This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Purpose: While TP53 mutations are well known to be associated with adverse prognosis in hematological diseases, their functional impact remains incompletely understood. This study examines the spectrum of TP53 mutations across various hematologic malignancies and evaluates their functional impact. Materials and Methods: Using targeted sequencing panels, we analyzed TP53 mutations in the bone marrow aspiration samples of a retrospective cohort of 856 patients diagnosed with hematologic malignancies. To assess the impact of TP53 mutations, we applied the evolutionary action (EAp53) score and the relative fitness score (RFS), previously proposed functional scoring methods. The effects of variant allele frequency (VAF), disruptive mutations, EAp53 score, and RFS on overall survival (OS) were evaluated. Results: TP53 mutations were associated with inferior OS compared with wildtype TP53 (median OS 10.0 months versus not estimable; hazard ratio (HR) 4.6; p<0.001). In the acute myeloid leukemia, multiple myeloma, and myelodysplastic syndrome subgroups, TP53 mutations had a significant adverse impact on OS. (HRs 3.8, 4.2, 6.0, respectively; p<0.001, p=0.005, p<0.001, respectively). Patients with VAF >50% had significantly poorer OS compared to those with VAF ≤50% (median OS 7.5 months versus 22.8 months; HR 2.2, p=0.016). Moreover, patients in the high-risk RFS group (RFS >0.22) had significantly worse OS compared to those in the low-risk RFS group (RFS ≤0.22) (median OS 5.6 months versus 16.3 months; HR 2.2, p=0.041). However, no significant survival difference was observed between the EAp53 high-risk (>75) and low-risk (≤75) groups, or between patients with disruptive and non-disruptive mutations. Conclusion Our findings highlight VAF and RFS as valuable tools for stratifying TP53-mutant patients into high-risk and low-risk groups.

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.

Purpose: Many breast cancer patients experience genitourinary syndrome of menopause (GSM) symptoms. Concerns about systemic absorption limit the use of local estrogen therapy, and clinicians are often hesitant to prescribe it to breast cancer survivors.Therefore, other treatment options are essential. The aim of this study was to examine the safety and effectiveness of fractional CO2 laser treatment in breast cancer survivors experiencing GSM. Materials and Methods: Each woman received three fractional CO2 treatments at 4-week intervals between sessions: baseline (V1), 4-week follow-up (V2), 8-week follow-up (V3), and a final follow-up at 12 weeks (V4). Breast cancer survivors who had one or more symptoms related to GSM qualified for inclusion in this study. Severity of symptoms was assessed with a visual analog scale (VAS) at baseline and every follow-up visit. We also measured GSM objectively using the vaginal health index score (VHIS) at every visit. At V4, patients evaluated their satisfaction with laser therapy using a 5-point Likert scale. Results: Twenty-four women were included in the study. Almost all symptoms showed improvement based on mean VAS score after treatment. Vaginal dryness and urgency improved after the second treatment. After completion of all treatments, all symptoms except frequency showed improvement. VHIS increased significantly after completion of laser treatment (8.5±3.1 at baseline vs. 16.2±2.9 at V4; p<0.001). Conclusion Fractional CO2 laser treatment appears to be an effective and safe method in breast cancer survivors with GSM.

Endometriosis, a prevalent but debilitating condition affecting women, poses significant challenges in diagnosis and management. The current 2024 guideline, developed by the Korean Society of Endometriosis (KSE), builds upon the 2018 KSE guideline. This guideline aims to provide customized recommendations tailored to Korea’s unique clinical aspects and medical environment, and addresses key areas such as diagnosis, medical and surgical management, considerations for special populations, and its complex relationship with cancer.

Background: Histone deacetylase (HDAC) inhibition offers potential anticancer effects across diverse cancers due to HDAC's significant role in cancer development and progression. Consequently, we demonstrated the therapeutic efficacy of the novel HDAC inhibitor, CG-745, in comparison with existing inhibitors such as suberoylanilide hydroxamic acid (SAHA) in non-small cell lung cancer (NSCLC) cells. Methods: CG-745's effect on apoptosis and reactive oxygen species (ROS)-dependent mitochondrial dysfunction was investigated using annexin V assay, MitoSoX, and Western blot in human A549 and H460 cells. Additionally, HDAC expression was analyzed through real-time polymerase chain reaction. We also evaluated the inhibitory effect of CG-745 on epithelial-mesenchymal transition (EMT) induced by transforming growth factor β1 (TGF-β1) via Western blot, scratch analysis, and matrigel invasion analysis. Results: Compared to SAHA, CG-745 inhibited cell viability and mRNA expression of HDACs such as HDAC1, HDAC2, HDAC3, and HDAC8. It also induced apoptosis, ROS, and mitochondrial dysfunction in a concentration-dependent manner. CG-745 reversed EMT triggered by TGF-β1 in A549 and H460 cells, and curtailed the migration and invasion enhanced by TGF-β1. CG-745 has demonstrably inhibited EMT and induced apoptosis in NSCLC cells. Conclusion CG-745 may represent a novel therapeutic strategy for NSCLC treatment.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Background: Histone deacetylase (HDAC) inhibition offers potential anticancer effects across diverse cancers due to HDAC's significant role in cancer development and progression. Consequently, we demonstrated the therapeutic efficacy of the novel HDAC inhibitor, CG-745, in comparison with existing inhibitors such as suberoylanilide hydroxamic acid (SAHA) in non-small cell lung cancer (NSCLC) cells. Methods: CG-745's effect on apoptosis and reactive oxygen species (ROS)-dependent mitochondrial dysfunction was investigated using annexin V assay, MitoSoX, and Western blot in human A549 and H460 cells. Additionally, HDAC expression was analyzed through real-time polymerase chain reaction. We also evaluated the inhibitory effect of CG-745 on epithelial-mesenchymal transition (EMT) induced by transforming growth factor β1 (TGF-β1) via Western blot, scratch analysis, and matrigel invasion analysis. Results: Compared to SAHA, CG-745 inhibited cell viability and mRNA expression of HDACs such as HDAC1, HDAC2, HDAC3, and HDAC8. It also induced apoptosis, ROS, and mitochondrial dysfunction in a concentration-dependent manner. CG-745 reversed EMT triggered by TGF-β1 in A549 and H460 cells, and curtailed the migration and invasion enhanced by TGF-β1. CG-745 has demonstrably inhibited EMT and induced apoptosis in NSCLC cells. Conclusion CG-745 may represent a novel therapeutic strategy for NSCLC treatment.

Endometriosis, a prevalent but debilitating condition affecting women, poses significant challenges in diagnosis and management. The current 2024 guideline, developed by the Korean Society of Endometriosis (KSE), builds upon the 2018 KSE guideline. This guideline aims to provide customized recommendations tailored to Korea’s unique clinical aspects and medical environment, and addresses key areas such as diagnosis, medical and surgical management, considerations for special populations, and its complex relationship with cancer.

Endometriosis, a prevalent but debilitating condition affecting women, poses significant challenges in diagnosis and management. The current 2024 guideline, developed by the Korean Society of Endometriosis (KSE), builds upon the 2018 KSE guideline. This guideline aims to provide customized recommendations tailored to Korea’s unique clinical aspects and medical environment, and addresses key areas such as diagnosis, medical and surgical management, considerations for special populations, and its complex relationship with cancer.