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.

Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.

Background/Aims: We used next-generation sequencing (NGS) to analyze resistance-associated substitutions (RASs) and retreatment outcomes in patients with chronic hepatitis C virus (HCV) infection who failed direct-acting antiviral agent (DAA) treatment in South Korea. Methods: Using prospectively collected data from the Korean HCV cohort study, we recruited 36 patients who failed DAA treatment in 10 centers between 2007 and 2020; 29 blood samples were available from 24 patients. RASs were analyzed using NGS. Results: RASs were analyzed for 13 patients with genotype 1b, 10 with genotype 2, and one with genotype 3a. The unsuccessful DAA regimens were daclatasvir+asunaprevir (n=11), sofosbuvir+ribavirin (n=9), ledipasvir/sofosbuvir (n=3), and glecaprevir/pibrentasvir (n=1). In the patients with genotype 1b, NS3, NS5A, and NS5B RASs were detected in eight, seven, and seven of 10 patients at baseline and in four, six, and two of six patients after DAA failure, respectively. Among the 10 patients with genotype 2, the only baseline RAS was NS3 Y56F, which was detected in one patient. NS5A F28C was detected after DAA failure in a patient with genotype 2 infection who was erroneously treated with daclatasvir+asunaprevir. After retreatment, 16 patients had a 100% sustained virological response rate. Conclusions NS3 and NS5A RASs were commonly present at baseline, and there was an increasing trend of NS5A RASs after failed DAA treatment in genotype 1b. However, RASs were rarely present in patients with genotype 2 who were treated with sofosbuvir+ribavirin. Despite baseline or treatment-emergent RASs, retreatment with pan-genotypic DAA was highly successful in Korea, so we encourage active retreatment after unsuccessful DAA treatment.

Purpose: Single-incision laparoscopic distal gastrectomy (SIDG) requires experienced camera operators for a stable image. Since it is difficult for skilled camera operators to participate in all SIDG, we began performing solo surgery using mechanical camera holders. We aimed to compare the short-term outcomes and cost between solo SIDG and conventional multiport laparoscopic distal gastrectomy (MLDG) for early gastric cancer (EGC). Methods: From January 2014 to December 2016, a total of 938 consecutive patients underwent laparoscopic gastrectomy for EGC. Solo SIDG (n = 99) and MLDG patients (n = 198) were selected and 1:2 propensity score matching was done to compare the quality of operation and cost-effectiveness. All solo SIDG was performed by a surgeon using a camera holder, without any assistant. Results: Mean operation time (120 ± 35.3 vs. 178 ± 53.4 minutes, P = 0.001) and estimated blood loss (24.6 ± 47.4 vs. 46.7 ± 66.5 mL, P = 0.001) were significantly lower in the solo SIDG group. Hospital stay, use of analgesics, and postoperative inflammatory markers (WBC, CRP) were similar between the 2 groups. The early (<30 days) complication rate in solo SIDG and MLDG groups was 21.2% and 23.7%, respectively (P = 0.240); the late (≥30 days) complication rate was 7.1% and 11.1%, respectively (P = 0.672). The manpower cost of solo SIDG was significantly lower than that of MLDG (P = 0.001). Conclusion This study demonstrated that solo SIDG performed by experienced laparoscopic surgeons is safe and feasible for EGC. Solo SIDG is expected to be a promising potential treatment for EGC.

Objective: To evaluate the effects of maternal body mass index (BMI) and plurality on maternal and umbilical cord serum magnesium levels after antenatal magnesium sulfate treatment. Methods: This was a retrospective cohort analysis of 135 women treated with antenatal magnesium sulfate at less than 32 weeks of gestation between January 2012 and June 2018. Subjects were stratified into groups according to maternal BMI (group I [18.5–22.9 kg/m²], group II [23.0–24.9 kg/m²], and group III [≥25.0 kg/m²]) and plurality (singleton and twin). Univariable and multivariable analyses were performed to compare the umbilical cord serum magnesium levels between the groups. Results: Maternal serum magnesium levels were not significantly different between the maternal BMI groups and singleton and twin pregnancies. Umbilical cord serum magnesium levels were significantly different among the maternal BMI groups (3.3±1.2 mg/dL in group I, 3.3±1.2 mg/dL in group II, and 4.0±1.4 mg/dL in group III, P=0.003). The trend of increase in magnesium levels was statistically significant (P=0.001, Jonckheere-Terpstra test). Umbilical cord serum magnesium levels were not significantly different according to plurality. However, in the multivariable analysis, maternal BMI and plurality were not significantly associated with umbilical cord serum magnesium levels after adjusting for indication and total dose of magnesium sulfate treatment, gestational age at delivery, mode of delivery, neonatal sex, and birth weight. Conclusion Maternal BMI and plurality were not significantly associated with maternal or umbilical cord serum magnesium levels after exposure to antenatal magnesium sulfate treatment.

Purpose: The purpose of this study was to investigate the clinicopathologic characteristics of young gastric cancer patients and analyze the risk factors for stage underestimation and survival. Methods: Relevant data of 5029 patients who underwent surgery for gastric cancer at Seoul National University Bundang Hospital between 2003 to 2014 were collected. Patients were divided based on age (younger group and older group). Clinical stages were compared to pathologic stages for accuracy, and risk factors for underestimation were analyzed using univariate and multivariate analysis regression. Overall survival and cancer-specific survival were analyzed using the Kaplan-Meier method. Results: A total of 4396 patients were eligible for inclusion. The younger group was an independent risk factor for nodal metastasis (RR=1.44, 95% CI 1.06~1.95) and an independent risk factor for clinical N-stage underestimation (RR=1.50, 95% CI=1.14~1.98). However, there was no significant difference in 5-year cancer-specific survival for both age groups (92.2% vs 90.2%, p=0.306). Conclusion In conclusion, intra-operative investigation of T-stage with standard operation should be done in young gastric cancer patients as they have a higher incidence of lymph node metastasis, with greater frequency of stage underestimation.

Background: and Purpose: The Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) is widely used for estimating the symptoms of Parkinson’s disease. Translation and validation of the MDS-UPDRS is necessary for non-English speaking countries and regions. The aim of this study was to validate the Korean version of the MDS-UPDRS. Methods: Altogether, 362 patients in 19 centers were recruited for this study. We translated the MDS-UPDRS to Korean using the translation-back translation method and cognitive pretesting. We performed both confirmatory and exploratory factor analyses to validate the scale.We calculated the comparative fit index (CFI) for confirmatory factor analysis, and used unweighted least squares for exploratory factor analysis. Results: The CFI was higher than 0.90 for all parts of the scale. Exploratory factor analysis also showed that the Korean MDS-UPDRS has the same number of factors in each part as the English version. Conclusions The Korean MDS-UPDRS has the same overall structure as the English MDSUPDRS. Our translated scale can be designated as the official Korean MDS-UPDRS.