Purpose: This study aimed to develop a comprehensive practical guide for enteral nutrition (EN) designed to enhance patient safety and reduce complications in Korea. Under the leadership of the Korean Society for Parenteral and Enteral Nutrition (KSPEN), the initiative sought to standardize EN procedures, improve decision-making, and promote effective multidisciplinary communication. Methods: The KSPEN EN committee identified key questions related to EN practices and organized them into seven sections such as prescribing, delivery route selection, formula preparation, administration, and quality management. Twenty-one experts, selected based on their expertise, conducted a thorough literature review to formulate evidence-based recommendations. Drafts underwent peer review both within and across disciplines, with final revisions completed by the KSPEN Guideline Committee. The guide, which will be published in three installments, addresses critical elements of EN therapy and safety protocols. Results: The practical guide recommends that EN orders include detailed elements and advocates the use of electronic medical records for communication. Standardized prescription forms and supplementary safety measures are outlined. Review frequency is adjusted according to patient condition—daily for critically ill or unstable patients and as dictated by institutional protocols for stable patients. Evidence indicates that adherence to these protocols reduces mortality, complications, and prescription errors. Conclusion The KSPEN practical guide offers a robust framework for the safe delivery of EN tailored to Korea’s healthcare context. It emphasizes standardized protocols and interdisciplinary collaboration to improve nutritional outcomes, patient safety, and operational efficiency. Rigorous implementation and monitoring of adherence are critical for its success.

Purpose: Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma.Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL. Methods: This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT. Results: The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others. Conclusions R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Purpose: Extranodal natural killer/T-cell lymphoma (ENKTL) predominantly manifests in East Asia and Latin America. Despite shared intrinsic factors, such as ethnic and genetic backgrounds, the progression of ENKTL can be influenced by extrinsic factors related to changing lifestyle patterns. Materials and Methods: This study collected stool samples from newly diagnosed (ND)–ENKTL patients (n=40) and conducted whole genome shotgun sequencing. Results: ND-ENKTL revealed reduced alpha diversity in ND-ENKTL compared to healthy controls (HCs) (p=0.008), with Enterobacteriaceae abundance significantly contributing to the beta diversity difference between ENKTL and HCs (p < 0.001). Functional analysis indicated upregulated aerobic metabolism and degradation of aromatic compounds in ND-ENKTL. Enterobacteriaceae were associated not only with clinical data explaining disease status (serum C-reactive protein, stage, prognosis index of natural killer cell lymphoma [PINK], and PINK-E) but also with clinical outcomes (early relapse and short progression-free survival). The relative abundance of Enterobacteriaceae at the family level was similar between ENKTL and diffuse large B-cell lymphoma (DLBCL) (p=0.140). However, the ENKTL exhibited a higher abundance of Escherichia, in contrast to the prevalence of Enterobacter and Citrobacter in DLBCL. Linear regression analysis demonstrated a significant association between Escherichia abundance and programmed cell death-ligand-1 (PD-L1) levels in tissue samples (p=0.025), whereas no correlation with PD-L1 was observed for Enterobacteriaceae at the family level (p=0.571). Conclusion ND-ENKTL exhibited an abundance of Enterobacteriaceae and a dominant presence of Escherichia. These microbial characteristics correlated with disease status, treatment outcomes, and PD-L1 expression, suggesting the potential of the ENKTL microbiome as a biomarker and cause of lymphomagenesis, which warrants further exploration.

Purpose: Adjuvant treatment for craniopharyngioma after surgery is controversial. Adjuvant external beam radiation therapy (EBRT) can increase the risk of long-term sequelae. Stereotactic radiosurgery (SRS) is used to reduce treatment-related toxicity.In this study, we compared the treatment outcomes and toxicities of adjuvant therapies for craniopharyngioma. Materials and Methods: We analyzed patients who underwent craniopharyngioma tumor removal between 2000 and 2017. Of the 153 patients, 27 and 20 received adjuvant fractionated EBRT and SRS, respectively. We compared the local control (LC), progression-free survival (PFS), and overall survival between groups that received adjuvant fractionated EBRT, SRS, and surveillance. Results: The median follow-up period was 77.7 months. For SRS and surveillance, the 10-year LC was 57.2% and 57.4%, respectively. No local progression was observed after adjuvant fractionated EBRT. One patient in the adjuvant fractionated EBRT group died owing to glioma 94 months after receiving radiotherapy (10-year PFS: 80%). The 10-year PFS was 43.6% and 50.7% in the SRS and surveillance groups, respectively. The treatment outcomes significantly differed according to adjuvant treatment in nongross total resection (GTR) patients. Additional treatment-related toxicity was comparable in the adjuvant fractionated EBRT and other groups. Conclusion Adjuvant fractionated EBRT could be effective in controlling local failure, especially in patients with non-GTR, while maintaining acceptable treatment-related toxicity.

BACKGROUND/OBJECTIVES: This study aimed to use plasma metabolites to identify clusters of breast cancer survivors and to compare their dietary characteristics and health-related factors across the clusters using unsupervised machine learning. SUBJECTS/METHODS: A total of 419 breast cancer survivors were included in this crosssectional study. We considered 30 plasma metabolites, quantified by high-throughput nuclear magnetic resonance metabolomics. Clusters were obtained based on metabolites using 4 different unsupervised clustering methods: k-means (KM), partitioning around medoids (PAM), self-organizing maps (SOM), and hierarchical agglomerative clustering (HAC). The t-test, χ2 test, and Fisher’s exact test were used to compare sociodemographic, lifestyle, clinical, and dietary characteristics across the clusters. P-values were adjusted through a false discovery rate (FDR). RESULTS: Two clusters were identified using the 4 methods. Participants in cluster 2 had lower concentrations of apolipoprotein A1 and large high-density lipoprotein (HDL) particles and smaller HDL particle sizes, but higher concentrations of chylomicrons and extremely large very-low-density-lipoprotein (VLDL) particles and glycoprotein acetyls, a higher ratio of monounsaturated fatty acids to total fatty acids, and larger VLDL particle sizes compared with cluster 1. Body mass index was significantly higher in cluster 2 compared with cluster 1 (FDR adjusted-PKM < 0.001; PPAM = 0.001; PSOM < 0.001; and PHAC = 0.043). CONCLUSION The breast cancer survivors clustered on the basis of plasma metabolites had distinct characteristics. Further prospective studies are needed to investigate the associations between metabolites, obesity, dietary factors, and breast cancer prognosis.

BACKGROUND/OBJECTIVES: Isoflavones are estrogen-like compounds found in plants and their health effects remain equivocal. We investigated dietary isoflavone intake and its associated factors in Korean breast cancer survivors, with a comparison to cancer-free women. SUBJECTS/METHODS: The usual dietary intake of breast cancer survivors (n = 981, mean age 52 yrs) in 9 hospitals between 2012 and 2019 was assessed using 3-day food records or food frequency questionnaires (FFQs). They were age-matched to 2,943 cancer-free women who completed FFQs as part of a nationwide study conducted between 2012 and 2016. We used the flavonoid database of common Korean foods and the Phenol-Explorer database to estimate isoflavone intake. The contribution of each food or food group to the total isoflavone intake was calculated. The adjusted least-squares means of dietary isoflavone intake according to lifestyle and clinical factors were calculated using generalized linear models. RESULTS: Breast cancer survivors had a higher mean dietary isoflavone intake (23.59 mg/day) than cancer-free women (17.81 mg/day). Major food sources, including tofu, soybeans, and doenjang, contributed to over 70% of the isoflavone intake in both groups. When we estimated dietary isoflavone intake according to lifestyle characteristics, isoflavone intake increased with higher scores of adherence to the American Cancer Society dietary guidelines but decreased with increasing body mass index in both groups. Among cancer-free women, dietary isoflavone intake was higher among those who had never smoked and among dietary supplement users. Among breast cancer survivors, dietary isoflavone intakes did not vary with clinical characteristics, including time since surgery and estrogen receptor status. CONCLUSION Breast cancer survivors were more likely to consume isoflavones than agematched cancer-free women. Dietary isoflavone intake was associated with healthy lifestyle characteristics in women both with and without breast cancer. Further research is needed to understand the role of the higher isoflavone intake among breast cancer survivors compared to cancer-free women on their prognosis.

Purpose: Adjuvant treatment for craniopharyngioma after surgery is controversial. Adjuvant external beam radiation therapy (EBRT) can increase the risk of long-term sequelae. Stereotactic radiosurgery (SRS) is used to reduce treatment-related toxicity.In this study, we compared the treatment outcomes and toxicities of adjuvant therapies for craniopharyngioma. Materials and Methods: We analyzed patients who underwent craniopharyngioma tumor removal between 2000 and 2017. Of the 153 patients, 27 and 20 received adjuvant fractionated EBRT and SRS, respectively. We compared the local control (LC), progression-free survival (PFS), and overall survival between groups that received adjuvant fractionated EBRT, SRS, and surveillance. Results: The median follow-up period was 77.7 months. For SRS and surveillance, the 10-year LC was 57.2% and 57.4%, respectively. No local progression was observed after adjuvant fractionated EBRT. One patient in the adjuvant fractionated EBRT group died owing to glioma 94 months after receiving radiotherapy (10-year PFS: 80%). The 10-year PFS was 43.6% and 50.7% in the SRS and surveillance groups, respectively. The treatment outcomes significantly differed according to adjuvant treatment in nongross total resection (GTR) patients. Additional treatment-related toxicity was comparable in the adjuvant fractionated EBRT and other groups. Conclusion Adjuvant fractionated EBRT could be effective in controlling local failure, especially in patients with non-GTR, while maintaining acceptable treatment-related toxicity.

Background and Objectives: Cigarette smoking is a major risk factor for atherosclerosis.Nicotine, a crucial constituent of tobacco, contributes to atherosclerosis development and progression. However, evidence of the association between nicotine and neointima formation is limited. We aimed to evaluate whether nicotine enhances neointimal hyperplasia in the native epicardial coronary arteries of pigs after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Methods: After coronary angiography (CAG) and quantitative coronary angiography (QCA), we implanted 20 DES into 20 pigs allocated to 2 groups: no-nicotine (n=10) and nicotine (n=10) groups. Post-PCI CAG and QCA were performed immediately. Follow-up CAG, QCA, optical coherence tomography (OCT), and histopathological analyses were performed 2 months post-PCI. Results: Despite intergroup similarities in the baseline QCA findings, OCT analysis showed that the nicotine group had a smaller mean stent and lumen areas, a larger mean neointimal area, greater percent area stenosis, and higher peri-strut fibrin and inflammation scores than the no-nicotine group. In immunofluorescence analysis, the nicotine group displayed higher expression of CD68 and α-smooth muscle actin but lower CD31 expression than the no-nicotine group. Conclusions Nicotine inhibited re-endothelialization and promoted inflammation and NIH after PCI with DES in a porcine model.

Purpose: Breast cancer gene (BRCA) mutation is a well-known risk factor for breast cancer, and clinical interest in prophylactic mastectomy has increased in recent years.We investigated patients who were BRCA mutation carriers and underwent contralateral risk-reducing mastectomy (RRM), focusing on the incidence of occult malignancy after contralateral RRM. Methods: Prospectively collected data of patients with breast cancer treated at a single institution were retrospectively reviewed. Patients who underwent RRM with BRCA mutation who underwent RRM between January 2010 and November 2023 were included in this study.Among patients who underwent contralateral RRM, those with a primary cancer diagnosis were included, and those with occult malignancy on the contralateral RRM side were reviewed additionally. The demographics and pathologies of both primary breast cancer and occult malignancies were evaluated. Results: In our institution, 925 patients were identified as BRCA mutation carriers, and 320 patients underwent contralateral RRM along with primary breast cancer surgery. BRCA2 mutation occurred more frequently (54.8%) in the overall BRCA mutation cohort. Furthermore, we reviewed 320 patients diagnosed with breast cancer and detected as BRCA mutation carriers who underwent contralateral RRM; high proportion of them were BRCA1 mutation carriers.Interestingly, we found a low incidence of only seven patients (2.2%) with occult malignancy on contralateral RRM side, which is different from that reported in other nations. Conclusion The incidence of occult malignancy in the contralateral breast of breast cancer patients with breast cancer with BRCA mutation is significantly low, and may be influenced by several factors. Increased utilization of screening and advancements in diagnostic technologies in South Korea have reduced the chance of occult malignancy in RRM, and a variety of pathologic examination methods may affect the rate of incidence.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.