1.HER2-low and ultralow breast cancer: interobserver challenges and lessons from a consensus study
Jiwon KOH ; Yoon Jin CHA ; Eun Yoon CHO ; Ahwon LEE ; Ja Seung KOO ; So Yeon PARK ; Min Hwan KIM ; Jae Ho JEONG ; Gyungyub GONG
Journal of Pathology and Translational Medicine 2026;60(3):331-337
The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.
2.Long-Term Pulmonary Function and Radiologic Abnormalities Up to 3 Years After COVID-19:A Systematic Review and Meta-Analysis
Jiyoung SONG ; Jong Hyuk LEE ; Hyungin PARK ; Myoung-Jin JANG ; Soon Ho YOON
Korean Journal of Radiology 2026;27(2):174-185
Objective:
To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors.
Materials and Methods:
A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings.
Results:
In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%–40% (P = 0.14).The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%–47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts.
Conclusion
DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.
3.Development of an artificial intelligence-based prediction platform for early recurrence of resectable pancreatic cancer after curative surgery–toward future use as an indication for neoadjuvant treatment: a retrospective multicenter cohort study
So Jeong YOON ; Sung Hyun KIM ; Hongbeom KIM ; Sang Hyun SHIN ; Jin Seok HEO ; Seung Soo HONG ; Chang Moo KANG ; Kyung Sik KIM ; Ho Kyoung HWANG ; In Woong HAN
Annals of Surgical Treatment and Research 2026;110(2):76-83
Purpose:
Neoadjuvant treatment (NAT) is now the standard for borderline resectable pancreatic cancer (RPC) and is being considered for RPC. Early recurrence after curative surgery in RPC is often seen as a treatment failure, prompting considerations for NAT. Our goal was to develop an artificial intelligence (AI)-based predictive model utilizing preoperatively available factors to forecast early recurrences of resected RPC.
Methods:
This study included 469 patients who underwent surgery for RPC between 2011 and 2019. Clinicopathologic and oncologic data were retrospectively reviewed. Preoperative variables, including laboratory data and imaging findings, were collected. Early recurrence was defined as recurrence occurring within a year after surgery. Deep neural networks were then used to select variables by assessing their importance. A new model predicting early recurrence of RPC was subsequently developed.
Results:
Of the patients evaluated, 199 (42.4%) experienced early recurrence. The predictive model included 14 preoperative variables: CA 19-9, preoperative pancreatitis, serum albumin, platelet count, lymphocyte count, the American Society of Anesthesiologists physical status classification, tumor size, monocyte count, age, body mass index, CRP, hemoglobin, WBC count, and CEA. The area under the curve for the model was 0.786 in the training set and 0.734 in the test set.
Conclusion
We developed an AI-based model to predict the early recurrence of RPC using preoperative parameters. By identifying patients at risk of early recurrence, optimal individualized treatments such as NAT can be considered. Future prospective studies are crucial to establish clear indications for NAT in RPC.
4.Non-operative Management of Rectal Cancer with Adjuvant Chemotherapy after Chemoradiotherapy (NORMANDY): Prospective Study
Hyebin LEE ; Hyung Ook KIM ; Jason Joon Bock LEE ; In-Gu DO ; Heon-Ju KWON ; Mi Sung KIM ; Soo-Kyung PARK ; Hyo-Joon YANG ; Yoon Suk JUNG ; Jung Ho PARK ; Dong-Il PARK ; Kyung Uk JUNG ; Eo Jin KIM ; Dong-Hoe KOO ; Hungdai KIM ; Ho-Kyung CHUN ;
Cancer Research and Treatment 2026;58(2):573-580
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.
5.Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric and Young Adult Patients with Chronic Myeloid Leukemia in Tyrosine Kinase Inhibitor Era: A Study of the Korean Blood and Marrow Transplantation Registry
Hee Young JU ; Hyoung Soo CHOI ; Hyeon Jin PARK ; Keon Hee YOO ; Chuhl Joo LYU ; Ho Joon IM ; Min Kyoung KIM ; Yeung-Chul MUN ; Joon Ho MOON ; Sung-Soo YOON ; Eunyoung LEE ; Jae Hoon LEE ; Je-Hwan LEE ; So Young CHONG ; June-Won CHEONG ; Seunghyun WON ;
Cancer Research and Treatment 2026;58(2):632-641
Purpose:
Chronic myeloid leukemia (CML) in children, adolescents, and young adults is rare and differs from older adults. This study evaluated the outcomes of allogeneic hematopoietic stem cell transplantation (HSCT) in young Korean CML patients during the tyrosine kinase inhibitor (TKI) era.
Materials and Methods:
A retrospective analysis of 35 CML patients aged < 40 years who underwent allogeneic HSCT from 2009 to 2019 was conducted using Korean Blood and Marrow Transplantation Registry data. Patients were grouped by age < 20 years at HSCT (group 1, n=15) and 20-40 years at HSCT (group 2, n=20). Survival outcomes including overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS) were analyzed using the Kaplan-Meier method.
Results:
The median time between diagnosis and HSCT was 8.9 months. All the patients achieved engraftment but platelet recovery was significantly slower in group 1 (p=0.034). Acute and chronic graft-versus-host disease occurred in 54.3% and 34.3%, respectively. Five-year OS, RFS, and EFS rates of total patients were 66.8%, 50.8%, and 47.6%, with better OS was observed in group 1 by multivariable analysis (p=0.048). Disease status at HSCT was a significant predictor of OS (p=0.028), RFS (p=0.003), and EFS (p=0.004). Disease progression occurred in 13 out of 35 patients (37.1%); treatment-related mortality accounted for 63.6% of deaths (7 out of 11).
Conclusion
When performed at a younger age, allogeneic HSCT result in superior outcome in CML. Achieving remission before HSCT is critical for improved outcomes, highlighting the importance of pretransplant remission via optimal TKI strategies and minimal residual disease monitoring.
6.Detection Ability of Quality of Life Changes and Responsiveness of the KOQUSS-40 and the EORTC QLQ-C30/STO22 in Patients Who Underwent Gastrectomy: A Prospective Comparative Study
Bang Wool EOM ; Keun Won RYU ; Ji Yeong AN ; Yun-Suhk SUH ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In-Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye-Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Joongyub LEE ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2026;58(1):221-231
Purpose:
The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ).
Materials and Methods:
A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire.
Results:
Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ.
Conclusion
KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.
7.Spatial Transcriptomic Landscape of Brain Metastases from Triple-Negative Breast Cancer: Comparison of Primary Tumor and Brain Metastases Using Spatial Analysis
Jihwan YOO ; Inho PARK ; Hyun Jung KIM ; Hun Ho PARK ; Sora LEE ; Jee Hung KIM ; Yoon Jin CHA
Cancer Research and Treatment 2026;58(1):182-197
Purpose:
Triple-negative breast cancer (TNBC) is a particularly aggressive subtype of breast cancer, with approximately 30% of patients eventually developing brain metastases (BM), which result in poor outcomes. An understanding of the tumor microenvironment (TME) at both primary and metastatic sites offers insights into the mechanisms underlying BM and potential therapeutic targets.
Materials and Methods:
Spatial RNA sequencing (spRNA-seq) was performed on primary TNBC and paired BM tissues from three patients, one of whom had previously received immune checkpoint inhibitors before BM diagnosis. Specimen regions were categorized into tumor, proximal, and distal TME based on their spatial locations. Gene expression differences across these zones were analyzed, and immune cell infiltration was estimated using TIMER. A gene module analysis was conducted to identify key gene clusters associated with BM.
Results:
Distinct gene expression profiles were noted in the proximal and distal TMEs. In BM, the proximal TME exhibited neuronal gene expression, suggesting neuron-tumor interactions compared to tumor, and upregulation of epithelial genes compared to the distal TME. Immune cell analysis revealed dynamic changes in CD8+ T cells and macrophages across the tumor and TME zones. Gene module analysis identified five key modules, including one related to glycolysis, which correlated with patient survival. Drug repurposing analysis identified potential therapeutic targets, including VEGFA, RAC1, EGLN3, and CAMK1D.
Conclusion
This study provides novel insights into the transcriptional landscapes in TNBC BM using spRNA-seq, emphasizing the role of neuron-tumor interactions and immune dynamics. These findings suggest new therapeutic strategies and underscore the importance of further research.
8.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
9.Enriching Global Perspectives Through a Regional Lens: Recognition, Assessment, and Management of Tardive Dyskinesia in Southeast Asia
Roongroj BHIDAYASIRI ; Jin Kiat ANG ; Kok Yoon CHEE ; Roger HO ; Ahmad Shahir bin MAWARDI ; Adhi Wibowo NURHIDAYAT ; Pongsatorn PAHOLPAK ; Pornjira PARIWATCHARAKUL ; Thitima SANGUANVICHAIKUL ; Eng Khean UNG ; Natalia Dewi WARDANI ; Brian YEO
Journal of Movement Disorders 2026;19(1):11-18
10.Prosthetic rehabilitation of traumatized maxillary anterior teeth using a digital workflow: a case report
Jong-Hyun SHIN ; Sang-Ah LEE ; Lee-Ra CHO ; Chan-Jin PARK ; Kyung-Ho KO ; Yoon-Hyuk HUH
The Journal of Korean Academy of Prosthodontics 2026;64(1):84-94
The maxillary anterior region is critical for esthetics and function, requiring precise analysis and restoration when damaged by trauma. This case report presents the restorative process using a digital workflow for a patient with anterior trauma. A 22-year-old female exhibited fractures and extrusive luxation of maxillary central incisors, diagnosed with pulp necrosis. After endodontic treatment, intraoral and facial scans were performed, and provisional and definitive restorations were digitally designed. Various shade-matching techniques were employed to achieve natural esthetics. The definitive prosthesis improved harmony between the incisal edge and lower lip, as well as tooth axis, length, and zenith position, fulfilling the patient’s esthetic demands. This case suggests that combining digital technology and gingivectomy with a minimally invasive approach enables esthetic and functional restoration of the maxillary anterior region.

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