Purpose: This study evaluated long-term trends in gastric cancer epidemiology and survival with a focus on conditional relative survival (CRS). Materials and Methods: Using the Korea Central Cancer Registry, we analyzed 665,184 patients who were newly diagnosed with gastric cancer between 1999 and 2022.The study period was divided into four intervals: Period I (1999–2005), Period II (2006–2011), Period III (2012–2017), and Period IV (2018–2022). Temporal trends in the incidence and mortality were assessed using crude and age-standardized rates. Relative survival was estimated using the Ederer II method, and the 5-year CRS was calculated according to the survival duration after diagnosis. Results: The incidence of gastric cancer increased until 2011 and subsequently declined, with a marked decrease observed in 2020. Individuals aged ≥70 years consistently had the highest incidence rates. Mortality rates showed a sustained decline throughout the study period. The overall 5-year relative survival improved from 69.8% in Period II to 78.4% in Period IV. The 5-year CRS increased from 86.1% at 1 year after diagnosis to 96.3% at 5 years.Patients with localized stage maintained a 5-year CRS above 95% at 1 year after diagnosis, whereas those with regional and distant stages showed 5-year CRS that consistently remained below 95%. Conclusions The incidence and mortality rates of gastric cancer in Korea have declined over the past two decades, accompanied by improved survival outcomes. The CRS analysis suggests that long-term follow-up is warranted, with the optimal duration varying according to patient characteristics.

Alzheimer’s disease (AD) is characterized by progressive cognitive deterioration and significant depression. However, the mechanisms linking depression to AD pathology remain unclear. Here, we investigated whether Notch2 signaling mediates depressionlike behaviors in presenilin-2 (PS2) N141I mutant mice, an early-onset AD model. PS2 wild-type (WT) and mutant (MT) mice aged 12-15 months were subjected to unpredictable chronic mild stress (UCMS) for 4 weeks, followed by sucrose preference, tail-hanging, and forced swimming tests. Behavioral assessments showed that UCMS exacerbated anhedonia and immobility only in PS2 MT mice. Molecular analysis revealed concomitant increases in plasma corticosterone, hippocampal γ-secretase activity, and Notch2 expression, and elevated total and phosphorylated glucocorticoid receptor levels in PS2 MT-UCMS mice. Gene expression profiling of human hippocampal datasets confirmed upregulation of NOTCH2 in Alzheimer’s disease and depression.Pharmacological inhibition of γ-secretase and Notch signaling with DAPT normalizes depressive behavior, reduces corticosterone release, attenuates GR phosphorylation, and inhibits Notch2 signaling in PS2 MT mice. These findings identify Notch2 as a pivotal mediator linking chronic stress to molecular changes associated with depression and AD, and suggest that targeting Notch2 signaling may provide therapeutic benefits for comorbid mood and neurodegenerative disorders.

Purpose: This study aimed to project cancer incidence and mortality for 2026 to estimate Korea’s current cancer burden. Materials and Methods: Cancer incidence data from 1999 to 2023 were obtained from the Korea National Cancer Incidence Database, while cancer mortality data from 1993 to 2024 were acquired from the Ministry of Data and Statistics. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against their respective years and then by the projected age-specific rates by the anticipated age-specific population for 2026. A joinpoint regression model was applied to identify significant changes in trends, using only the most recent trend data for predictions. Results: A total of 308,876 new cancer cases and 86,317 cancer deaths are expected in Korea in 2026. The most commonly diagnosed cancer is projected to be thyroid cancer, followed by the colorectal, lung, breast, prostate and stomach cancers. These six cancers are expected to account for 63.5% of all newly diagnosed cancers. Lung cancer is expected to be the leading cause of cancer-related deaths, followed by liver, colorectal, pancreatic, gallbladder, and stomach cancers, together comprising 65.9% of all cancer deaths. Conclusion Korea’s cancer burden continues to shift toward malignancies prevalent in older populations. The sustained increase in prostate cancer among men and the rising mortality impact of pancreatic cancer reflect structural changes in the national cancer profile amid rapid population aging.

Purpose: The current study provides national cancer statistics and their secular trends in Korea, including incidence, mortality, survival, and prevalence in 2023, with international comparisons. Materials and Methods: Cancer incidence, survival, and prevalence rates were calculated using the Korea National Cancer Incidence Database (1999-2023), with survival follow-up until December 31, 2024. Mortality data were obtained from the Ministry of Data and Statistics, while international comparisons were based on GLOBOCAN data. Results: In 2023, 288,613 newly diagnosed cancer cases (age-standardized rate [ASR], 288.6 per 100,000) and 85,271 deaths from cancer (ASR, 64.3 per 100,000) were reported. Among the incident cases, 145,452 (50.4%) were aged 65 years or older. Prostate cancer became the most common cancer among men for the first time. The proportion of localized-stage cancers increased from 45.6% in 2005 to 51.8% in 2023. Korea had the lowest cancer mortality among countries with similar incidence rates and the lowest mortality-to-incidence ratios for stomach, colorectal, and breast cancer. The 5-year relative survival rate (2019-2023) was 73.7% overall and 92.7% for localized-stage cancers. Over 2.73 million prevalent cases were identified in 2023, representing 5.3% of the Korean population. Conclusion These findings indicate that Korea’s cancer control efforts have contributed to early detection and improved survival outcomes. As Korea enters a super-aged society in 2025, cancer burden will continue to increase, requiring sustained and adaptive cancer control strategies.

Background: Intradialytic hypotension (IDH) is a critical complication related to worse outcomes in patients undergoing maintenance hemodialysis. Herein, we addressed the impact of IDH on mortality and other outcomes in patients with severe acute kidney injury (AKI) requiring intermittent hemodialysis. Methods: We retrospectively reviewed 1,009 patients who underwent intermittent hemodialysis due to severe AKI. IDH was defined as either dialysis discontinuation due to hemodynamic instability or a decrease in systolic blood pressure (BP) of ≥30 mmHg, with or without a nadir systolic BP of <90 mmHg during the first session. The primary outcome was all-cause mortality, and transfer to the intensive care unit (ICU) due to unstable status was additionally analyzed. Hazard ratios (HRs) of outcomes were calculated using a Cox regression model after adjusting for multiple variables. Risk factors for IDH were evaluated using a logistic regression model. Results: IDH occurred in 449 patients (44.5%) during the first hemodialysis session. Patients with IDH had a higher mortality rate than those without IDH (40% vs. 23%; HR, 1.30; 95% confidence interval [CI], 1.02–1.65). The rate of ICU transfer was higher in patients experiencing IDH than in those without IDH (17% vs. 11%; HR, 1.43; 95% CI, 1.02–2.02). Factors such as old age, high BP and pulse rate, active malignancy, cirrhosis, and hypoalbuminemia were associated with an increased risk of IDH episodes. Conclusion The occurrence of IDH is associated with worse outcomes in patients with AKI requiring intermittent hemodialysis. Therefore, careful monitoring and early intervention of IDH may be necessary in this patient subset.

Background and Objectives: The clinical significance of incidental pulmonary nodules detected during thyroid cancer evaluation remains unclear. This study aimed to investigate how such findings affect surgical decisionmaking and whether management differs by physician characteristics. Materials and Methods: A web-based survey was distributed to 722 active members of the Korean Thyroid Association in March 2025. Eligible participants included board-certified endocrinologists, endocrine surgeons, and otolaryngologists actively treating thyroid cancer. The questionnaire included clinical scenarios featuring incidental lung nodules found during thyroid cancer work-up, with respondents asked to choose preferred surgical extent (thyroid lobectomy vs. total thyroidectomy) and management approaches. Results: Out of 72 physicians who completed the survey, half (n=36, 50.0%) of the respondents answered that the presence of incidental lung nodules could influence their decision on thyroidectomy extent. Among those influenced by lung nodules, 86.1% recommended total thyroidectomy in patients with high- or intermediate-risk thyroid cancer, while 11.1% would do so for all thyroid cancer patients.Endocrinologists, compared to surgeons, were more likely to choose total thyroidectomy in patients with preoperative incidental lung nodules (78.3% vs. 36.7%, p=0.001). Conclusion Incidental lung nodules may influence surgical planning in clinicians due to the risk of micrometastasis from thyroid cancer. Endocrinologists tend to favor a more extensive surgical approach compared to surgeons, reflecting greater concern for potential metastatic disease. These findings underscore the need for multidisciplinary consensus guidelines for the management of incidental pulmonary nodules in thyroid cancer patients.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

This study explores the development, roles, and key initiatives of the Regional Environmental Health Centers in Korea, detailing their evolution through four distinct phases and their impact on environmental health policy and local governance. It chronicles the establishment and transformation of these centers from their inception in May 2007, through four developmental stages. Originally named Environmental Disease Research Centers, they were subsequently renamed Environmental Health Centers following legislative changes. The analysis includes the expansion in the number of centers, the transfer of responsibilities to local governments, and the launch of significant projects such as the Korean Children’s Environmental Health Study (Ko-CHENS ). During the initial phase (May 2007–February 2009), the 10 centers concentrated on research-driven activities, shifting from a media-centered to a receptor-centered approach. In the second phase, prompted by the enactment of the Environmental Health Act, six additional centers were established, broadening their scope to address national environmental health issues. The third phase introduced Ko-CHENS, a 20-year national cohort project designed to influence environmental health policy by integrating research findings into policy frameworks. The fourth phase marked a decentralization of authority, empowering local governments and redefining the centers' roles to focus on regional environmental health challenges. The Regional Environmental Health Centers have significantly evolved and now play a crucial role in addressing local environmental health issues and supporting local government policies. Their capacity to adapt and respond to region-specific challenges is essential for the effective implementation of environmental health policies, reflecting geographical, socioeconomic, and demographic differences.

To investigate the relationship between depression and AD, water avoidance stress (WAS) was induced for 10 days in both Tg2576 mice and wild-type (WT) mice. After WAS, memory function and depressive-like behavior were investigated in Tg2576 mice. Tg2576 WAS mice exhibited more depressive-like behaviors than WT WAS and Tg2576 control (CON) mice. Strikingly, Tg2576 CON mice showed more depressive-like behaviors than WT mice. Moreover, corticosterone and phospho-glucocorticoid receptor (p-GR) levels were also higher in Tg2576 WAS mice in comparison to Tg2576 CON mice. Spinster homologue 2 (SPNS2) is a member of non-ATP-dependent transporter. The role of SPNS2 was widely known as a sphingosine-1-phosphate (S1P) transporter, which export intracellular S1P from cells. Using GEO database to analyze SPNS2 gene expression changes in patients with AD and depression, we show that SPNS2 gene expression correlates with AD and depression. Interestingly, Tg2576 WAS mice displayed significantly increased levels of SPNS2 w1hen compared to Tg2576 CON counterparts. SPNS2 levels were also higher in Tg2576 CON mice in comparison with WT CON mice. Remarkably, we found a decrease in S1P brain levels and an increase in S1P serum levels of Tg2576 WAS mice in comparison with Tg2576 CON mice. Accordingly, WAS induced group further decreased S1P levels in the brains. However, the level in the serum further increased in comparison with non-induced group. Therefore, these results suggest that AD and depression could be associated, and that Tg2576 transgenic mice are more susceptible to stress-induced depression through the release of S1P by SPNS2 up-regulation.

Purpose: This study aimed to project cancer incidence and mortality for 2025 to estimate Korea’s current cancer burden. Materials and Methods: Cancer incidence data from 1999 to 2022 were obtained from the Korea National Cancer Incidence Database, while cancer mortality data from 1993 to 2023 were acquired from Statistics Korea. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against their respective years and then by multiplying the projected age-specific rates by the anticipated age-specific population for 2025. A joinpoint regression model was applied to identify significant changes in trends, using only the most recent trend data for predictions. Results: A total of 304,754 new cancer cases and 84,019 cancer deaths are expected in Korea in 2025. The most commonly diagnosed cancer is projected to be thyroid cancer, followed by the colorectal, lung, breast, prostate and stomach cancers. These six cancers are expected to account for 63.8% of the total cancer burden. Lung cancer is expected to be the leading cause of cancer-related deaths, followed by liver, colorectal, pancreatic, stomach, and gallbladder cancers, together comprising 66.6% of total cancer deaths. Conclusion The increasing incidence of female breast cancer and the rise in prostate and pancreatic cancers are expected to continue. As aging accelerates, cancer commonly found in older adults are projected to rise significantly.