. Results EBV-negative LELC accounted for 14.5 % of the total LELC cases. EBV-negative LELC was significantly associated with older age, female sex, advanced T stage, and advanced American Joint Committee on Cancer (AJCC) tumor stage compared with EBV-positive LELC. In univariate analysis, patients with EBV-negative LELC had significantly shorter overall, disease-specific, and recurrencefree survival than those with EBV-positive LELC. The 5-year overall survival rates were 81.0 % for patients with EBVnegative LELC and 96.2 % for patients with EBV-positive LELC. In a Cox proportional hazards model, EBV infection, age, and AJCC tumor stage were identified as independent predictors of overall survival. MSI-high, MSI-low, and microsatellite-stable tumors accounted for 25, 10, and 65 % of EBV-negative LELC cases, respectively. MSI status did not affect the prognosis of EBV-negative LELC cases. Conclusions EBV infection serves as an independent predictor of survival in patients with LELC. EBV-negative LELC exhibited clinicopathologic features and prognosis distinct from those of EBV-positive LELC.

BackgroundThe eradication rate of Helicobacter pylori (H. pylori) with triple therapy which was considered as standard first-line treatment has decreased to 70–85%. The aim of this study is to compare 7-day triple therapy versus 10-day sequential therapy as the first line treatment.MethodsData of 1240 H. pylori positive patients treated with triple therapy or sequential therapy from January 2013 to December 2015 were analyzed retrospectively. The patients who had undertaken previous H. pylori eradication therapy or gastric surgery were excluded.ResultsThere were 872 (74.3%) patients in the triple therapy group, and 302 (25.7%) patients in the sequential therapy group. There was no significant difference between the two groups regarding age, residence, comorbidities or drug compliance, but several differences were noted in endoscopic characteristics and indication for the treatment. The eradication rate of H. pylori by intention to treat analysis was 64.3% in the triple therapy group, and 81.9% in the sequential therapy group (P = 0.001). In per protocol analysis, H. pylori eradication rate in the triple therapy and sequential therapy group was 81.9 and 90.3%, respectively (P = 0.002). There was no significant difference in overall adverse events between the two groups (P = 0.706). For the rescue therapy, bismuth-containing quadruple therapy showed comparable treatment efficacy after sequential therapy, as following triple therapy.ConclusionsThe eradication rate of triple therapy was below the recommended threshold. Sequential therapy could be effective and tolerable candidate for the first-line H. pylori eradication therapy.