Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Background: Healthcare-associated infections impose a significant burden on antibiotic usage, healthcare expenditures, and morbidity. Therefore, it is crucial to revise policies to minimize such losses. This nationwide survey aimed to evaluate infection prevention and control (IPC) components in healthcare facilities and encourage improvements in acute care hospitals with inadequate infection prevention settings. This study aims to enhance the infection control capabilities of healthcare facilities. Methods: From December 27, 2021, to May 13, 2022, we conducted a survey of 1,767 acute care hospitals in the Republic of Korea. A survey was conducted to evaluate the infection control components in 1,767 acute care hospitals. Infection control officers provided direct responses to a systematically developed questionnaire. Subsequently, 10% of the respondents were randomly selected for the site investigation. Results: Overall, 1,197 (67.7%) hospitals responded to the online survey. On-site investigations were conducted at 125 hospitals. Hospitals with ≥ 150 beds are advised to have an IPC team under Article 3 of the Medical Service Act; however, only 87.0% (598/687) of hospitals with ≥ 100 beds had one. Conversely, 22.7% (116/510) of hospitals with < 100 beds had an IPC team. Regulations for hand hygiene, waste management, healthcare worker protection and safety, environmental cleaning, standard precautions, and prevention of the transmission of multidrug-resistant pathogens were present in 84.2%, 80.1%, 77.4%, 76.2%, 75.8%, and 63.5% of the hospitals, respectively. Hospitals with < 100 beds had low availability of all categories of standard operating procedures. Conclusion This study is the first national survey of acute care hospitals in the Republic of Korea. The data presented in the current study will improve the understanding of IPC status and will help establish a survey system. Our survey provides a basis for improving policies related to IPC in healthcare facilities.

Background: Although an appropriate weight management strategy is essential for obese individuals, weight loss can have adverse effects on bone mineral density (BMD). We conducted a systematic review of randomized controlled trials to evaluate changes in BMD after the implementation of various weight loss strategies. Methods: The PubMed, Embase, Web of Science, and Cochrane Library databases were searched to find articles published from database inception until June 2023. Randomized controlled trials of various treatments for obese patients that reported changes in BMD were selected. The primary outcome was BMD of the whole body, lumbar spine, and total hip, measured using dual X-ray absorptiometry. Results: Eighteen randomized controlled trials involving 2,510 participants with obesity were included in the analysis. At follow-up examination, the BMD of the lumbar spine decreased significantly after metabolic surgery (mean difference [MD]= –0.40 g/cm2 ; 95% confidence interval [CI], –0.73 to –0.07; I2 = 0%); lifestyle and pharmacological interventions did not result in a significant decrease in BMD at any location. Metabolic surgery also produced the most substantial difference in weight, with an MD of –3.14 (95% CI, –3.82 to –2.47). Conclusion This meta-analysis is the first to examine the effects of all categories of anti-obesity strategies, including the use of anti-obesity medications, on BMD. Bariatric metabolic surgery can have adverse effects on BMD. Moreover, medications can be used as a treatment for weight loss without compromising bone quality.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Background/Aims: Cytomegalovirus (CMV) disease in the upper gastrointestinal (UGI) tract frequently occurs in immunocompromised patients. However, data regarding UGI CMV disease in non-transplant patients compared with those in transplant recipients are limited. Therefore, we compared the clinical characteristics, endoscopic findings, and outcomes of UGI CMV disease in non-transplant patients with those in transplant recipients. Methods: We reviewed the medical records of patients diagnosed with UGI CMV disease between May 1999 and January 2022. UGI CMV disease was defined as symptoms or signs of gastrointestinal disease with typical findings of CMV inclusion body and positive immunochemistry stain or CMV polymerase chain reaction from the endoscopic biopsy specimen. Results: Among the 219 eligible patients, 132 (60.3%) were transplant patients. Age, male sex, and Charlson Comorbidity Index were significantly higher in the non-transplant group than in the transplant group. The most common symptoms were pain and odynophagia (43.8%). Transplant recipients more frequently experienced UGI CMV disease in the stomach than non-transplant patients, typically presenting as erosions or mucosal hyperemia. However, non-transplant patients more commonly experienced UGI CMV disease in the esophagus than transplant recipients, typically presenting as ulcers. The transplant group had a significantly higher clinical response than the non-transplant group. Conclusions UGI CMV disease in transplant patients can be present in the stomach in various forms, including ulcers or erosions. In transplant patients suspected of UGI CMV disease, conducting an esophagogastroduodenoscopy with tissue biopsy in any area where even the slightest mucosal abnormality is observed is essential to facilitate a prompt diagnosis.

Background: Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. Methods: We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition. Results: Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways. Conclusion We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.

Background/Aims: Cytomegalovirus (CMV) disease in the upper gastrointestinal (UGI) tract frequently occurs in immunocompromised patients. However, data regarding UGI CMV disease in non-transplant patients compared with those in transplant recipients are limited. Therefore, we compared the clinical characteristics, endoscopic findings, and outcomes of UGI CMV disease in non-transplant patients with those in transplant recipients. Methods: We reviewed the medical records of patients diagnosed with UGI CMV disease between May 1999 and January 2022. UGI CMV disease was defined as symptoms or signs of gastrointestinal disease with typical findings of CMV inclusion body and positive immunochemistry stain or CMV polymerase chain reaction from the endoscopic biopsy specimen. Results: Among the 219 eligible patients, 132 (60.3%) were transplant patients. Age, male sex, and Charlson Comorbidity Index were significantly higher in the non-transplant group than in the transplant group. The most common symptoms were pain and odynophagia (43.8%). Transplant recipients more frequently experienced UGI CMV disease in the stomach than non-transplant patients, typically presenting as erosions or mucosal hyperemia. However, non-transplant patients more commonly experienced UGI CMV disease in the esophagus than transplant recipients, typically presenting as ulcers. The transplant group had a significantly higher clinical response than the non-transplant group. Conclusions UGI CMV disease in transplant patients can be present in the stomach in various forms, including ulcers or erosions. In transplant patients suspected of UGI CMV disease, conducting an esophagogastroduodenoscopy with tissue biopsy in any area where even the slightest mucosal abnormality is observed is essential to facilitate a prompt diagnosis.

Background: Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. Methods: We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition. Results: Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways. Conclusion We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.

Background: Remimazolam is a novel short-acting benzodiazepine. This study compared the effects of remimazolam and propofol on cognitive function in adult patients after surgery or other procedures. Methods: We searched electronic databases, including PubMed, Embase, CENTRAL, Web of Science, and Scopus, for relevant studies. The primary outcome was the proportion of participants who experienced delirium or impaired cognitive function postoperatively. Secondary outcomes included the incidence of hypotension, bradycardia, and postoperative nausea and vomiting. We estimated the odds ratios (OR) and mean differences (MD) with 95% CIs using a random-effects model. Results: In total, 1295 patients from 11 randomized controlled trials were included. The incidence of postoperative delirium was 8.0% in the remimazolam group and 10.4% in the propofol group that was not significantly different (OR: 0.74, 95% CI [0.39–1.42], P = 0.369, I2 = 32%). More favorable cognitive function, as assessed using the Mini-Mental State Examination, was observed in the remimazolam group compared to the propofol group (MD: 1.06, 95% CI [0.32–1.80], P = 0.005, I2 = 89%). Remimazolam lowered the incidence of hypotension (OR: 0.28, 95% CI [0.21–0.37], P = 0.000, I2 = 0%) compared to propofol. Conclusions Remimazolam did not increase the risk of postoperative delirium and maintained cognitive function well, providing hemodynamic stability during surgery compared to propofol.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.