Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Background and Objectives: The K-ELUVIA study aimed to investigate the clinical effectiveness and safety of Eluvia™, a polymer-coated, paclitaxel-eluting stent, for femoropopliteal artery disease using data from a prospective Korean multicenter registry. Methods: A total of 105 patients with femoropopliteal artery disease who received endovascular treatment (EVT) with Eluvia™ stents at 7 Korean sites were enrolled in a prospective cohort and followed for 2 years. The primary endpoint was the 2-year clinical patency. The secondary endpoint was 2-year freedom from clinically driven target lesion revascularization (TLR). Results: Mean patient age was 68.2±10.4 years, and most patients (82.7%) were male. Mean lesion length was 168.3±117.6 mm. Chronic total occlusion was found in 57.7% of patients.Trans-Atlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) type C or D lesions were present in 46.1% of patients. Procedural success was achieved in 99.0% of patients. The clinical patency rate was 84.4% at 1 year after EVT and 76.3% at 2 years post-EVT. The freedom from TLR rate was 89.1% at 1 year after EVT and 79.1% at 2 years post-EVT. Chronic total occlusion (hazard ratio [HR], 3.53; 95% confidence interval [CI], 1.08–11.67; p=0.039) and smaller mean stent diameter (HR, 0.40; 95% CI, 0.16– 0.98; p=0.044) were identified as independent predictors of loss of clinical patency at 2 years. Conclusions The K-ELUVIA study demonstrated favorable 2-year clinical effectiveness and safety outcomes of Eluvia stent for femoropopliteal artery lesions in real-world practice.

Background and Objectives: The K-ELUVIA study aimed to investigate the clinical effectiveness and safety of Eluvia™, a polymer-coated, paclitaxel-eluting stent, for femoropopliteal artery disease using data from a prospective Korean multicenter registry. Methods: A total of 105 patients with femoropopliteal artery disease who received endovascular treatment (EVT) with Eluvia™ stents at 7 Korean sites were enrolled in a prospective cohort and followed for 2 years. The primary endpoint was the 2-year clinical patency. The secondary endpoint was 2-year freedom from clinically driven target lesion revascularization (TLR). Results: Mean patient age was 68.2±10.4 years, and most patients (82.7%) were male. Mean lesion length was 168.3±117.6 mm. Chronic total occlusion was found in 57.7% of patients.Trans-Atlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) type C or D lesions were present in 46.1% of patients. Procedural success was achieved in 99.0% of patients. The clinical patency rate was 84.4% at 1 year after EVT and 76.3% at 2 years post-EVT. The freedom from TLR rate was 89.1% at 1 year after EVT and 79.1% at 2 years post-EVT. Chronic total occlusion (hazard ratio [HR], 3.53; 95% confidence interval [CI], 1.08–11.67; p=0.039) and smaller mean stent diameter (HR, 0.40; 95% CI, 0.16– 0.98; p=0.044) were identified as independent predictors of loss of clinical patency at 2 years. Conclusions The K-ELUVIA study demonstrated favorable 2-year clinical effectiveness and safety outcomes of Eluvia stent for femoropopliteal artery lesions in real-world practice.

Background and Objectives: The K-ELUVIA study aimed to investigate the clinical effectiveness and safety of Eluvia™, a polymer-coated, paclitaxel-eluting stent, for femoropopliteal artery disease using data from a prospective Korean multicenter registry. Methods: A total of 105 patients with femoropopliteal artery disease who received endovascular treatment (EVT) with Eluvia™ stents at 7 Korean sites were enrolled in a prospective cohort and followed for 2 years. The primary endpoint was the 2-year clinical patency. The secondary endpoint was 2-year freedom from clinically driven target lesion revascularization (TLR). Results: Mean patient age was 68.2±10.4 years, and most patients (82.7%) were male. Mean lesion length was 168.3±117.6 mm. Chronic total occlusion was found in 57.7% of patients.Trans-Atlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) type C or D lesions were present in 46.1% of patients. Procedural success was achieved in 99.0% of patients. The clinical patency rate was 84.4% at 1 year after EVT and 76.3% at 2 years post-EVT. The freedom from TLR rate was 89.1% at 1 year after EVT and 79.1% at 2 years post-EVT. Chronic total occlusion (hazard ratio [HR], 3.53; 95% confidence interval [CI], 1.08–11.67; p=0.039) and smaller mean stent diameter (HR, 0.40; 95% CI, 0.16– 0.98; p=0.044) were identified as independent predictors of loss of clinical patency at 2 years. Conclusions The K-ELUVIA study demonstrated favorable 2-year clinical effectiveness and safety outcomes of Eluvia stent for femoropopliteal artery lesions in real-world practice.

People with obesity maintain low levels of inflammation; therefore, their exposure to foreign antigens can trigger an excessive immune response. In people with obesity or allergic contact dermatitis (ACD), symptoms are exacerbated by a reduction in the number of regulatory T cells (Tregs) and IL-10/TGF-β–modified macrophages (M2 macrophages) at the inflammatory site. Benefits of intermittent fasting (IF) have been demonstrated for many diseases; however, the immune responses regulated by macrophages and CD4+ T cells in obese ACD animal models are poorly understood. Therefore, we investigated whether IF suppresses inflammatory responses and upregulates the generation of Tregs and M2 macrophages in experimental ACD animal models of obese mice. The IF regimen relieved various ACD symptoms in inflamed and adipose tissues. We showed that the IF regimen upregulates Treg generation in a TGF-β-dependent manner and induces CD4+ T cell hypo-responsiveness. IF-M2 macrophages, which strongly express TGF-β and inhibit CD4+ T cell proliferation, directly regulated Treg differentiation from CD4+ T cells. These results indicate that the IF regimen enhances the TGF-β-producing ability of M2 macrophages and that the development of Tregs keeps mice healthy against ACD exacerbated by obesity. Therefore, the IF regimen may ameliorate inflammatory immune disorders caused by obesity.

Purpose: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors have greatly improved survival in EGFR-mutant (EGFRm) non–small cell lung cancer (NSCLC); however, their effects on the tumor microenvironment (TME) are unknown. We assessed the changes induced by neoadjuvant erlotinib therapy (NE) in the TME of operable EGFRm NSCLC. Materials and Methods: This was a single-arm phase II trial for neoadjuvant/adjuvant erlotinib therapy in patients with stage II/IIIA EGFRm NSCLC (EGFR exon 19 deletion or L858R mutations). Patients received up to 2 cycles of NE (150 mg/day) for 4 weeks, followed by surgery and adjuvant erlotinib or vinorelbine plus cisplatin therapy depending on observed NE response. TME changes were assessed based on gene expression analysis and mutation profiling. Results: A total of 26 patients were enrolled; the median age was 61, 69% were female, 88% were stage IIIA, and 62% had L858R mutation. Among 25 patients who received NE, the objective response rate was 72% (95% confidence interval [CI], 52.4 to 85.7). The median disease-free and overall survival (OS) were 17.9 (95% CI, 10.5 to 25.4) and 84.7 months (95% CI, 49.7 to 119.8), respectively. Gene set enrichment analysis in resected tissues revealed upregulation of interleukin, complement, cytokine, transforming growth factor β, and hedgehog pathways. Patients with upregulated pathogen defense, interleukins, and T-cell function pathways at baseline exhibited partial response to NE and longer OS. Patients with upregulated cell cycle pathways at baseline exhibited stable/progressive disease after NE and shorter OS. Conclusion NE modulated the TME in EGFRm NSCLC. Upregulation of immune-related pathways was associated with better outcomes.

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

Purpose: Advances in chemotherapeutic and targeted agents have increased pathologic complete response (pCR) rates after neoadjuvant systemic therapy (NST). Vacuum-assisted biopsy (VAB) has been suggested to accurately evaluate pCR. This study aims to confirm the non-inferiority of the 5-year disease-free survival of patients who omitted breast surgery when predicted to have a pCR based on breast magnetic resonance imaging (MRI) and VAB after NST, compared with patients with a pCR who had undergone breast surgery in previous studies. Methods The Omission of breast surgery for PredicTed pCR patients wIth MRI and vacuumassisted bIopsy in breaST cancer after neoadjuvant systemic therapy (OPTIMIST) trial is a prospective, multicenter, single-arm, non-inferiority study enrolling in 17 tertiary care hospitals in the Republic of Korea. Eligible patients must have a clip marker placed in the tumor and meet the MRI criteria suggesting complete clinical response (post-NST MRI size ≤ 1 cm and lesion-to-background signal enhancement ratio ≤ 1.6) after NST. Patients will undergo VAB, and breast surgery will be omitted for those with no residual tumor. Axillary surgery can also be omitted if the patient was clinically node-negative before and after NST and met the stringent criteria of MRI size ≤ 0.5 cm. Survival and efficacy outcomes are evaluated over five years.Discussion: This study seeks to establish evidence for the safe omission of breast surgery in exceptional responders to NST while minimizing patient burden. The trial will address concerns about potential undertreatment due to false-negative results and recurrence as well as improved patient-reported quality of life issues from the omission of surgery. Successful completion of this trial may reshape clinical practice for certain breast cancer subtypes and lead to a safe and less invasive approach for selected patients.

Background: A decline in masticatory function may indicate brain dysfunction related to dementia, but the relationship between masticatory function and dementia risk remains unclear. This study aimed to investigate whether masticatory function is associated with the risk of cognitive decline and dementia. Methods: Data were obtained from the nationwide prospective cohort study of randomly sampled community-dwelling Koreans aged ≥ 60 years. The 5,064 non-demented participants, whose number of chewing cycles per bite was assessed by clinical interview, were followed for 8 years with biennial assessments of cognitive performance and clinical diagnoses of all-cause dementia and Alzheimer’s disease (AD). Structural brain magnetic resonance imaging was collected from a subset of cohort participants and their spouses for imaging analyses. Results: Males who chewed ≥ 30 cycles/bite had faster decline in global cognition and memory function and were at higher risk for incident all-cause dementia (hazard ratio [HR], 2.91; 95% confidence interval [CI], 1.18–7.18) and AD (HR, 3.22; 95% CI, 1.14–9.11) compared to males with less than 10 cycles/bite. Additionally, increased chewing cycles in males were associated with reduced brain volume, particularly in regions involved in compensatory cognitive control of mastication. There was no significant association between chewing cycles and the risk of dementia or brain volume in females. Conclusion Older men who frequently chew their meals could be considered a notable population at risk for dementia who should be carefully assessed for their cognitive trajectories.