Purpose: Rare diseases occur in <50 per 100000 people and require lifelong management. However, essential epidemiological data on such diseases are lacking, and a consecutive monitoring system across time and regions remains to be established. Standardized digital phenotypes are required to leverage an international data network for research on rare endocrine diseases. We developed digital phenotypes for rare endocrine diseases using the observational medical outcome partnership common data model. Materials and Methods: Digital phenotypes of three rare endocrine diseases (medullary thyroid cancer, hypoparathyroidism, pheochromocytoma/paraganglioma) were validated across three databases that use different vocabularies: Severance Hospital’s electronic health record from South Korea; IQVIA’s United Kingdom (UK) database for general practitioners; and IQVIA’s United States (US) hospital database for general hospitals. We estimated the performance of different digital phenotyping methods based on International Classification of Diseases (ICD)-10 in the UK and the US or systematized nomenclature of medicine clinical terms (SNOMED CT) in Korea. Results: The positive predictive value of digital phenotyping was higher using SNOMED CT-based phenotyping than ICD-10-based phenotyping for all three diseases in Korea (e.g., pheochromocytoma/paraganglioma: ICD-10, 58%–62%; SNOMED CT, 89%). Estimated incidence rates by digital phenotyping were as follows: medullary thyroid cancer, 0.34–2.07 (Korea), 0.13–0.30 (US); hypoparathyroidism, 0.40–1.20 (Korea), 0.59–1.01 (US), 0.00–1.78 (UK); and pheochromocytoma/paraganglioma, 0.95–1.67 (Korea), 0.35–0.77 (US), 0.00–0.49 (UK). Conclusion Our findings demonstrate the feasibility of developing digital phenotyping of rare endocrine diseases and highlight the importance of implementing SNOMED CT in routine clinical practice to provide granularity for research.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Background/Aims: Post-infectious irritable bowel syndrome (PI-IBS) is characterized by chronic gastrointestinal symptoms that arise following an episode of infectious enteritis. The incidence rates vary, ranging from 5% to 32% and the risk factors are not well known. We aim to investigate the incidence and risk factors of PI-IBS in enteritis patients admitted to university hospitals in Korea. Methods: This multi-center prospective study was conducted in patients hospitalized for infectious enteritis. Each patient underwent 1 outpatient visit and 3 telephone surveys during the first year after discharge to determine if PI-IBS occurred within the follow-up period. Results: In the 3-month survey, 7 out of 354 patients (2%) were diagnosed with PI-IBS, and after 1 year, only 1 patient met the criteria for IBS.No statistically significant difference was found between the PI-IBS group and the non-PI-IBS group in terms of age, sex, underlying diseases, medication history, gastrointestinal symptoms, enteritis location, causative strain, hospitalization and treatment periods, and laboratory findings. Female sex (P = 0.003), enteropathogenic Escherichia coli (EPEC) infection (P = 0.044), and a longer total treatment period (P = 0.018) were independent risk factors for diarrhea lasting ≥ 3 months after enteritis. Conclusions The incidence of PI-IBS in Korea was relatively low, and most cases improved over time. No risk factors associated with the development of PI-IBS were found. However, persistent diarrhea after enteritis was associated with female sex, EPEC infection, and severe or long-lasting enteritis. IBS symptoms may persist after severe enteritis but usually improve with time.

Background: The novel sodium-glucose cotransporter-2 (SGLT2) inhibitor enavogliflozin effectively lowers glycosylated hemoglobin levels and body weights without the increased risk of serious adverse events; however, the long-term clinical benefits of enavogliflozin in terms of cardiovascular and renal outcomes have not been investigated. Methods: This study is an investigator-initiated, multicenter, randomized, pragmatic, open-label, active-controlled, non-inferiority trial. Eligible participants are adults (aged ≥19 years) with type 2 diabetes mellitus (T2DM) who have a history of, or are at risk of, cardiovascular disease. A total of 2,862 participants will be randomly assigned to receive either enavogliflozin or other SGLT2 inhibitors with proven cardiorenal benefits, such as dapagliflozin or empagliflozin. The primary endpoint is the time to the first occurrence of a composite of major adverse cardiovascular or renal events (Clinical Research Information Service registration number: KCT0009243). Conclusion This trial will determine whether enavogliflozin is non-inferior to dapagliflozin or empagliflozin in terms of cardiorenal outcomes in patients with T2DM and cardiovascular risk factors. This study will elucidate the role of enavogliflozin in preventing vascular complications in patients with T2DM.

Background: Antithyroid drug (ATD) treatment is the preferred initial treatment for Graves’ disease (GD) in South Korea, despite higher treatment failure rates than radioactive iodine (RAI) therapy or thyroidectomy. This study aimed to evaluate the incidence of treatment failure associated with the primary modalities for GD treatment in real-world practice. Methods: We included 452,001 patients diagnosed with GD between 2004 and 2020 from the Korean National Health Insurance Service-National Health Information Database. Treatment failure was defined as switching from ATD, RAI, or thyroidectomy treatments, and for ATD specifically, inability to discontinue medication for over 2 years. Results: Mean age was 46.2 years, with females constituting 70.8%. Initial treatments for GD included ATDs (98.0%), thyroidectomy (1.3%), and RAI (0.7%), with a noted increment in ATD application from 96.2% in 2004 to 98.8% in 2020. During a median follow- up of 8.5 years, the treatment failure rates were 58.5% for ATDs, 21.3% for RAI, and 2.1% for thyroidectomy. Multivariate analysis indicated that the hazard ratio for treatment failure with ATD was 2.81 times higher than RAI. RAI treatments ≥10 mCi had 37% lower failure rates than doses <10 mCi. Conclusion ATDs are the most commonly used for GD in South Korea, followed by thyroidectomy and RAI. Although the risk of treatment failure for ATD is higher than that of RAI therapy, initial RAI treatment in South Korea is relatively limited compared to that in Western countries. Further studies are required to evaluate the cause of low initial RAI treatment rates in South Korea.

Background/Aims: Small bowel capsule endoscopy (SBCE) has become the standard for initial evaluation in the diagnosis of small bowel lesions. Although optimal visualization of the mucosa is important, patients experience difficulty in consuming a large volume of bowel preparation agents. This study aimed to compare the efficacy and safety of 1-L polyethylene glycol (PEG) with ascorbic acid (AA) and 2-L PEG with AA. Methods: In this prospective, multicenter, non-inferiority study, patients who received SBCE were randomly assigned to consume 1-L PEG with AA or 2-L PEG with AA for small bowel preparation. The primary outcome was adequate small bowel visibility quality (SBVQ). The secondary outcomes included diagnostic yield, cecal complete rate, and adverse events. Results: One hundred and forty patients were enrolled in this study, 70 patients per group. In the per-protocol analysis, there were no significant differences in the adequate SBVQ rate (94.0% vs 94.3%; risk difference, –0.3; 95% confidence interval, –8.1 to 7.6; p=1.000), diagnostic yield rate (49.3% vs 48.6%, p=0.936), or cecal complete rate (88.1% vs 92.9%, p=0.338) between the 1-L PEG with AA group and 2-L PEG with AA group. The incidence of adverse events did not differ significantly between the groups (12.9% vs 11.9%, p=0.871). Conclusions One liter-PEG with AA is not inferior to 2-L PEG with AA in terms of adequate SBVQ for SBCE. One liter-PEG with AA can be recommended as the standard method for bowel cleansing for SBCE.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Background/Aims: Post-infectious irritable bowel syndrome (PI-IBS) is characterized by chronic gastrointestinal symptoms that arise following an episode of infectious enteritis. The incidence rates vary, ranging from 5% to 32% and the risk factors are not well known. We aim to investigate the incidence and risk factors of PI-IBS in enteritis patients admitted to university hospitals in Korea. Methods: This multi-center prospective study was conducted in patients hospitalized for infectious enteritis. Each patient underwent 1 outpatient visit and 3 telephone surveys during the first year after discharge to determine if PI-IBS occurred within the follow-up period. Results: In the 3-month survey, 7 out of 354 patients (2%) were diagnosed with PI-IBS, and after 1 year, only 1 patient met the criteria for IBS.No statistically significant difference was found between the PI-IBS group and the non-PI-IBS group in terms of age, sex, underlying diseases, medication history, gastrointestinal symptoms, enteritis location, causative strain, hospitalization and treatment periods, and laboratory findings. Female sex (P = 0.003), enteropathogenic Escherichia coli (EPEC) infection (P = 0.044), and a longer total treatment period (P = 0.018) were independent risk factors for diarrhea lasting ≥ 3 months after enteritis. Conclusions The incidence of PI-IBS in Korea was relatively low, and most cases improved over time. No risk factors associated with the development of PI-IBS were found. However, persistent diarrhea after enteritis was associated with female sex, EPEC infection, and severe or long-lasting enteritis. IBS symptoms may persist after severe enteritis but usually improve with time.