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: The triggering receptor expressed on myeloid cells 2 (TREM2) creates an immunosuppressive environment, but the effects of anticancer treatment on TREM2 and the tumor microenvironment (TME) are not well established. This study investigates the impact of chemotherapy on TREM2-expressing macrophages within the lung adenocarcinoma TME. Materials and Methods: Using single-cell RNA sequencing datasets of paired normal-appearing lung tissue (NL) and tumor (Tu), human and mouse lung cancer tissue, and THP-1 cells, we observed the effects of anticancer drugs on them. Results: Myeloid cells (MY) were the second-most abundant non-epithelial component in the Tu, though less prevalent than in NL. Specific MY subclusters abundant in Tu showed overexpression of TREM2. In lung cancer-induced Kras-G12D mice, M2 proportion increased in Tu compared to NL; cisplatin increased TREM2+ M2 proportion in Tu. TREM2+ cells in Tu showed interactions with cell clusters showing characteristics of interstitial macrophage such as mo-lineage, mono-Mc, and CD163/LGMN cells via FN:CD44 and MIF:CD74+CXCR4, suggesting that they influence the recruitment of those cells to Tu and TME reshape. In M0-state THP-1 cells, cisplatin and osimertinib treatments induced polarization towards M1 and M2 states and increased TREM2 expression. Cisplatin promoted uptake of phosphatidylserine-coated latex beads by M0 cells, whereas osimertinib reduced uptake by polarized macrophages. These findings suggest anticancer treatments impact the lung immune microenvironment by altering the TREM2+ cells. Conclusion Given TREM2’s central inhibitory role in the tumor immune environment, effects of chemotherapeutic agents should be considered in developing TREM2-targeting therapies.

Background: Living-donor liver transplantation (LDLT) is a viable alternative to deceased-donor liver transplantation. Enhanced recovery after surgery protocols that include early extubation offer short-term benefits; however, the effect of immediate extubation in the operating room (OR) on long-term outcomes in patients undergoing LDLT remains unknown. We hypothesized that immediate OR extubation is associated with improved long-term outcomes in patients undergoing LDLT. Methods: This retrospective cohort study included 205 patients who underwent LDLT. The patients were classified based on the extubation location as OREX (those extubated in the OR) or NOREX (those extubated in the intensive care unit [ICU]). The primary outcome was overall survival (OS), while secondary outcomes included ICU stay, hospital stay duration, and various postoperative outcomes. Results: Among the 205 patients, 98 (47.8%) underwent extubation in the OR after LDLT. Univariate analysis revealed that OR extubation did not significantly affect OS (hazard ratio [HR]: 0.50, 95% confidence interval [CI]: 0.24–1.05; P = 0.066). Furthermore, multivariate analysis revealed no statistically significant association between OR extubation and OS (HR: 0.79, 95% CI: 0.35–1.80; P = 0.580). However, OR extubation was significantly associated with a lower incidence of 30-day composite complications and shorter ICU and hospital stays. Multivariate analysis indicated that higher preoperative platelet counts, increased serum creatinine levels, and a longer surgery duration were associated with poorer OS. Conclusions Immediate OR extubation following LDLT surgery was associated with fewer 30-day composite complications and shorter ICU and hospital stays; however, it did not significantly improve OS compared with ICU extubation.

Purpose: This multicenter, open-label, phase II trial evaluated the efficacy and safety of bortezomib combined with dexamethasone for the treatment of relapsed/refractory cutaneous T-cell lymphoma (CTCL) in previously treated patients across 14 institutions in South Korea. Materials and Methods: Between September 2017 and July 2020, 29 patients with histologically confirmed CTCL received treatment, consisting of eight 4-week cycles of induction therapy followed by maintenance therapy, contingent upon response, for up to one year. The primary endpoint was the proportion of patients achieving an objective global response. Results: Thirteen of the 29 patients (44.8%) achieved an objective global response, including two complete responses. The median progression-free survival (PFS) was 5.8 months, with responders showing a median PFS of 14.0 months. Treatment-emergent adverse events were generally mild, with a low incidence of peripheral neuropathy and hematologic toxicities. Despite the trend toward shorter PFS in patients with higher mutation burdens, genomic profiling before and after treatment showed no significant emergence of new mutations indicative of disease progression. Conclusion This study supports the use of bortezomib and dexamethasone as a viable and safe treatment option for previously treated CTCL, demonstrating substantial efficacy and manageability in adverse effects. Further research with a larger cohort is suggested to validate these findings and explore the prognostic value of mutation profiles.

Purpose: In Korea, the Act on Hospice and Palliative Care and Decisions on Life-Sustaining Treatment (LST) was implemented on February 4, 2018. We aimed to investigate relevant factors and clinical changes associated with LST decisions after law enforcement. Materials and Methods: This single-center retrospective study included patients who completed LST documents using legal forms at Asan Medical Center from February 5, 2018, to June 30, 2020. Results: 5,896 patients completed LST documents, of which 2,704 (45.8%) signed the documents in person, while family members of 3,192 (54%) wrote the documents on behalf of the patients. Comparing first year and following year of implementation of the act, the self-documentation rate increased (43.9% to 47.2%, p=0.014). Moreover, the number of LST decisions made during or after intensive care unit admission decreased (37.8% vs. 35.2%, p=0.045), and the completion rate of LST documents during chemotherapy increased (6.6% vs. 8.9%, p=0.001). In multivariate analysis, age < 65 (odds ratio [OR], 1.724; 95% confidence interval [CI], 1.538 to 1.933; p < 0.001), unmarried status (OR, 1.309; 95% CI, 1.097 to 1.561; p=0.003), palliative care consultation (OR, 1.538; 95% CI, 1.340 to 1.765; p < 0.001), malignancy (OR, 1.864; 95% CI, 1.628 to 2.133; p < 0.001), and changes in timing on the first year versus following year (OR, 1.124; 95% CI, 1.003 to 1.260; p=0.045) were related to a higher self-documentation rate. Conclusion Age < 65 years, unmarried status, malignancy, and referral to a palliative care team were associated with patients making LST decisions themselves. Furthermore, the subject and timing of LST decisions have changed with the LST act.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Objective: : Palliative care is a specialized approach designed to enhance the quality of life for both patients and their families, offering patient-centered care through comprehensive assessment and care planning. However, the integration of palliative care within neurocritical care settings has been relatively understudied. This descriptive study aims to identify the characteristics, palliative care needs, and outcomes of patients referred to palliative care services during admission to the neurosurgical intensive care unit (NS-ICU). Methods: : A retrospective analysis of adults admitted to the NS-ICU at a referral hospital between December 2019 and December 2021 was conducted. The study focused on those referred to the inpatient palliative care team with diagnoses of non-traumatic brain hemorrhage, traumatic brain injury, or brain neoplasm. Excluded were patients who died before palliative care consultation or lacked sufficient information. The investigation assessed demographic and clinical characteristics at consultation, along with post-consultation hospital outcomes derived from medical records and interview notes. Results: : In this study involving 38 enrolled patients, the median age was 65, with 42.1% females. The most prevalent diagnosis was nontraumatic brain hemorrhage (47.4%). Reasons for palliative care consultation included psychosocial support (95%), goal-of-care discussions (68%), decision-making support (50%), and communication facilitation (39%). The median time from NS-ICU admission to consultation was 3.5 days (interquartile range, 1–8 days), and all interviews involved family members. Key decision topics encompassed mechanical ventilation (23.7%) and tracheostomy (21.1%). Patient preferences for life-sustaining treatment could be estimated in only 47.4% of cases, often resulting in treatment disagreement. Among the 38 patients, 26 (68.4%) died during admission. Before the consultation, full code status, partial code status, and comfort care alone were reported as 32%, 66%, and 2%, respectively; post-consultation, these figures shifted to 11%, 42%, and 47%, respectively. Conclusion : Palliative care was predominantly sought for psychosocial support and discussions concerning goals of care. Despite challenges in ascertaining patient treatment preferences, palliative care consultations proved invaluable in aiding family members and facilitating treatment decision-making. Our study suggests the potential integration of palliative care within neuro-critical care, contributing to a heightened utilization of comfort care at the end-of-life.

Background: s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018. Methods: Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018. Results: The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%). Conclusions Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.