1.The Korean Rectal Cancer Multidisciplinary Committee Clinical Practice Guidelines for Rectal Cancer version 2.0
Hyo Seon RYU ; Hyun Jung KIM ; Dong Hyun KANG ; Yoo-Kang KWAK ; Han Deok KWAK ; Yoon-Hye KWON ; Dalyon KIM ; Baek-Hui KIM ; Jae Hyun KIM ; Ji Hun KIM ; Jin Won KIM ; Tae Hyung KIM ; Hae Young KIM ; Soo Min NAM ; Gyoung Tae NOH ; Jun Woo BONG ; Nak Song SUNG ; Seon Hui SHIN ; Kil-Yong LEE ; Sung Chul LEE ; Sea-Won LEE ; Jung Won LEE ; Jong Min LEE ; Myung Hoon IHN ; Joo Han LIM ; Woong Bae JI ; Dae Hee PYO ; Young Ki HONG ; Jung-Myun KWAK ;
Annals of Coloproctology 2026;42(1):4-33
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.
2.Conventional machine learning-based prediction models did not outperform the International IgA Nephropathy Prediction Tool
Sehoon PARK ; Yisak KIM ; Chung Hee BAEK ; Hyunjeong CHO ; Ji In PARK ; Eun Sil KOH ; Jung Pyo LEE ; Sun-Hee PARK ; Hyung Woo KIM ; Seung Hyeok HAN ; Ho Jun CHIN ; Dong Ki KIM ; Kyung Chul MOON ; Young-Gon KIM ; Hajeong LEE
Kidney Research and Clinical Practice 2025;44(5):802-813
Immunoglobulin A nephropathy (IgAN) is a major cause of end-stage kidney disease (ESKD). The International IgA Nephropathy Prediction Tool (IIgAN-PT) predicts IgAN prognosis, but improvement in the prediction performance using machine learning (ML)-based methods is needed. Methods: We analyzed 4,425 biopsy-confirmed patients with IgAN and ≥6 months of follow-up from nine tertiary university hospitals in Korea. The study population was divided into development and validation cohorts. Using the collected 87 clinicodemographic and pathological variables, ML-based prediction models for ESKD or estimated glomerular filtration rate decline (50% reduction or <15 mL/min/1.73 m2 ) were constructed: 1) the conventional CatBoost model, 2) the optimized CatBoost model with Cox proportional hazards, 3) the deep Cox proportional hazards model, and 4) the deep Cox mixture model. The area under the curve (AUC) and calibration plots were used to investigate the discriminative and calibration performance of the models, which were then compared with those of the IIgAN-PT full model. Results: The full model showed excellent performance (AUC [95% confidence interval] for 5-year outcome, 0.896 [0.853–0.940]), with acceptable calibration results. The ML-based models showed good performance in predicting adverse kidney outcomes and revealed acceptable discrimination performance in the external validation (AUC [95% confidence interval] for the 5-year outcome: 1) 0.829 [0.791–0.866]; 2) 0.847 [0.804–0.890]; 3) 0.823 [0.784–0.862]; and 4) 0.832 [0.794–0.870]), although the models showed underestimation in calibration analysis of the external validation cohort. With the validation data, the overall performance of the IIgAN-PT was non-inferior to that of the ML-based model. Conclusions: Our ML-based models showed good performance in predicting adverse kidney outcomes in patients with IgAN but they did not outperform the IIgAN-PT.
3.Designing a user-centered mobile health application to empower older adults in managing oral health lifestyle
Hye-Sun SHIN ; Seung-Pyo LEE ; Yuyi PARK ; You-Bin YIM ; Dong-Hun HAN
Journal of Korean Academy of Oral Health 2025;49(4):205-211
Objectives:
This study aimed to develop an age-friendly oral health lifestyle service application to enhance older adults’ self-management and promote a prevention-oriented approach to oral health. The application integrates user-centered design principles and the Capability, Opportunity, Motivation, and Behavior (COM-B) behavioral change theory to mitigate oral function decline and the digital divide.
Methods:
The application was developed based on three principles: (1) user-centered design, reflecting the physical and cognitive characteristics of older adults with large fonts, high-contrast colors, intuitive icons, and simplified navigation; (2) behavioral change theory (COM-B model), enhancing capability, opportunity, and motivation through educational content, mobile accessibility, and feedback using self-monitoring and goal setting; and (3) a prevention-oriented approach, aligned with the WHO Global Oral Health Action Plan. The system included four modules: (1) a 16-item self-assessment across five oral health domains, (2) a three-level risk classification with visual feedback (green/yellow/red), (3) a personalized education module with multimedia content, and (4) a habit-formation tool that supported self-monitoring and reminders.
Results:
An Android-based prototype was developed with four menus: self-assessment, feedback, education, and habit formation. The self-assessment tool classified users into low-, moderate-, and high-risk groups and provided motivational feedback. Based on the results, stage-specific educational videos and motivational cues were delivered as alerts. Senior-friendly UI/UX features such as large text, high contrast, intuitive icons, and tactile feedback enhanced accessibility and usability. Overall, the prototype integrated oral frailty assessment with theory-based interventions, fostering self-efficacy and engagement in preventive oral healthcare.
Conclusions
The application provides an accessible theory-based digital solution that empowers older adults to manage their oral health and prevent frailty. This presents a promising model for shifting oral health care to self-care and prevention. Future studies will use surveys and log data to examine the relationships among usage, usefulness, usability, acceptance, and behavior change. A randomized controlled trial is required to verify the effectiveness of this application.
4.Mutation-Driven Immune Microenvironments in Non-Small Cell Lung Cancer: Unrevealing Patterns through Cluster Analysis
Youngtaek KIM ; Joon Yeon HWANG ; Kwangmin NA ; Dong Kwon KIM ; Seul LEE ; Seong-san KANG ; Sujeong BAEK ; Seung Min YANG ; Mi Hyun KIM ; Heekyung HAN ; Seong Su JEONG ; Chai Young LEE ; Yu Jin HAN ; Jie-Ohn SOHN ; Sang-Kyu YE ; Kyoung-Ho PYO
Yonsei Medical Journal 2024;65(12):683-694
Purpose:
We aimed to comprehensively analyze the immune cell and stromal components of tumor microenvironment at the single-cell level and identify tumor heterogeneity among the major top-derived oncogene mutations in non-small cell lung cancer (NSCLC) using single-cell RNA sequencing (scRNA-seq) data.
Materials and Methods:
The scRNA-seq dataset utilized in this study comprised 64369 primary tumor tissue cells from 21 NSCLC patients, focusing on mutations in EGFR, ALK, BRAF, KRAS, TP53, and the wild-type.
Results:
Tumor immune microenvironment (TIM) analysis revealed differential immune responses across NSCLC mutation subtypes. TIM analysis revealed different immune responses across the mutation subtypes. Two mutation clusters emerged: KRAS, TP53, and EGFR+TP53 mutations (MC1); and EGFR, BRAF, and ALK mutations (MC2). MC1 showed higher tertiary lymphoid structures signature scores and enriched populations of C2-T-IL7R, C3-T/NK-CXCL4, C9-T/NK-NKG, and C1-B-MS4A1 clusters than cluster 2. Conversely, MC2 cells exhibited higher expression levels of TNF, IL1B, and chemokines linked to alternative immune pathways. Remarkably, co-occurring EGFR and TP53 mutations were grouped as MC1. EGFR+TP53 mutations showed upregulation of peptide synthesis and higher synthetic processes, as well as differences in myeloid and T/NK cells compared to EGFR mutations. In T/NK cells, EGFR+TP53 mutations showed a higher expression of features related to cell activity and differentiation, whereas EGFR mutations showed the opposite.
Conclusion
Our research indicates a close association between mutation types and tumor microenvironment in NSCLC, offering insights into personalized approaches for cancer diagnosis and treatment.
5.p27 Cell Cycle Inhibitor and Survival in Luminal-Type Breast Cancer:Gene Ontology, Machine Learning, and Drug Screening Analysis
In Ah PARK ; Yung-Kyun NOH ; Kyueng-Whan MIN ; Dong-Hoon KIM ; Jeong-Yeon LEE ; Byoung Kwan SON ; Mi Jung KWON ; Myung-Hoon HAN ; Joon Young HUR ; Jung Soo PYO
Journal of Breast Cancer 2024;27(5):305-322
Purpose:
A widely distributed cell cycle inhibitor, p27, regulates cyclin-dependent kinase-cyclin complexes. Although the prognostic value of p27 has been established for various types of carcinomas, its role in luminal breast cancer remains poorly understood. This study aimed to explore the functional enrichment of p27 and identify potential drug targets in patients with luminal-type breast cancer.
Methods:
Clinicopathological data were collected from 868 patients with luminal-type breast cancer. Additionally, publicly available data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset (1,500 patients) and the Gene Expression Omnibus database (855 patients) were included in the analysis. Immunohistochemical staining for p27, differential gene expression analysis, disease ontology analysis, survival prediction modeling using machine learning (ML), and in vitro drug screening were also performed.
Results:
Low p27 expression correlated with younger age, advanced tumor stage, estrogen receptor/progesterone receptor negativity, decreased cluster of differentiation 8+ T cell count, and poorer survival outcomes in luminal-type breast cancer. The METABRIC data revealed that reduced cyclin-dependent kinase inhibitor 1B (CDKN1B) expression (encoding p27) was associated with cell proliferation-related pathways and epigenetic polycomb repressive complex 2. Using ML, p27 emerged as the second most significant survival factor after N stage, thereby enhancing survival model performance. Additionally, luminal-type breast cancer cell lines with low CDKN1B expression demonstrated increased sensitivity to specific anticancer drugs such as voxtalisib and serdemetan, implying a potential therapeutic synergy between CDKN1B-targeted approaches and these drugs.
Conclusion
The integration of ML and bioinformatic analyses of p27 has the potential to enhance risk stratification and facilitate personalized treatment strategies for patients with breast cancer.
6.Mutation-Driven Immune Microenvironments in Non-Small Cell Lung Cancer: Unrevealing Patterns through Cluster Analysis
Youngtaek KIM ; Joon Yeon HWANG ; Kwangmin NA ; Dong Kwon KIM ; Seul LEE ; Seong-san KANG ; Sujeong BAEK ; Seung Min YANG ; Mi Hyun KIM ; Heekyung HAN ; Seong Su JEONG ; Chai Young LEE ; Yu Jin HAN ; Jie-Ohn SOHN ; Sang-Kyu YE ; Kyoung-Ho PYO
Yonsei Medical Journal 2024;65(12):683-694
Purpose:
We aimed to comprehensively analyze the immune cell and stromal components of tumor microenvironment at the single-cell level and identify tumor heterogeneity among the major top-derived oncogene mutations in non-small cell lung cancer (NSCLC) using single-cell RNA sequencing (scRNA-seq) data.
Materials and Methods:
The scRNA-seq dataset utilized in this study comprised 64369 primary tumor tissue cells from 21 NSCLC patients, focusing on mutations in EGFR, ALK, BRAF, KRAS, TP53, and the wild-type.
Results:
Tumor immune microenvironment (TIM) analysis revealed differential immune responses across NSCLC mutation subtypes. TIM analysis revealed different immune responses across the mutation subtypes. Two mutation clusters emerged: KRAS, TP53, and EGFR+TP53 mutations (MC1); and EGFR, BRAF, and ALK mutations (MC2). MC1 showed higher tertiary lymphoid structures signature scores and enriched populations of C2-T-IL7R, C3-T/NK-CXCL4, C9-T/NK-NKG, and C1-B-MS4A1 clusters than cluster 2. Conversely, MC2 cells exhibited higher expression levels of TNF, IL1B, and chemokines linked to alternative immune pathways. Remarkably, co-occurring EGFR and TP53 mutations were grouped as MC1. EGFR+TP53 mutations showed upregulation of peptide synthesis and higher synthetic processes, as well as differences in myeloid and T/NK cells compared to EGFR mutations. In T/NK cells, EGFR+TP53 mutations showed a higher expression of features related to cell activity and differentiation, whereas EGFR mutations showed the opposite.
Conclusion
Our research indicates a close association between mutation types and tumor microenvironment in NSCLC, offering insights into personalized approaches for cancer diagnosis and treatment.
7.p27 Cell Cycle Inhibitor and Survival in Luminal-Type Breast Cancer:Gene Ontology, Machine Learning, and Drug Screening Analysis
In Ah PARK ; Yung-Kyun NOH ; Kyueng-Whan MIN ; Dong-Hoon KIM ; Jeong-Yeon LEE ; Byoung Kwan SON ; Mi Jung KWON ; Myung-Hoon HAN ; Joon Young HUR ; Jung Soo PYO
Journal of Breast Cancer 2024;27(5):305-322
Purpose:
A widely distributed cell cycle inhibitor, p27, regulates cyclin-dependent kinase-cyclin complexes. Although the prognostic value of p27 has been established for various types of carcinomas, its role in luminal breast cancer remains poorly understood. This study aimed to explore the functional enrichment of p27 and identify potential drug targets in patients with luminal-type breast cancer.
Methods:
Clinicopathological data were collected from 868 patients with luminal-type breast cancer. Additionally, publicly available data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset (1,500 patients) and the Gene Expression Omnibus database (855 patients) were included in the analysis. Immunohistochemical staining for p27, differential gene expression analysis, disease ontology analysis, survival prediction modeling using machine learning (ML), and in vitro drug screening were also performed.
Results:
Low p27 expression correlated with younger age, advanced tumor stage, estrogen receptor/progesterone receptor negativity, decreased cluster of differentiation 8+ T cell count, and poorer survival outcomes in luminal-type breast cancer. The METABRIC data revealed that reduced cyclin-dependent kinase inhibitor 1B (CDKN1B) expression (encoding p27) was associated with cell proliferation-related pathways and epigenetic polycomb repressive complex 2. Using ML, p27 emerged as the second most significant survival factor after N stage, thereby enhancing survival model performance. Additionally, luminal-type breast cancer cell lines with low CDKN1B expression demonstrated increased sensitivity to specific anticancer drugs such as voxtalisib and serdemetan, implying a potential therapeutic synergy between CDKN1B-targeted approaches and these drugs.
Conclusion
The integration of ML and bioinformatic analyses of p27 has the potential to enhance risk stratification and facilitate personalized treatment strategies for patients with breast cancer.
8.Local Ablation for Hepatocellular Carcinoma: 2024Expert Consensus-Based Practical Recommendations of the Korean Liver Cancer Association
Seungchul HAN ; Pil Soo SUNG ; Soo Young PARK ; Jin Woong KIM ; Hyun Pyo HONG ; Jung-Hee YOON ; Dong Jin CHUNG ; Joon Ho KWON ; Sanghyeok LIM ; Jae Hyun KIM ; Seung Kak SHIN ; Tae Hyung KIM ; Dong Ho LEE ; Jong Young CHOI ; Research Committee of the Korean Liver Cancer Association
Korean Journal of Radiology 2024;25(9):773-787
Local ablation for hepatocellular carcinoma (HCC), a non-surgical option that directly targets and destroys tumor cells, has advanced significantly since the 1990s. Therapies with different energy sources, such as radiofrequency ablation, microwave ablation, and cryoablation, employ different mechanisms to induce tumor necrosis. The precision, safety, and effectiveness of these therapies have increased with advances in guiding technologies and device improvements. Consequently, local ablation has become the first-line treatment for early-stage HCC. The lack of organized evidence and expert opinions regarding patient selection, pre-procedure preparation, procedural methods, swift post-treatment evaluation, and follow-up has resulted in clinicians following varied practices. Therefore, an expert consensus-based practical recommendation for local ablation was developed by a group of experts in radiology and hepatology from the Research Committee of the Korean Liver Cancer Association in collaboration with the Korean Society of Image-guided Tumor Ablation to provide useful information and guidance for performing local ablation and for the pre- and post-treatment management of patients.
9.p27 Cell Cycle Inhibitor and Survival in Luminal-Type Breast Cancer:Gene Ontology, Machine Learning, and Drug Screening Analysis
In Ah PARK ; Yung-Kyun NOH ; Kyueng-Whan MIN ; Dong-Hoon KIM ; Jeong-Yeon LEE ; Byoung Kwan SON ; Mi Jung KWON ; Myung-Hoon HAN ; Joon Young HUR ; Jung Soo PYO
Journal of Breast Cancer 2024;27(5):305-322
Purpose:
A widely distributed cell cycle inhibitor, p27, regulates cyclin-dependent kinase-cyclin complexes. Although the prognostic value of p27 has been established for various types of carcinomas, its role in luminal breast cancer remains poorly understood. This study aimed to explore the functional enrichment of p27 and identify potential drug targets in patients with luminal-type breast cancer.
Methods:
Clinicopathological data were collected from 868 patients with luminal-type breast cancer. Additionally, publicly available data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset (1,500 patients) and the Gene Expression Omnibus database (855 patients) were included in the analysis. Immunohistochemical staining for p27, differential gene expression analysis, disease ontology analysis, survival prediction modeling using machine learning (ML), and in vitro drug screening were also performed.
Results:
Low p27 expression correlated with younger age, advanced tumor stage, estrogen receptor/progesterone receptor negativity, decreased cluster of differentiation 8+ T cell count, and poorer survival outcomes in luminal-type breast cancer. The METABRIC data revealed that reduced cyclin-dependent kinase inhibitor 1B (CDKN1B) expression (encoding p27) was associated with cell proliferation-related pathways and epigenetic polycomb repressive complex 2. Using ML, p27 emerged as the second most significant survival factor after N stage, thereby enhancing survival model performance. Additionally, luminal-type breast cancer cell lines with low CDKN1B expression demonstrated increased sensitivity to specific anticancer drugs such as voxtalisib and serdemetan, implying a potential therapeutic synergy between CDKN1B-targeted approaches and these drugs.
Conclusion
The integration of ML and bioinformatic analyses of p27 has the potential to enhance risk stratification and facilitate personalized treatment strategies for patients with breast cancer.
10.Exploring the Expression and Function of T Cell Surface Markers Identified through Cellular Indexing of Transcriptomes and Epitopes by Sequencing
Joon Yeon HWANG ; Youngtaek KIM ; Kwangmin NA ; Dong Kwon KIM ; Seul LEE ; Seong-san KANG ; Sujeong BAEK ; Seung Min YANG ; Mi Hyun KIM ; Heekyung HAN ; Seong Su JEONG ; Chai Young LEE ; Yu Jin HAN ; Jie-Ohn SOHN ; Sang-Kyu YE ; Kyoung-Ho PYO
Yonsei Medical Journal 2024;65(9):544-555
Purpose:
By utilizing both protein and mRNA expression patterns, we can identify more detailed and diverse immune cells, providing insights into understanding the complex immune landscape in cancer ecosystems.
Materials and Methods:
This study was performed by obtaining publicly available Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) data of peripheral blood mononuclear cells (PBMCs) from the Gene Expression Omnibus database. A total of 94674 total cells were analyzed, of which 32412 were T cells. There were 228 protein features and 16262 mRNA features in the data.The Seurat package was used for quality control and preprocessing, principal component analysis was performed, and Uniform Manifold Approximation and Projection was used to visualize the clusters. Protein and mRNA levels in the CITE-seq were analyzed.
Results:
We observed that a subset of T cells in the clusters generated at the protein level divided better. By identifying mRNA markers that were highly correlated with the CD4 and CD8 proteins and cross-validating CD26 and CD99 markers using flow cytometry, we found that CD4 + and CD8+ T cells were better discriminated in PBMCs. Weighted Nearest Neighbor clustering results identified a previously unobserved T cell subset.
Conclusion
In this study, we used CITE-seq data to confirm that protein expression patterns could be used to identify cells more precisely. These findings will improve our understanding of the heterogeneity of immune cells in the future and provide valuable insights into the complexity of the immune response in health and disease.

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