Purpose: This study analyzed the pathological complete response (pCR) rates, long-term outcomes, and biological features of human epidermal growth factor receptor 2 (HER2)-zero, HER2-low, and HER2-positive breast cancer patients undergoing neoadjuvant treatment. Methods: This single-center study included 1,667 patients who underwent neoadjuvant chemotherapy from 2008 to 2014. Patients were categorized by HER2 status, and their clinicopathological characteristics, chemotherapy responses, and recurrence-free survival (RFS) rates were analyzed. Results: Patients with HER2-low tumors were more likely to be older (p = 0.081), have a lower histological grade (p < 0.001), and have hormone receptor (HorR)-positive tumors (p < 0.001). The HER2-positive group exhibited the highest pCR rate (23.3%), followed by the HER2-zero (15.5%) and HER2-low (10.9%) groups. However, the pCR rate did not differ between HER2-low and HER2-zero tumors in the HorR-positive or HorR-negative subgroups.The 5-year RFS rates increased in the following order: HER2-low, HER2-positive, and HER2-zero (80.0%, 77.5%, and 74.5%, respectively) (log-rank test p = 0.017). A significant survival difference between patients with HER2-low and HER2-zero tumors was only identified in HorR-negative tumors (5-year RFS for HER2-low, 74.5% vs. HER2-zero, 66.0%; log-rank test p-value = 0.04). Multivariate survival analysis revealed that achieving a pCR was the most significant factor associated with improved survival (hazard ratio [HR], 4.279; p < 0.001).Compared with HER2-zero, the HRs for HER2-low and HER2-positive tumors were 0.787 (p = 0.042) and 0.728 (p = 0.005), respectively. After excluding patients who received HER2-targeted therapy, patients with HER2-low tumors exhibited better RFS than those with HER2-zero (HR 0.784, p = 0.04), whereas those with HER2-positive tumors exhibited no significant difference compared with those with HER2-low tumors (HR, 0.975; p = 0.953). Conclusion Patients with HER2-low tumors had no significant difference in pCR rate compared to HER2-zero but showed better survival, especially in HorR-negative tumors.Further investigation into biological differences is warranted.

Background: The 5th edition of WHO classification (WHO5) renamed pituitary adenoma as pituitary neuroendocrine tumor (PitNET), aligning with NET nomenclature from other sites.This study investigated the clinicopathological characteristics of surgically resected PitNET based on the WHO5 classification. Methods: A retrospective analysis was conducted on 210 cases of surgically resected and pathologically confirmed PitNET treated at Seoul National University Hospital from 2021 to 2023. The tumors were graded using the French five-tiered grading system proposed by Trouillas et al. Detailed information on grade 3 metastatic PitNET cases is provided. Results: The cohort’s median age was 53 years (age range: 8–84 years), with a male-to-female ratio of 1:1.1. Mean tumor size was 2.5 cm (range: 0.1–6.5 cm). Macroadenomas predominated (91.9%), followed by microadenoma (6.7%), and giant tumors (1.4%), with 56.2% extending suprasellarly. SF1-lineage PitNET was most prevalent (49.5%), followed by PIT1-lineage (23.3%) and TPIT-lineage (17.1%). Null cell tumors (5.7%) and unclassified plurihormonal PitNET (4.3%) were rare. PIT1-lineage PitNET comprised somatotrophs (47.0%), mature plurihormonal PIT1 lineage tumors (18.4%), thyrotrophs (16.3%), immature PIT1-lineage tumors (16.3%), and acidophilic stem cell tumors (n=1), however, there was no lactotroph PitNET. Among SF1-lineage tumors, serologically non-functional tumors predominated (79%), while, immunohistochemically, 71.2% were gonadotrophin (FSH/LH)-positive.Tumor grades by the French five-tiered classification system were distributed as follows:grade 1a (58.1%), 1b (17.6%), 2a (16.2%), 2b (7.1%), and 3 (1.0%). Two cases of metastatic corticotroph PitNET were observed: The first case, a 50-year-old female had liver metastasis and experienced tumor recurrence 7 years after his initial diagnosis of PitNET, ultimately dying 9.5 years later. The primary tumor appeared bland, but the metastatic tumor exhibited a high mitotic rate and a Ki-67 index was 48%. The second case involved a 44-year-old man with metastases to the paranasal sinus, liver, and bone. Despite showing initial bland histopathology and a low proliferation index, this tumor displayed aggressive behavior.The patient had a recurrence 1.5 years after diagnosis, with additional metastases emerging 3 years later. He survived for 8.0 years and is currently disease-free following surgery, chemotherapy, and radiotherapy. Conclusion This comprehensive analysis of surgically resected PitNETs using the new WHO5 classification provides valuable insights into the distribution of the subtypes in the surgical cohort. Key findings were the predominant gonadotroph PitNET, the absence of lactotroph PitNET, and the rarity of null cell tumors in surgical cases. The lack of lactotrophs was mainly due to medical treatment. This study highlights the discrepancy between serological and immunohistochemical findings of SF1-lineage PitNETs. While metastatic PitNET cases showed poor prognosis, the predictive value of the French grading system for PitNET requires further validation through extended follow-up.

Background/Aims: Fexuprazan, a novel potassium-competitive acid blocker, was developed for treating acid-related disorders. Pharmacokinetic and pharmacodynamic properties of fexuprazan, unlike those of proton pump inhibitors, are independent of food effect. This study aims to evaluate differences in efficacy and safety of fexuprazan in patients with erosive esophagitis (EE) according to the timing of dosing. Methods: In this multicenter, open-label noninferiority study, patients who had typical reflux symptoms with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg daily 30 minutes before or after meal. Treatment was completed after 2 weeks or 4 weeks when healing was endoscopically confirmed. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy up to week 4. Safety endpoints included treatment-emergent adverse events (TEAEs). Results: In the prior-to-meal group (n = 89) and after-meal group (n = 86), 4-week EE healing rates were 98.77% and 100.00% (difference, 0.01%; 95% CI, –0.01% to 0.04%) and 2-week EE healing rates were 95.77% and 97.14% (difference, 0.01%; 95% CI, –0.05% to 0.07%), respectively. TEAEs were 9.78% and 8.70% in the prior-to-meal group and the after-meal group, respectively. Conclusions Non-inferiority analysis revealed that taking fexuprazan after meal was non-inferior to taking fexuprazan before meals in patients with EE. The frequency of adverse events was similar between the 2 study groups. The drug is safe and effective for healing EE regardless of the timing of dosing.

Objectives: This study examined the potential of a new analytical framework for the Korea Community Health Survey (KCHS) with classification criteria for the sub-national governmental level, the degree of urbanization including an urban-rural multimodal category, and population size as a more effective tool to address local health problems and deduce practical implications. Methods: Retrospective survey data from 2023 KCHS were obtained. Frequency analyses were performed for self-rated good health status, current smoking status, and unmet medical needs as proxies for health status, as well as health behavior and healthcare utilization, utilizing individual weights to represent national community residents. Results: We established a new classification of local governments into 7 types to facilitate regional comparisons. These local government types are presumably composed of populations showing statistically significant differences in demographic characteristics. There were evident differences in health status, health behavior, and healthcare utilization in comparisons of groups categorized by local government types. Conclusions This study suggests that regional disparities can be analyzed using a new typology of local governments. This practically effective approach could be used in decision-making for community-centered health projects in terms of community health planning. Future research should conduct analyses of KCHS data that use these 7 local government types to comprehensively reflect regional characteristics.

Objectives: Lonely death is defined as “a person living in a state of social isolation, disconnected from family, relatives, and others, who dies from suicide, illness, or other causes”. This study investigated the characteristics of individuals who die alone in Korea. Methods: We constructed a database of lonely death cases by linking data from the Korea Crime Scene Investigation Unit of the Korea National Police Agency with National Health Insurance Service (NHIS) records. A descriptive analysis was performed to evaluate the demographics, underlying diseases, and healthcare utilization patterns among lonely death cases. Results: Among the 3122 individuals identified as lonely death cases, 2621 (84.0%) were male and 501 (16.0%) were female. The most common age group was 50-59 years (n=930, 29.8%). The NHIS covered 2161 individuals (69.2%), whereas 961 individuals (30.8%) were enrolled in Medical Aid (MA). The highest number of lonely deaths occurred in Seoul areas, with 1468 cases (47.0%). Mood disorders were diagnosed in 1020 individuals (32.7%), and various alcohol-related diseases, including alcoholic liver disease, were also observed. Outpatient visits increased leading up to death but declined in the final 3 months, while hospitalizations decreased and emergency room visits slightly increased. Conclusions Most lonely death cases involved male in their 50s, with a disproportionately high number of MA beneficiaries compared to the general population. Many of these individuals also experienced mental health issues or alcohol-related disorders. Preventing social isolation and strengthening social safety nets are critical to reducing the occurrence of lonely deaths.

Background and Objectives: Pediatric chronic rhinosinusitis (CRS) significantly affects children’s quality of life and learning abilities. This study aimed to evaluate the postoperative outcomes in pediatric patients who underwent functional endoscopic sinus surgery (FESS) for CRS. Methods: A retrospective review was conducted on pediatric patients who underwent FESS for CRS at 11 university hospitals. The inclusion criteria were patients under 20 years old with bilateral disease who were operated on between January 2005 and December 2021. The data collected included demographics, clinical history, blood tests, preoperative computed tomography, and preoperative and postoperative symptom control. The Kruskal-Wallis and Fisher exact tests were used to compare the quantitative and qualitative data, respectively. Results: In total, 213 patients were enrolled. The mean age was 13.4±3.0 years, and 145 (68.1%) were male. One hundred sixty-four patients (77.0%) had nasal polyps and 33 patients (15.5%) underwent revision FESS. The preoperative symptoms, in order of prevalence, included nasal obstruction (87.8%), rhinorrhea (71.8%), a sense of postnasal drip (58.2%), hyposmia (44.6%), cough (24.4%), and facial fullness (18.3%). These symptoms were significantly alleviated for up to 3 years after surgery (p<0.001). At the time of the last follow-up, 121 patients (56.8%) were controlled, 80 (37.6%) were partly controlled, and 12 (5.6%) were uncontrolled. Patients in the uncontrolled group had higher Lund-Mackay scores, longer follow-up durations, and more instances of revision surgery compared to those in the controlled and partly controlled groups. When age was categorized into three groups, those aged 16 years or older tended to have lower Lund-Mackay scores and better control. Conclusion FESS significantly improves both the postoperative symptoms and the long-term quality of life in pediatric CRS patients. Better symptom control is associated with older age and a lower disease burden.

Background and Objectives: The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients. Methods: Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage. Results: The median ages of the recipients and donors were 56.0 and 43.0 years, respectively.Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival. Conclusions In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.

Background/Aims: Fexuprazan, a novel potassium-competitive acid blocker, was developed for treating acid-related disorders. Pharmacokinetic and pharmacodynamic properties of fexuprazan, unlike those of proton pump inhibitors, are independent of food effect. This study aims to evaluate differences in efficacy and safety of fexuprazan in patients with erosive esophagitis (EE) according to the timing of dosing. Methods: In this multicenter, open-label noninferiority study, patients who had typical reflux symptoms with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg daily 30 minutes before or after meal. Treatment was completed after 2 weeks or 4 weeks when healing was endoscopically confirmed. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy up to week 4. Safety endpoints included treatment-emergent adverse events (TEAEs). Results: In the prior-to-meal group (n = 89) and after-meal group (n = 86), 4-week EE healing rates were 98.77% and 100.00% (difference, 0.01%; 95% CI, –0.01% to 0.04%) and 2-week EE healing rates were 95.77% and 97.14% (difference, 0.01%; 95% CI, –0.05% to 0.07%), respectively. TEAEs were 9.78% and 8.70% in the prior-to-meal group and the after-meal group, respectively. Conclusions Non-inferiority analysis revealed that taking fexuprazan after meal was non-inferior to taking fexuprazan before meals in patients with EE. The frequency of adverse events was similar between the 2 study groups. The drug is safe and effective for healing EE regardless of the timing of dosing.

Objectives: This study examined the potential of a new analytical framework for the Korea Community Health Survey (KCHS) with classification criteria for the sub-national governmental level, the degree of urbanization including an urban-rural multimodal category, and population size as a more effective tool to address local health problems and deduce practical implications. Methods: Retrospective survey data from 2023 KCHS were obtained. Frequency analyses were performed for self-rated good health status, current smoking status, and unmet medical needs as proxies for health status, as well as health behavior and healthcare utilization, utilizing individual weights to represent national community residents. Results: We established a new classification of local governments into 7 types to facilitate regional comparisons. These local government types are presumably composed of populations showing statistically significant differences in demographic characteristics. There were evident differences in health status, health behavior, and healthcare utilization in comparisons of groups categorized by local government types. Conclusions This study suggests that regional disparities can be analyzed using a new typology of local governments. This practically effective approach could be used in decision-making for community-centered health projects in terms of community health planning. Future research should conduct analyses of KCHS data that use these 7 local government types to comprehensively reflect regional characteristics.