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: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

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.

Objectives: To propose age group classification criteria for efficient tooth loss management by ana-lyzing the distribution of tooth loss in Korean adults by age group and causes of tooth loss. In addi-tion, to determine the efficacy of a Significant Tooth Loss index. Methods: The study included 13,199 adults who participated in the seventh Korea National Health and Nutrition Examination Survey (2016-2018). The mean number of missing teeth was compared by classifying the ages into 10- and 5-year intervals. Based on this analysis, the distribution of missing teeth was determined by classifying the age groups into 15-year intervals. Subsequently, the causes of tooth loss by age group at 15-year intervals and the efficacy of the Significant Tooth Loss Index were determined. Results: Classification at 5-year age intervals was more appropriate for analyzing changes in the distribution of missing teeth than classification at 10-year age intervals. However, establishing a public oral health program for the management of tooth loss on a 5-year or 10-year basis is im-practical. Therefore, a classification method with 15-year age intervals was proposed, in which the groups were young (19-34 years), middle-aged (35-49 years), older adult (50-64 years), and elderly (65 years or older). Although the criteria for the Significant Tooth Loss Index were appropri-ate for the young, older adults, and elderly groups, modifications were required for the middle-aged group. Conclusions Age-based oral health programs for adults should be promoted to prevent tooth loss by classifying adults into different age groups based on their clinical characteristics.

Background: To investigate the clinicopathologic pattern of prostate cancer (PCa) in elderly patients compared with their younger counterparts with a prostate-specific antigen (PSA) level below the low-risk threshold (< 10 ng/mL), which is often a deciding factor for biopsy. Methods: A nationwide database of PCa at the time of biopsy from 2010 to 2020 was constructed from 39 hospitals. Patients were categorized into age groups of < 64 years, 65–69 years, 70–74 years, and ≥ 75 years considering guidelines that recommend PSA testing only for those aged 55–69 years during the study period, the average age of Korean PCa registrants of 70.3 years (2010–2020), and the average life expectancy of Korean males of 80.3 years (2020). Results: The mean ± standard deviation age was 70.3 ± 8.2 years, which was normally distributed (kurtosis = 0.095). Among 14,548 subjects, 54.1%, 39.5%, and 6.4% of them had high-risk disease, intermediate-risk disease, and low-risk disease, respectively. Based on three risk parameters, a marked increase in high-risk cancer was observed in the oldest age group (linear combination, P < 0.001). The same pattern was observed among patients with low-risk disease (PSA < 10 ng/mL), who were divided into PSA tiers as follows: 4–5 ng/mL (P < 0.001), 5–6 ng/mL (P < 0.001), 6–7 ng/mL (P < 0.001), 7–8 ng/mL (P < 0.001), 8–9 ng/mL (P = 0.009), and 9–10 ng/mL (P < 0.001). In all PSA tiers between 4 and 10 ng/mL, multivariate analysis demonstrated a significantly higher prevalence of high-risk cancer in the oldest age group than in the youngest age group. In the lowest tier (4–5 ng/mL), 35.2% of those aged over 75 years had high-risk PCa. Conclusion The older the patient, the more aggressive the PCa. Moreover, there was an increase in high-risk PCa in older males compared with younger males even with a PSA level below the low-risk threshold of 10 ng/mL, suggesting the need to strengthen cancer screening policies in the older population.

The applicability of the Phoenix criteria and Phoenix Sepsis Score in higher-resource pediatric intensive care units (PICUs) outside the United States requires further validation. A retrospective cohort study analyzed electronic health records of 1,304 PICU admissions under 18 years old with suspected infection between February 2017 and December 2023. The score was calculated using two methods: 24-hour assessment, based on worst sub-scores within 24 hours of admission, and prompt assessment, using values closest to admission within 6 hours before or after. Based on the 24-hour assessment, in-hospital mortality was 8.3% for sepsis and 10.3% for septic shock. The score demonstrated an area under the precision-recall curve of 0.42 (95% confidence interval, 0.31–0.55) for in-hospital mortality. Results were consistent across both assessment methods. The Phoenix criteria and the Phoenix Sepsis Score are reliable predictors of mortality outcomes. Further investigation in diverse clinical settings is warranted.

Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.

Diagnosing amyotrophic lateral sclerosis (ALS) is challenging and requires distinguishing it from conditions like distal hereditary motor neuropathy type 5 (dHMN-V). A 21-year-old female initially diagnosed with ALS showed progressive upper limb weakness extending to the lower limbs. Trio exome sequencing revealed a de novo pathogenic Berardinelli-Seip congenital lipodystrophy 2 variant (c.263A>G, p.Asn88Ser), confirming dHMN-V. Minipolymyoclonus of small amplitudes in bilateral wrists and ankles was an atypical presentation. This case underscores the importance of considering dHMN-V as a differential diagnosis in ALS-like distal upper extremity weakness.