Background: The Korean Endocrine Hormone Reference Standard Data Center (KEHRS DC) has created reference standards (RSs) for endocrine hormones since 2020. This study is the first of its kind, wherein the KEHRS DC established RSs for serum Cpeptide levels in a healthy Korean population. Methods: Healthy Korean adults were recruited from May 2021 to September 2023. After excluding participants according to our criteria, serum samples were collected; each participant could then choose between fasting glucose only or fasting glucose plus an oral glucose tolerance test (OGTT). If their sample showed high glucose (≥100 mg/dL) or hemoglobin A1c (HbA1c) (≥5.70%), their C-peptide levels were excluded from analyzing the RSs. Results: A total of 1,532 participants were recruited; however, only the data of 1,050 participants were analyzed after excluding those whose samples showed hyperglycemia or high HbA1c. Post-30-minute OGTT data from 342 subjects and post-120-minute OGTT data from 351 subjects were used. The means±2 standard deviations and expanded uncertainties of fasting, post-30-minute and 120-minute OGTT C-peptide levels were 1.26±0.82 and 0.34–3.18, 4.74±3.57 and 1.14–8.33, and 4.85±3.58 and 1.25–8.34 ng/mL, respectively. Serum C-peptide levels correlated with obesity, serum glucose levels, and HbA1c levels. Conclusion The RSs for serum C-peptide levels established in this study are expected to be useful in both clinical and related fields.

Purpose: The purpose of this study was to evaluate the clinical characteristics and treatment outcomes of alveolar soft part sarcoma (ASPS) of the extremities and trunk and investigate the prognostic factors. Materials and Methods: Forty patients presenting with ASPS in the extremities or trunk between 2001 and 2021 were reviewed retrospectively. We evaluated the clinical manifestations at presentation, local recurrence, and metastasis after treatment. The survival rates and prognostic factors affecting survival were analyzed. Only patients who were followed up for more than one year were included in the study. The mean follow-up time was 58 months (range, 12–120). Results: The average age of the patients was 26 years (range, 12–54) and the primary tumor developed mainly in the thigh (23 patients, 57.5%). The average size of the tumor was 8.7 cm and metastasis at presentation was seen in 28 (70%) patients. The overall survival rates at five-years and 10-years were 53.7% and 34.5%, respectively. Metastasis at presentation was related to poor survival (p=0.001). Conclusion ASPS in the extremities or trunk present with a high rate of metastasis and patients with metastasis showed poorer survival.In the future, further efforts to develop novel therapies like target therapy or immunotherapy for the treatment of metastatic patients are warranted.

Purpose: Giant cell tumor (GCT) of the proximal femur is relatively rare, with only a few case series reported thus far. This study aimed to evaluate the clinical outcomes of GCT of the proximal femur treated with intralesional curettage and expand the understanding of their characteristics and treatment considerations. Materials and Methods: Fifteen cases treated with curettage for GCT of the proximal femur between 2007 and 2020 were reviewed. The median follow-up was 46 months (25–150 months). There were 10 males and 5 females with a median age of 26 years (17–71 years). After curettage, the bone defect was filled with either an allograft (7 cases) or bone cement (8 cases). Results: The postoperative complications were local recurrences in three cases (20.0%), including malignant transformation in one case and a femur neck fracture in one case (6.7%) following curettage and strut allograft. Among the 15 cases, 13 (86.7%) retained their native joint at the last follow-up. No patients developed degenerative changes or osteonecrosis. Conclusion The results of proximal femoral GCT with curettage were acceptable despite local recurrences in three cases (20.0%), and femur neck fracture in one case. An appropriate surgical approach and reconstruction according to the extent of the lesion are necessary for successful treatment.

Background: Lung cancer is associated with significant psychological distress, including fear of progression (FoP). Because insomnia and depression are highly prevalent and associated with FoP, we examined the association between FoP, insomnia, and depression in cancer patients. Furthermore, we tested the mediation effect of cancer-related dysfunctional beliefs about sleep (C-DBS) on this association. Methods: We analyzed data collected from patients with surgically resected non-small cell lung cancer from a single-center randomized controlled study investigating digital healthcare applications. Baseline demographic and clinical variables were collected. In addition, selfreported questionnaires including the Fear of Progression Questionnaire-Short Form, Patients Health Questionnaire-9 items (PHQ-9), Insomnia Severity Index, and C-DBS were administered. Results: Among the 320 enrolled patients with lung cancer, a regression model showed that FoP was predicted by age (β = −0.13, P = 0.007), PHQ-9 (β = 0.35, P < 0.001), and C-DBS (β = 0.28, P < 0.001). Insomnia did not directly influence FoP, but C-DBS mediated the association. Depression directly influenced FoP, but C-DBS did not mediate this association. Conclusion Among patients with surgically resected lung cancer, C-DBS mediated the effects of severity of insomnia on FoP. Depression directly influenced FoP, but C-DBS did not influence this association. To reduce FoP among patients with lung cancer, C-DBS should be addressed in the cognitive behavioral therapy module.

Purpose: This multi-center, retrospective study was conducted to evaluate the long-term survival in patients who underwent surgical resection for small cell lung cancer (SCLC) and to identify the benefit of adjuvant therapy following surgery. Materials and Methods: The data of 213 patients who underwent surgical resection for SCLC at four institutions were retrospectively reviewed. Patients who received neoadjuvant therapy or an incomplete resection were excluded. Results: The mean patient age was 65.29±8.93 years, and 184 patients (86.4%) were male. Lobectomies and pneumonectomies were performed in 173 patients (81.2%), and 198 (93%) underwent systematic mediastinal lymph node dissections. Overall, 170 patients (79.8%) underwent adjuvant chemotherapy, 42 (19.7%) underwent radiotherapy to the mediastinum, and 23 (10.8%) underwent prophylactic cranial irradiation. The median follow-up period was 31.08 months (interquartile range, 13.79 to 64.52 months). The 5-year overall survival (OS) and disease-free survival were 53.4% and 46.9%, respectively. The 5-year OS significantly improved after adjuvant chemotherapy in all patients (57.4% vs. 40.3%, p=0.007), and the survival benefit of adjuvant chemotherapy was significant in patients with negative node pathology (70.8% vs. 39.7%, p=0.004). Adjuvant radiotherapy did not affect the 5-year OS (54.6% vs. 48.5%, p=0.458). Age (hazard ratio [HR], 1.032; p=0.017), node metastasis (HR, 2.190; p < 0.001), and adjuvant chemotherapy (HR, 0.558; p=0.019) were associated with OS. Conclusion Adjuvant chemotherapy after surgical resection in patients with SCLC improved the OS, though adjuvant radiotherapy to the mediastinum did not improve the survival or decrease the locoregional recurrence rate.

Background/Aims: Fecal microbiota transplantation (FMT) represents a treatment option for recurrent Clostridioides difficile infection (CDI). Recently, FMT has been investigated in various clinical settings other than CDI. This study examined Korean physicians’ recognition of FMT and their attitudes toward this procedure Methods: An online questionnaire included questions on indications for FMT, the FMT process, physicians’ attitudes toward FMT for the treatment of CDI and non-CDI diseases, and possible concerns. Results: Finally, 107 physicians responded to this survey: 66 (61.7%) had experience of performing FMT, and 86 (80.4%) replied that they were willing to perform FMT for CDI. Two-thirds of physicians (63.6%, n = 68) would perform FMT for recurrent CDI on patients who had at least three recurrences. The most common obstacle to performing FMT for the treatment of CDI was the lack of regulations or guidelines (55.1%, n = 59). Seventy-seven (72.0%) physicians would consider FMT for non- CDI diseases when conventional treatment had failed. The most common obstacle for FMT for the treatment of non-CDI diseases was low treatment efficacy (57.0%, n = 61). Conclusions Two-thirds of Korean physicians had experience of performing FMT, and many performed FMT for recurrent CDI. The results of this study will prove useful to researchers and practitioners in FMT in Korea.

Objective: Easy-to-understand information on emergency patient transportation and emergency medical resources is required to operate emergency medical resources appropriately. This study evaluated emergency patient transport routes using a geographic information system (GIS) and converted them into visual information to understand the current status of emergency medical resource use in the region. Methods: The basic data used in this study were collected from the 119 safety centers in Gangwon-do, South Korea, under the fire-fighting headquarters in Gangwon-do from January 2017 to December 2020. The data were analyzed using the geographic information system and converted to visual information. Results: The number of patients with cardiovascular disease, cerebrovascular disease, and traffic accidents was 12,944. Of these, 9,393 patients (72.6%) were transported from Chuncheon city, and 3,551 patients (27.4%) were transported out of Chuncheon city. The number of patients with cardiovascular diseases during the study period was 1,219 (9.4%); 782 patients (64.2%) were transported to the K-EMC (emergency medical center), and 437 patients (35.8%) were transported to the H-EMC. For cerebrovascular disease, 913 patients (7.1%) were transported to the EMC of Chuncheon city, with 585 (64.1%) K-EMC and 328 (35.9%) H-EMC patients. The number of traffic accident patients was 1,266 (9.8%). Five hundred and forty (42.7%) and 726 (57.3%) patients were transported to the K-EMC and H-EMC, respectively. Conclusion The adequacy of facilities, equipment, and human resources required to treat cardiac and cerebrovascular diseases in K-EMC and severe trauma in H-EMC needs to be reviewed.

Purpose: The aim of this study is to evaluate the safety and efficacy of ex vivo activated and expanded natural killer (NK) cell therapy (SNK01) plus pembrolizumab in a randomized phase I/IIa clinical trial. Materials and Methods: Overall, 18 patients with advanced non–small cell lung cancer (NSCLC) and a programmed death ligand 1 tumor proportion score of 1% or greater who had a history of failed frontline platinum-based therapy were randomized (2:1) to receive pembrolizumab every 3 weeks +/– 6 weekly infusions of SNK01 at either 2×109 or 4×109 cells per infusion (pembrolizumab monotherapy vs. SNK01 combination). The primary endpoint was safety, whereas the secondary endpoints were the objective response rate (ORR), progression-free survival (PFS), overall survival, and quality of life. Results: Since no dose-limiting toxicity was observed, the maximum tolerated dose was determined as SNK01 4×109 cells/dose. The safety data did not show any new safety signals when SNK01 was combined with pembrolizumab. The ORR and the 1-year survival rate in the NK combination group were higher than those in patients who underwent pembrolizumab monotherapy (ORR, 41.7% vs. 0%; 1-year survival rate, 66.7% vs. 50.0%). Furthermore, the median PFS was higher in the SNK01 combination group (6.2 months vs. 1.6 months, p=0.001). Conclusion Based on the findings of this study, the NK cell combination therapy may consider as a safe treatment method for stage IV NSCLC patients who had a history of failed platinum-based therapy without an increase in adverse events.

Fecal microbiota transplantation (FMT) is a highly efficacious and safe modality for the treatment of recurrent or refractory Clostridioides difficile infection (CDI), with overall success rates of 90%. Thus, FMT has been widely used for 10 years. The incidence and clinical characteristics of CDI, the main indication for FMT, differ between countries. To date, several guidelines have been published. However, most of them were published in Western countries and therefore cannot represent the Korean national healthcare systems. One of the barriers to performing FMT is a lack of national guidelines. Accordingly, multidisciplinary experts in this field have developed practical guidelines for FMT. The purpose of these guidelines is to aid physicians performing FMT, which can be adapted to treat CDI and other conditions.

Restless legs syndrome (RLS) is a common neurological illness marked by a strong desire to move one’s legs, usually in association with uncomfortable sensations. Recent studies have investigated brain networks and connectivity in RLS. The advent of network analysis has greatly improved our understanding of the brain and various neurological disorders. A few studies have investigated alterations in functional connectivity in patients with RLS. This article reviews functional connectivity studies of patients with RLS, which have identified significant alterations relative to healthy controls in several brain networks including thalamic, salience, default-mode, and small-world networks. In addition, network changes related to RLS treatment have been found, including to repetitive transcranial magnetic stimulation, transcutaneous spinal cord direct-current stimulation, and dopaminergic drugs. These findings suggest that the underlying pathogenesis of RLS includes alterations in the functional connectivity in the brain and that RLS is a network disorder.