Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Purpose: To report a nationwide survey on neuroblastoma conducted by the Korean Association of Pediatric Surgeons (KAPS) in 2020. Methods: The clinical data of pediatric patients diagnosed with and treated for neuroblastoma from 2005 to 2019 in 19 hospitals of KAPS members were collected. Survival and prognostic factor analyses were performed using the log rank test and Cox proportional hazard analysis. A p-value <0.05 was considered significant. Results: A total of 669 patients with neuroblastoma were registered for the study. The results were presented and discussed at the 36th annual meeting of the KAPS, which was held in Seoul on August 21, 2020. Conclusion This study provides information on patient demographics, prognostic outcomes, and comprehensive treatment outcomes for neuroblastoma. The study is expected to be an important reference for improving pediatric surgeons’ understanding and treatment of neuroblastoma.

Purpose: Biliary atresia (BA) is a rare but progressive cholangiopathy and the leading cause of pediatric liver transplantation worldwide. The Korean Association of Pediatric Surgeons (KAPS) has conducted three national surveys (2001, 2011, and 2023) to assess long-term trends in the diagnosis, treatment, and outcomes of BA. This study provides a comparative analysis of the 2nd and 3rd national surveys, with reference to selected findings from the 1st survey. Methods: This study included 453 patients from the 3rd national survey (2011–2021) and 435 patients from the 2nd survey (2001–2010), all of whom underwent Kasai portoenterostomy. Data were collected via electronic case report forms from pediatric surgical centers nationwide. Comparisons were made regarding demographics, clinical features, diagnostic patterns, operative details, follow-up outcomes, and survival. Kaplan–Meier analysis was used to evaluate long-term survival. Results: The mean number of BA patients per year remained stable between surveys (43.5 in the 2nd, 41.18 in the 3rd), though centralization of care increased, with 61.5% of cases managed by two major institutions in the 3rd survey. The median age at surgery decreased, and the use of preoperative imaging (especially magnetic resonance cholangiopancreatography) increased. The 10-year native liver survival rate declined from 59.8% to 53.7%, while overall 10-year survival improved slightly (92.9% to 93.2%). Postoperative complications, such as cholangitis and liver failure, persisted but were better categorized. The 3rd survey also reported improved mortality (4.9%) and reduced follow-up loss (11.5%) compared to the 2nd survey. Conclusion While overall survival after Kasai operation has remained high and even improved, native liver survival has slightly declined. The findings reflect earlier diagnosis, more consistent diagnostic imaging, and increasing centralization of care. These trends underscore the importance of long-term nationwide data collection in guiding future strategies for BA management in Korea.

Purpose: Huge (≥10 cm) hepatocellular carcinoma (HCC) poses significant treatment and prognosis challenges. This study aimed to determine whether preoperative transarterial chemoembolization (TACE) for huge HCC is necessary. Methods: This single-center, retrospective cohort study evaluated 435 patients with huge HCC who underwent upfront hepatectomy or hepatectomy after preoperative TACE from January 2009 to December 2018. TACE’s impact on survival and prognostic factors, including microvascular invasion (MVI) and satellite nodules (SNs), was analyzed. Results: The preoperative TACE group (n = 33) had a lower incidence of MVI (P = 0.009) and higher postoperative morbidity (P = 0.001), particularly pleural effusion (P = 0.004) and Clavien-Dindo class III–IV complications (P = 0.033), compared with the upfront hepatectomy group (n = 402). Short-term mortality (P = 0.828) and recurrence within 6 months (P = 0.654) were comparable between groups. The 1-, 3-, and 5-year survival curves showed no significant between-group differences in recurrence-free survival (RFS) (P = 0.172) and overall survival (OS) (P = 0.450). Local regional therapy for intrahepatic recurrences and surgical resection for extrahepatic recurrences were associated with better OS. MVI, SN, and hepatic vein tumor thrombosis were identified as significant risk factors for poorer RFS and OS. In patients without SN, preoperative TACE improved RFS (P = 0.039) but not OS. Conclusion Preoperative TACE for huge HCC was associated with reduced MVI but did not improve RFS and OS. Survival outcomes were more significantly influenced by SN, suggesting that upfront hepatectomy without TACE should be prioritized.

Multiple myeloma (MM), a hematological malignancy, is characterized by malignant plasma cell proliferation in the bone marrow. Recent treatment advances have significantly improved patient outcomes associated with MM.In this study, we aimed to develop comprehensive, evidence-based guidelines for the diagnosis, prognosis, and treat‑ ment of MM. We identified 12 key clinical questions essential for MM management, guiding the extensive literature review and meta-analysis of the study. Our guidelines provide evidence-based recommendations by integrating patient preferences with survey data. These recommendations include current and emerging diagnostic tools, thera‑ peutic agents, and treatment strategies. By prioritizing a patient-centered approach and rigorous data analysis, these guidelines were developed to enhance MM management, both in Korea and globally.

Purpose: This study aimed to describe adult living donor liver transplantation (LDLT) for acute liver failure and evaluate its clinical significance by comparing its surgical and survival outcomes with those of deceased donor liver transplantation (DDLT). Methods: We retrospectively reviewed the medical records of 267 consecutive patients (161 LDLT recipients and 106 DDLT recipients) aged 18 years or older who underwent liver transplantation between January 2006 and December 2020. Results: The mean periods from hepatic encephalopathy to liver transplantation were 5.85 days and 8.35 days for LDLT and DDLT, respectively (P = 0.091). Among these patients, 121 (45.3%) had grade III or IV hepatic encephalopathy (living, 34.8% vs. deceased, 61.3%; P < 0.001), and 38 (14.2%) had brain edema (living, 16.1% vs. deceased, 11.3%; P = 0.269) before liver transplantation. There were no significant differences in in-hospital mortality (living, 11.8% vs. deceased, 15.1%; P = 0.435), 10-year overall survival (living, 90.8% vs. deceased, 84.0%; P = 0.096), and graft survival (living, 83.5% vs. deceased, 71.3%;P = 0.051). However, postoperatively, the mean intensive care unit stay was shorter in the LDLT group (5.0 days vs. 9.5 days, P < 0.001). In-hospital mortality was associated with vasopressor use (odds ratio [OR], 3.40; 95% confidence interval [CI], 1.45–7.96; P = 0.005) and brain edema (OR, 2.75; 95% CI, 1.16–6.52; P = 0.022) of recipient at the time of transplantation. However, LDLT (OR, 1.26; 95% CI, 0.59–2.66; P = 0.553) was not independently associated with in-hospital mortality. Conclusion LDLT is feasible for acute liver failure when organs from deceased donors are not available.

Purpose: This subgroup analysis of the Korean subset of patients in the phase 3 LASER301 trial evaluated the efficacy and safety of lazertinib versus gefitinib as first-line therapy for epidermal growth factor receptor mutated (EGFRm) non–small cell lung cancer (NSCLC). Materials and Methods: Patients with locally advanced or metastatic EGFRm NSCLC were randomized 1:1 to lazertinib (240 mg/day) or gefitinib (250 mg/day). The primary endpoint was investigator-assessed progression-free survival (PFS). Results: In total, 172 Korean patients were enrolled (lazertinib, n=87; gefitinib, n=85). Baseline characteristics were balanced between the treatment groups. One-third of patients had brain metastases (BM) at baseline. Median PFS was 20.8 months (95% confidence interval [CI], 16.7 to 26.1) for lazertinib and 9.6 months (95% CI, 8.2 to 12.3) for gefitinib (hazard ratio [HR], 0.41; 95% CI, 0.28 to 0.60). This was supported by PFS analysis based on blinded independent central review. Significant PFS benefit with lazertinib was consistently observed across predefined subgroups, including patients with BM (HR, 0.28; 95% CI, 0.15 to 0.53) and those with L858R mutations (HR, 0.36; 95% CI, 0.20 to 0.63). Lazertinib safety data were consistent with its previously reported safety profile. Common adverse events (AEs) in both groups included rash, pruritus, and diarrhoea. Numerically fewer severe AEs and severe treatment–related AEs occurred with lazertinib than gefitinib. Conclusion Consistent with results for the overall LASER301 population, this analysis showed significant PFS benefit with lazertinib versus gefitinib with comparable safety in Korean patients with untreated EGFRm NSCLC, supporting lazertinib as a new potential treatment option for this patient population.

Purpose: The role of allogeneic stem cell transplantation (alloSCT) in multiple myeloma (MM) treatment remains controversial. We conducted a retrospective, multicenter, nationwide study in Korea to evaluate the outcomes of alloSCT in Asian patients with MM. Materials and Methods: Overall, 109 patients with MM who underwent alloSCT between 2003 and 2020 were included in this study. Data were collected from the Korean Multiple Myeloma Working Party Registry. Results: The overall response rate and stringent complete response plus complete response (CR) rates were 67.0 and 46.8%, respectively, after alloSCT. At a median follow-up of 32.5 months, the 3-year probability of progression-free survival (PFS) and overall survival (OS) rates were 69.3% and 71.8%, respectively. The 3-year probabilities of OS rates in the upfront alloSCT, tandem auto-alloSCT, and later alloSCT groups were 75.0%, 88.9%, and 61.1%, respectively. Patients who achieved CR before or after alloSCT had significantly longer OS (89.8 vs. 18 months and 89.8 vs. 15.2 months, respectively). Even though patients who did not achieve CR prior to alloSCT, those who achieve CR after alloSCT had improved PFS and OS compared to those who had no achievement of CR both prior and after alloSCT. Patients who underwent alloSCT with 1-2 prior treatment lines had improved PFS (22.4 vs. 4.5 months) and OS (45.6 vs. 15.3 months) compared to those with three or more prior treatment lines. Conclusion AlloSCT may be a promising therapeutic option especially for younger, chemosensitive patients with earlier implementation from relapse.

With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

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.