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.

Over the past two decades, experimental and clinical evidence has established the interleukin-23 (IL-23)/interleukin-17 (IL-17) axis as a key mediator of psoriatic inflammation. IL-23, primarily derived from activated dendritic cells, supports the survival and pathogenic function of type 17 immune cells, which subsequently release IL-17A, IL-17F, and IL-22 to promote keratinocyte activation and recruit inflammatory leukocytes. These mechanistic insights have directly translated into the development of highly effective biologic therapies targeting IL-17 or IL-23, substantially improving the management of psoriasis. Beyond injectable biologics, growing efforts to overcome limitations related to long-term adherence, cost, and accessibility have accelerated the development of non-injectable therapeutic approaches. Oral and topical small-molecule agents, including selective tyrosine kinase 2 (TYK2) inhibitors and IL-23 receptor antagonists, are now broadening the therapeutic options. At the same time, progress in molecular engineering, artificial intelligence–guided protein design, and spatial multi-omic technologies are refining therapeutic discovery and enabling more precise targeting of pathogenic immune circuits. In this review, we outline the current understanding of the IL-23/IL-17 pathway in psoriasis pathogenesis and provide a critical overview of approved and emerging therapies directed at this pathway. We also address key biological and translational challenges, including tissue-specific cytokine functions, interspecies differences, and long-term safety considerations, and discuss how these factors may inform future strategies for precision immunotherapy in psoriasis.

Background: Although patients with malignant melanoma in situ (MIS) have a high survival rate, a risk of recurrence or upstaging remains. Thus, a comprehensive understanding of its prognosis is essential for optimal patient management. Objective: To investigate the clinical characteristics and survival outcomes of Korean patients with MIS. Methods: We retrospectively analyzed the medical records and photographs of patients with MIS treated at a single tertiary center between 2008 and 2021. Clinical features, including diagnosis, treatment, recurrence, and mortality, were examined. Results: A total of 156 patients with MIS were included, with a mean age of 59.3 years. The most common subtype was acral lentiginous melanoma (80.8%). Delayed diagnosis was associated with subungual MIS (SUMis; p ＜0.05). Among the subtypes other than SUMis, 77.3% met three or more of the ABCD criteria for melanoma.Hutchinson’s sign was observed in 67.3% of cases of SUMis. Ulceration was present in only two cases (1.3%).Recurrence occurred in nine patients (5.8%), with four (2.6%) experiencing relapse after 5 years. Upstaging was observed in two patients (1.3%) due to intralymphatic or regional nodal metastasis occurring at 19 and 10 months post-treatment. The 5-year and 10-year melanoma-specific/overall survival rates were 100.0/96.9% and 100.0/89.0%, respectively. Conclusion Although the survival rates of patients with MIS are high, long-term and close follow-up after treatment is essential because of the possibility of late recurrence and rare instances of intralymphatic or regional nodal metastasis. Additionally, the presence of clinical ulceration is highly suggestive of invasive melanoma.

Background: The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments. Materials and Methods: We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19. Results: During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis. Conclusion Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.

Purpose: Claudin 18.2 (CLDN18.2) has emerged as a promising therapeutic target for CLDN18.2-expressing gastric cancer (GC). We sought to examine the heterogeneity of CLDN18.2 expression between primary GC (PGC) and metastatic GC (MGC) using various scoring methods. Materials and Methods: We retrospectively analyzed data from 102 patients with pathologically confirmed paired primary and metastatic gastric or gastroesophageal junction adenocarcinomas. CLDN18.2 expression was evaluated through immunohistochemistry on formalin-fixed paraffin-embedded tissue samples. We assessed CLDN18.2 positivity using multiple scoring approaches, including the immunoreactivity score, H-score, and the percentage of tumor cells showing moderate-to-strong staining intensity. We analyzed the concordance rates between PGC and MGC and the association of CLDN18.2 positivity with clinicopathological features. Results: CLDN18.2 positivity varied from 25% to 65% depending on the scoring method, with PGC consistently showing higher expression levels than MGC. Intratumoral heterogeneity was noted in 25.5% of PGCs and 19.6% of MGCs. Intertumoral heterogeneity, manifesting as discordance in CLDN18.2 positivity between PGC and MGC, was observed in about 20% of cases, with moderate agreement across scoring methods (κ=0.47 to 0.60).In PGC, higher CLDN18.2 positivity correlated with synchronous metastasis, presence of peritoneal metastasis, poorly differentiated grade, and biopsy specimens. In MGC, positivity was associated with synchronous metastasis, presence of peritoneal metastasis, and metastatic peritoneal tissues. Conclusions CLDN18.2 expression demonstrates significant heterogeneity between PGC and MGC, with a 20% discordance rate. Comprehensive tissue sampling and reassessment of CLDN18.2 status are crucial, especially before initiating CLDN18.2-targeted therapies.

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.

Background: Despite the critical importance of sleep medicine within neurology, notable gaps in education and clinical practice persist among neurologists. This study aims to explore the extent of involvement and the challenges faced by Korean neurologists in sleep medicine, focusing on awareness of polysomnography training program, the operation of sleep study facilities, and educational exposure. Methods: An online survey collected responses from 233 neurologists, focusing on their demographics, knowledge of and involvement in sleep medicine, operation of sleep study facilities, and participation in residency training. Results: The findings indicated that 84.9% of neurologists were aware of polysomnography training program, primarily through professional societies. Nonetheless, 15.1% reported unfamiliarity with these initiatives, with 72.7% of this subgroup expressing interest in sleep medicine yet lacking access to information. In terms of clinical practice, 74 neurologists operated sleep study facilities, with 63% intending to expand. Key operational challenges included staff management, maintaining patient volumes, and inadequate institutional support. Among respondents from teaching hospitals, only 36 out of 114 reported active resident involvement in sleep study interpretations, predominantly hindered by excessive workloads and insufficient staffing. Conclusions A significant number of neurologists have an interest in sleep medicine; however, substantial challenges impede effective education and clinical practice. These results underscore the need for improved educational resources and institutional support to enhance the growth and effectiveness of sleep medicine practices among neurologists.

Objective: Cardiac arrest and cardiopulmonary resuscitation (CA/R) lead to whole-body ischemia and reperfusion (IR) injury, causing multiple organ dysfunction, including ischemic spinal cord injury. The thoracic spinal cord levels are crucial for maintaining the sympathetic functions vital for life. This study examined blood-spinal cord barrier (BSCB) leakage and astrocyte endfeet (AEF) disruption and their effects on survival, physiological variables, and neuronal damage/death in the intermediate zone (IMZ) at the seventh thoracic spinal cord level after asphyxial CA/R in rats. Methods: The rats underwent whole-body IR injury by asphyxial CA/R. Kaplan-Meier analysis was conducted to assess the cumulative survival post-CA/R. The histological changes post-CA/R were evaluated using immunohistochemistry, histofluorescence, and double histofluorescence. Results: No significant differences in body weight, mean arterial pressure, and heart rate were found between the sham and CA/R groups post-CA/R. The survival rates in the CA/R group at 12, 24, and 48 hours were 62.58%, 36.37%, and 7.8%, respectively. Neuronal loss and BSCB leakage began 12 hours post-CA/R, increasing with time. Reactive astrogliosis appeared at 12 hours and increased, while AEF disruption around blood vessels was evident at 48 hours. Conclusion The survival rate declined significantly by 48 hours post-CA/R. Neuronal loss and BSCB leakage in the thoracic spinal cord IMZ was evident at 12 hours and significant by 48 hours, aligning with AEF disruption. Neuronal loss in the thoracic spinal cord IMZ post-CA/R may be related to BSCB leakage and AEF disruption.