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.

Background/Aims: Immune checkpoint inhibitors (ICIs) are effective in treating cancer. However, various immune-related adverse events (irAEs) have become prevalent, with ICI-induced colitis being the most common gastrointestinal irAE. Thus, we aimed to investigate the incidence and risk factors of ICI-induced colitis in Korean patients with cancer. Methods: This retrospective study included patients treated with ICIs between October 2015 and June 2022 in two tertiary referral centers in Daegu, Korea. The incidence of ICI-induced colitis was determined using electronic medical records. Risk factors for ICI-induced colitis were identified using univariate and multivariate logistic regression analyses. Results: We included 1,478 patients with ICI-treated cancer. The incidence of ICI-induced colitis was 3.5% (n = 52/1,478). Multivariate logistic regression analysis showed that the combination of nivolumab and ipilimumab was a risk factor for ICI-induced colitis (p = 0.006; odds ratio, 9.768; 95% confidence interval, 1.93–49.30). Conclusions ICI-induced colitis had an incidence rate of 3.5% and was associated with the combination of nivolumab and ipilimumab. Most patients with ICI-induced colitis developed mild symptoms that improved with supportive care alone, making ICI therapy resumption possible.

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.

Background/Aims: Immune checkpoint inhibitors (ICIs) are effective in treating cancer. However, various immune-related adverse events (irAEs) have become prevalent, with ICI-induced colitis being the most common gastrointestinal irAE. Thus, we aimed to investigate the incidence and risk factors of ICI-induced colitis in Korean patients with cancer. Methods: This retrospective study included patients treated with ICIs between October 2015 and June 2022 in two tertiary referral centers in Daegu, Korea. The incidence of ICI-induced colitis was determined using electronic medical records. Risk factors for ICI-induced colitis were identified using univariate and multivariate logistic regression analyses. Results: We included 1,478 patients with ICI-treated cancer. The incidence of ICI-induced colitis was 3.5% (n = 52/1,478). Multivariate logistic regression analysis showed that the combination of nivolumab and ipilimumab was a risk factor for ICI-induced colitis (p = 0.006; odds ratio, 9.768; 95% confidence interval, 1.93–49.30). Conclusions ICI-induced colitis had an incidence rate of 3.5% and was associated with the combination of nivolumab and ipilimumab. Most patients with ICI-induced colitis developed mild symptoms that improved with supportive care alone, making ICI therapy resumption possible.

Purpose: This study investigated the effects of a nursing leadership program on self-leadership, interpersonal relationships, clinical performance, problem-solving abilities, and nursing professionalism among nursing students in South Korea. Methods: A quasi-experimental study was conducted. The Practice-Driven Nursing Leadership Program for Students (PDNLP-S) was developed based on the ADDIE model (analysis, design, development, implementation, and evaluation). This quasi-experimental study design included 60 nursing students. The experimental group (n=30) participated in the PDNLP-S for 120-minute sessions over 5 weeks, while the control group (n=30) received usual lectures. The PDNLP-S included lectures, discussions, and individual and group activities to cultivate core nursing leadership competencies such as individual growth, collaboration, nursing excellence, creative problem-solving, and influence. Data were analyzed using descriptive statistics, the Mann-Whitney U-test, and the independent t-test with IBM SPSS Windows ver. 26.0. Results: The experimental group demonstrated significant improvements in self-leadership (t=3.28, p=.001), interpersonal relationships (t=3.07, p=.002), clinical performance (U=268.50, p=.004), and problem-solving abilities (t=2.20, p=.017) compared to the control group. No significant difference was observed in nursing professionalism (t=0.50, p=.311). Conclusion This study demonstrates that the PDNLP-S improved nursing students’ self-leadership, interpersonal relationships, clinical performance, and problem-solving abilities. The PDNLP-S can play a significant role in cultivating future nurse leaders by enhancing these nursing leadership competencies among nursing students.

Purpose: This study aimed to perform a genome characterization of Streptococcus mitis KHUD 011, a strain isolated from the oral microbiome of a healthy Korean individual, and to compare its genomic features with other S. mitis strains. Materials and Methods: The strain was identified through 16S rRNA gene sequencing, and its genome was sequenced using the PacBio Sequel II platform. De novo assembly and annotation were performed, followed by comparative genomic analysis with three additional strains (S. mitis NCTC 12261, S022-V3-A4, and B6). Pan-genome and phylogenetic analyses were conducted to identify strain-specific genes and assess inter-strain genomic diversity. Results: The genome of S. mitis KHUD 011 consisted of 1,782 protein-coding genes, with a G+C content of 40.24%. Pan-genome analysis identified 1,263 core gene clusters (50.0%), 496 dispensable clusters (19.7%), and 763 strain-specific clusters (30.3%). KHUD 011 displayed 88 strain-specific genes, particularly associated with cell wall/membrane biogenesis, transcriptional regulation, and carbohydrate metabolism. Phylogenetic analysis placed KHUD 011 closely with NCTC 12261, forming a distinct cluster apart from other strains. Conclusion The genome characterization of S. mitis KHUD 011 underscores substantial inter-strain genomic diversity influenced by host interactions, ecological niches, and health status. The identified strain-specific genes, particularly those associated with cell wall/ membrane biogenesis, transcriptional regulation, and carbohydrate metabolism, suggest adaptations to the oral microbiome and its interaction with the host. These findings highlight the ecological versatility of S. mitis and the importance of exploring strains from diverse environments to better understand their role within the host and the broader microbiome.