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.

Purpose: Atypical hyperplasia (AH) management remains controversial due to variable malignant disease progression rates. While Western studies report 10% to 25% upgrade rates, data from Asian populations, particularly from referral academic centers, are limited. We aimed to identify predictive factors for malignant upgrade in Korean women with AH at academic hospitals. Methods: This retrospective multi-institutional study analyzed 340 patients diagnosed with AH on initial biopsy who underwent subsequent excision at five Korean academic hospitals from 2000 to 2022. Malignant upgrade was defined as ductal carcinoma in situ or invasive cancer on the final pathology. Multivariate logistic regression was used to identify independent predictors of upgrades. Results: Among 340 patients (319 atypical ductal hyperplasia, 20 atypical lobular hyperplasia, and 1 mixed), 128 (37.6%) experienced a malignant upgrade, 98 (76.6%) to ductal carcinoma in situ, and 30 (23.4%) to invasive cancer. In multivariate analysis, multifocal atypia (odds ratio [OR], 25.61; 95% confidence interval [CI], 11.20–58.55; P<0.001) and Breast Imaging-Reporting and Data System 4c-5 lesions (OR, 11.02; 95% CI, 1.43–84.86; P=0.021) were significant predictors. Multifocal atypia showed an 84.4% upgrade rate. Core needle biopsy had higher upgrade rates than vacuum-assisted biopsy (45.2% vs. 20.0%; P<0.001). The upgrade rates decreased from 50% to 25% over the study period (P<0.05). Conclusion The 37.6% upgrade rate in this tertiary referral cohort exceeded that in Western reports, with multifocal atypia emerging as the strongest predictor. These findings support immediate excision for multifocal atypia while allowing individualized management for unifocal lesions with favorable imaging in Korean tertiary care settings.

Ovarian cancer remains one of the most lethal gynecologic malignancies, with limited responsiveness to standard chemotherapy and poor long-term prognosis. Tumor-associated macrophages, particularly M2-polarized populations, play a crucial role in immune suppression and tumor progression. Human induced pluripotent stem cells (hiPSCs) can differentiate into functional immune cells, providing an unlimited and patient-specific source for cell-based immunotherapy.In this study, we investigated the therapeutic potential of hiPSC-derived macrophages (hiMACs), specifically M1-polarized hiMACs, against ovarian cancer. In a co-culture system, M1-hiMACs significantly reduced the viability of ovarian cancer cells, inducing apoptosis and necrosis, whereas M0 macrophages showed minimal effects. In vivo, intravenous administration of M1-hiMACs into nude mice bearing ovarian cancer cells resulted in a dose-dependent reduction in tumor volume. Furthermore, combination therapy with paclitaxel and M1-hiMACs led to greater tumor regression and enhanced histological necrosis compared to either treatment alone. These findings demonstrate the potent anti-tumor effects of M1-hiMACs and highlight their potential for cellular immunotherapy for ovarian cancer, particularly in combination with chemotherapy.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Immunocompromised patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection often have prolonged viral shedding, and some are clinically suspected of reinfection with different SARSCoV-2 variants. However, data on this issue are limited. This study investigated the SARS-CoV-2 variants in serially collected respiratory samples from immunocompromised patients with prolonged viral shedding for over 12 weeks or relapsed viral shedding after at least 2 weeks of viral clearance. Materials and Methods: From February 2022 to September 2023, we prospectively enrolled immunocompromised patients with coronavirus disease 2019 who had hematologic malignancies or had undergone transplantation and were admitted to a tertiary hospital. Weekly saliva or nasopharyngeal swabs were collected from enrolled patients for at least 12 weeks after diagnosis. Genomic RNA polymerase chain reaction (PCR) was performed on samples, and those testing positive underwent viral culture to isolate the live virus. Spike gene full sequencing via Sanger sequencing and real-time reverse transcription-PCR for detecting mutation genes were conducted to identify SARSCoV-2 variants. Results: Among 116 enrolled patients, 20 with prolonged or relapsed viral shedding were screened to identify the variants. Of these 20 patients, 7 (35%) exhibited evidence of re-infection; one of 8 patients with prolonged viral shedding and 6 of 12 with relapsed viral shedding were reinfected with SARS-CoV-2. Conclusion Our data suggest that approximately one-third of immunocompromised patients with persistent or relapsed viral shedding had reinfection with different variants of SARS-CoV-2.

The common data model (CDM) has found widespread application in healthcare studies, but its utilization in cancer research has been limited. This article describes the development and implementation strategy for Cancer Clinical Library Databases (CCLDs), which are standardized cancer-specific databases established under the Korea-Clinical Data Utilization Network for Research Excellence (K-CURE) project by the Korean Ministry of Health and Welfare. Fifteen leading hospitals and fourteen academic associations in Korea are engaged in constructing CCLDs for 10 primary cancer types. For each cancer type-specific CCLD, cancer data experts determine key clinical data items essential for cancer research, standardize these items across cancer types, and create a standardized schema. Comprehensive clinical records covering diagnosis, treatment, and outcomes, with annual updates, are collected for each cancer patient in the target population, and quality control is based on six-sigma standards. To protect patient privacy, CCLDs follow stringent data security guidelines by pseudonymizing personal identification information and operating within a closed analysis environment. Researchers can apply for access to CCLD data through the K-CURE portal, which is subject to Institutional Review Board and Data Review Board approval. The CCLD is considered a pioneering standardized cancer-specific database, significantly representing Korea’s cancer data. It is expected to overcome limitations of previous CDMs and provide a valuable resource for multicenter cancer research in Korea.

Objectives: . Salivary gland tumors present a diagnostic challenge, with preoperative false-negative results frequently leading to an unexpected diagnosis of malignancy after parotidectomy. This study was conducted to explore the clinical utility of preoperative core needle biopsy (CNB) in diagnosing malignancies before primary parotidectomy and to assess the prognostic implications of CNB for parotid gland cancers. Methods: . This retrospective cohort study included 615 patients who underwent preoperative CNB and parotidectomy for primary parotid tumors from 2003 to 2023 at a tertiary referral hospital. Among these patients, 102 who were diagnosed with primary parotid malignancy following parotidectomy were examined regarding survival outcomes. Disease-free survival (DFS) and predictive factors were assessed through univariable and multivariable analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CNB were determined. These metrics were then compared to those of a separate cohort of 547 patients who underwent ultrasound-guided fine needle aspiration (FNA) and parotidectomy within the same timeframe. Results: . In the CNB group, the 5-year predicted DFS was 86.9% (95% CI, 79.2%–95.3%). Multivariable analysis identified male sex (hazard ratio [HR], 8.48; 95% CI, 1.05–68.76) and a CNB finding of malignancy (HR, 8.20; 95% CI, 1.01–66.15) as factors significantly associated with decreased DFS. CNB demonstrated significantly higher sensitivity (89.0%; 95% CI, 81.2%–94.4%) and NPV (97.6%; 95% CI, 95.7%–98.8%) compared to FNA, which had a sensitivity of 45.2% (95% CI, 33.5%–57.3%) and an NPV of 90.8% (95% CI, 87.7%–93.3%). Conclusion . Preoperative CNB may be predictive of parotid cancer prognosis. Patients receiving a diagnosis of malignancy on preoperative CNB demonstrated a worse prognosis compared to those with a “less-than-malignant” diagnosis. Additionally, CNB exhibited higher sensitivity than FNA in identifying malignancies of the parotid gland.

Background and Objectives: Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years. Results: There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults. Conclusion The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.

Background and Objectives: This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss. Results: The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults. Conclusion The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.