Purpose: Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood. Materials and Methods: We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared. Results: A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes. Conclusions GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.

Purpose: Non-operative management (NOM) has emerged as a promising organ-preserving strategy for patients with rectal cancer who achieve a clinical complete response (cCR) after neoadjuvant chemoradiotherapy (CRT). However, no standardized treatment protocol has been established for watch-and-wait strategies. Materials and Methods: This prospective study evaluated oncological outcomes of NOM combined with 4 months of adjuvant capecitabine. Patients with resectable rectal cancer (≤ 8 cm from the anal verge, cT2-4 or N+) underwent CRT (50-54 Gy in 25-27 fractions with capecitabine). Eight weeks post-CRT, a multidisciplinary team assessed cCR. Patients achieving cCR received six cycles of capecitabine (2 weeks on/1 week off) and were actively monitored. Results: Among 89 patients receiving CRT (2018-2023), 17 (19.1%) achieved cCR and were included. The median age was 65 years, and 64.7% were male. Eleven (64.7%) completed all six cycles of adjuvant therapy. After a median follow-up of 31.4 months, 11 patients (64.7%) remained disease-free. Local regrowth occurred in six patients (35.3%) with 2- and 4-year rates of 34.5% and 47.6%, respectively. Five underwent radical surgery, and one received transanal excision with systemic chemotherapy. At the time of assessment, 15 patients (88.2%) showed no evidence of disease, while two (11.8%) received palliative chemotherapy. All patients were alive. Conclusion NOM with adjuvant capecitabine showed promising oncological outcomes, offering an alternative to passive watch-and-wait approaches. Further refinement through multidisciplinary strategies is warranted.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

Background: Post-transplantation cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are common pro‑ phylactic strategies for graft-versus-host disease (GVHD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Interleukin (IL)-6 is a surrogate marker for cytokine release syndrome (CRS) and acute GVHD.Method The clinical outcomes and complications of haplo-HSCT with PTCy plus ATG versus PTCy monotherapy were compared according to serum IL-6 levels at Chungnam National University Hospital (Daejeon, South Korea) from Jan‑ uary 2019 to February 2023. Results: Forty patients who underwent haplo-HSCT were analyzed. A significant difference in IL-6 levels was observed between the PTCy plus ATG and PTCy alone groups (7.47 ± 10.55 vs. 117.65 ± 127.67; p = 0.003). More patients in the PTCy plus ATG group had a CRS grade of 0 than in the PTCy alone group (p < 0.001). Serum IL-6 levels were associated with grades II–IV acute GVHD (r = 0.547, p < 0.001). The cumulative incidence (CI) of grades II–IV acute GVHD was significantly higher in the PTCy alone group (67.9% vs. 4.8%; p < 0.001). No significant difference in the CI for chronic GVHD was detected between the PTCy plus ATG and PTCy alone groups (72.1% vs. 82.0%; p = 0.730). The CI of 1-year non-relapse mortality was significantly higher in the PTCy alone group than in the PTCy plus ATG group (42.2% vs. 15.9%; p = 0.022). The 1-year overall survival (OS) was significantly better in the PTCy plus ATG group (75.9% vs. 35.3%; p = 0.011). The 1-year GVHD-free, relapse-free survival rate was 29.4% in the PTCy alone group and 54.0% in the PTCy plus ATG group (p = 0.038). Conclusion Serum IL-6 levels were higher in the PTCy alone group than in the PTCy plus ATG group. The addition of ATG before stem cell infusion affected IL-6 levels and reduced the incidences of CRS and grade II–IV acute GVHD in haplo-HSCT patients. This study suggests that PTCy plus ATG as GVHD prophylaxis in haplo-HSCT is beneficial in terms of clinical outcomes and complications of HSCT.

Purpose: This network meta-analysis aimed to evaluate the relative efficacy of systemic treatments in patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL), focusing on key genetic mutations, specifically the 17p deletion and TP53 mutations. Methods: We conducted a systematic literature review to identify all publicly available randomized controlled trials (RCTs) using PubMed, EMBASE, the Cochrane database, and meeting abstracts published through December 2023.A Bayesian network meta-analysis was performed to estimate the hazard ratios (HRs) for progression-free survival (PFS) with 95% confidence intervals (CIs) and to determine the ranking of the included regimens. Results: Twelve trials involving 4,437 patients and 13 treatment options were included in the meta-analysis. Venetoclax plus rituximab and zanubrutinib emerged as the most effective treatments for the overall R/R CLL population, showing the lowest PFS HR (HR 0.62, 95% CI 0.32–1.20 and HR 0.65, 95% CI 0.49–0.86, respectively) versus ibrutinib, and were ranked as the best agent (surface under the cumulative ranking curve [SUCRA] value of both 90%, respectively) among the included drugs. In the 17p deletion/TP53 mutation subgroup, zanubrutinib demonstrated the most favorable efficacy (HR 0.52, 95% CI 0.31–0.88 versus ibrutinib) with the highest SUCRA value (97%). In patients without these mutations, venetoclax plus rituximab was the most effective (HR 0.49, 95% CI 0.26–0.94 versus ibrutinib) with a SUCRA value of 94%. Conclusion Our findings highlight the superior efficacy of venetoclax plus rituximab and zanubrutinib for treating R/R CLL and confirm that the role of each regimen may vary depending on the clinically significant mutations.

South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.

Background: The increasing incidence and mortality rates of tuberculosis among older individuals who suffer from multiple morbidities and are vulnerable to malnutrition are major obstacles to efforts to eradicate tuberculosis in the Republic of Korea. Herein, we identified the factors associated with mortality during anti-tuberculosis treatment in patients with pulmonary tuberculosis. Methods: We conducted a case-control study and extracted data from the database of a multi-center prospective observational cohort study in Korea. Among the participants with rifampicin-susceptible pulmonary tuberculosis, the survival group was defined as those who successfully completed treatment within one year, whereas the mortality group was defined as those who died during treatment. Univariable and multivariable logistic regression analyses were performed to identify factors associated with TB mortality. Results: Among 1,119 participants with pulmonary TB registered between 2019 and 2021, 799 and 59 were grouped in the survival and mortality groups, respectively. Age, positive smear results, alarming symptoms, nutrition risk score, Charlson comorbidity index score, and initial standard treatment regimen were significant based on univariable analysis and were selected for the multivariable logistic regression model. Nutrition risk score (adjusted odds ratio, 2.44; 95% confidence interval, 1.72–3.48) and Charlson comorbidity index score (adjusted odds ratio, 1.62; 95% confidence interval, 1.35–1.94) remained statistically significant in the multivariate analysis. Conclusion Nutritional status and comorbidities at baseline were identified as important factors associated with mortality in patients with pulmonary tuberculosis.

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is a neurodegenerative disorder caused by a biallelic expansion of pentanucleotide repeats in the RFC1 gene. Previous studies have reported up to 22% of patients with late-onset ataxia harbor this pathogenic repeat expansion. Despite its relatively high prevalence, CANVAS is often underdiagnosed because the disease is not well recognized and genetic testing is not performed in clinical practice. Here, we present a patient with characteristic clinical features, confirmed by genetic testing.