2.Epidemiology of Gastric Cancer in Korea (1999–2022): Incidence, Survival, and 5-Year Conditional Relative Survival
Ki Bum PARK ; Mee Joo KANG ; Johyun HA ; Eun Hye PARK ; E Hwa YUN ; Hye-Jin KIM ; Kyu-Won JUNG ; Han Hong LEE
Journal of Gastric Cancer 2026;26(1):4-15
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.
3.A Facet-Preserving Modified Transpedicular Approach Using Unilateral Biportal Endoscopy for Thoracic Spinal Pathology
Yong Jin PARK ; Sang Kyu SON ; Young San KO
Journal of Minimally Invasive Spine Surgery and Technique 2026;11(Suppl 1):S214-S218
This study aimed to describe a facet-preserving modified transpedicular unilateral biportal endoscopic (UBE) approach for upwardly migrated thoracic disc herniation that allows safe decompression without spinal cord retraction or postoperative instability. Thoracic disc herniation is rare but often symptomatic, producing myelopathy that typically necessitates surgical intervention. Because of the spinal cord’s close proximity, traditional discectomy approaches carry a high risk of neural injury, and achieving complete disc removal without cord manipulation remains a significant surgical challenge. Although several techniques have been proposed, many are limited by the potential for incomplete decompression or iatrogenic instability. A facet-preserving modified transpedicular UBE approach may overcome these limitations by offering a minimally invasive surgical corridor while maintaining spinal stability. A 76-year-old woman presented with progressive bilateral lower extremity weakness and numbness over 6 months, with rapid deterioration during the past month. Magnetic resonance imaging (MRI) revealed an upwardly migrated thoracic disc herniation at T10–11 compressing the spinal cord. A UBE discectomy using a facet-preserving modified transpedicular approach was performed. The herniated fragment was completely removed without spinal cord retraction. Postoperatively, the patient demonstrated neurological improvement without complications. MRI confirmed complete decompression of the cord, and computed tomography verified preservation of the facet joint. This video article introduces the modified transpedicular UBE approach as a safe and precise minimally invasive technique for thoracic ventral pathologies. By enabling direct ventral decompression while preserving spinal stability, it broadens the scope of endoscopic spine surgery and warrants further clinical validation.
4.Topographic Progression of Geographic Atrophy and Visual Acuity in Nonexudative Age-Related Macular Degeneration
Jun Kyu LEE ; Junwoo LEE ; Jong Beom PARK ; Kiyoung KIM ; Seung-Young YU
Korean Journal of Ophthalmology 2026;40(1):1-11
Purpose:
To investigate long-term topographic progression of the geographic atrophy (GA) area based on location and analyze its correlation with visual acuity in patient with GA secondary to non-neovascular age-related macular degeneration in South Korean patient cohort.
Methods:
Medical records and imaging data of 58 eyes from 34 patients with GA were retrospectively reviewed using fundus autofluorescence (FAF). Regions of interest were defined as concentric ring-shaped zones with diameters of 1, 2, 3, and 4 mm centered on the fovea (zones 0–3), each subdivided into superior, temporal, inferior, and nasal sectors. The foveal center was determined using optical coherence tomography, and sectoral GA areas were measured on FAF with the semiautomated software (RegionFinder ver. 2.6.2.0). Correlations among GA area enlargement, GA growth rate, and changes in best-corrected visual acuity (BCVA) were evaluated.
Results:
The mean GA area enlarged from 4.10 to 16.57 mm2 and mean BCVA decreased from 0.34 to 1.06 logMAR at 5 years of follow-up. The mean overall GA area growth rate was 1.96 mm2/yr. During yearly follow-up from baseline to 5 years, there were significant differences in GA growth rate of zone 3 inferior (p < 0.005). The GA area changes of zone 3 inferior was significantly correlated with BCVA. In the subgroup with BCVA decreased under 1.0 logMAR during follow-up, there was a higher growth rate in zone 2 nasal sector, 2 to 3 years before.
Conclusions
The overall GA growth rate was 1.96 mm2/yr in the 5-year follow-up of our cohort. Changes in the GA growth rate in the nasal perifoveal region (zone 2) may be associated with subsequent clinically meaningful visual decline.
5.Eradication of Aspiculuris tetraptera in various immunodeficient mouse models using ivermectin: a case report
Ji-Hun LEE ; Eun-Seon YOO ; Na-Won KIM ; Han-Bi JEONG ; Ah-Reum KANG ; Sun-Min SEO ; Young-Jun PARK ; Byeong-Cheol KANG ; Yang-Kyu CHOI
Laboratory Animal Research 2026;42(1):82-87
Background:
Despite advancements in laboratory animal facility management, pinworm infections remain a persistent issue in immunodeficient mouse colonies. Rapid diagnosis and treatment are crucial to mitigating potential scientific and economic consequences. Effective control requires both the administration of anthelmintic agents and rigorous environmental decontamination. However, the safety and efficacy of these treatments in genetically modified mouse models remains uncertain.Case presentation Aspiculuris tetraptera infestation was identified in multiple immunodeficient mouse models housed in a laboratory facility. Diagnosis was confirmed through fecal flotation for egg detection and necropsy for adult worm examination in the large intestines. Mice received three subcutaneous ivermectin injections at two-week intervals, coupled with environmental decontamination using ivermectin spray for four consecutive weeks. Following treatment, all colonies tested negative for A. tetraptera without any mortality.
Conclusions
A combination of subcutaneous ivermectin injection and environmental spray application effectively eradicated A. tetraptera infestation in immunodeficient mouse colonies. The treatment protocol led to the complete elimination of eggs and adult worms, offering a practical strategy for managing pinworm infections in genetically modified mouse models. Limitations include the small sample size, and the lack of a comprehensive evaluation of physiological and metabolic safety in immunodeficient mice. Further validation will be required to confirm the broader applicability of this approach.
6.WWP2 ubiquitin ligase promotes colorectal cancer progression by targeting p53 for degradation:an experimental study
Seung-Jun LEE ; Han-Gil KIM ; Young-Tae JU ; Young-Sool HAH ; Jeongyun HWANG ; Jihun CHOI ; Jin-Kyu CHO ; Chi-Young JEONG ; Young-Joon LEE ; Ji-Ho PARK ; Ju-Yeon KIM ; Jae-Myung KIM ; Seung-Jin KWAG
Annals of Surgical Treatment and Research 2026;110(5):331-346
Purpose:
Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, necessitating the identification of novel therapeutic targets. The E3 ubiquitin ligase WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) has been implicated in various cancers, yet its specific role and underlying molecular mechanisms in CRC are poorly understood. This study aimed to investigate the functional role of WWP2 in CRC progression and to elucidate its regulatory mechanisms.
Methods:
WWP2 expression was evaluated in CRC patient tissues and cell lines using immunohistochemistry, quantitative real-time polymerase chain reaction, and western blotting. The biological functions of WWP2 were assessed using in vitro assays for cell proliferation, migration, and invasion following adenovirus-mediated overexpression. The molecular mechanism was investigated by analyzing the protein expression levels of p53 and its downstream target, p21, via western blot. An in vivo xenograft mouse model was used to confirm the oncogenic role of WWP2.
Results:
WWP2 expression was significantly upregulated in CRC tissues. Overexpression of WWP2 promoted CRC cell proliferation, migration, and invasion. Mechanistically, increased WWP2 expression led to a marked reduction in the protein levels of the tumor suppressor p53. Consequently, the expression of the p53 downstream target, the cell cycle inhibitor p21, was also suppressed. In the xenograft model, WWP2 overexpression significantly enhanced tumor growth.
Conclusion
Our findings demonstrate that WWP2 functions as an oncogene in CRC. It promotes cancer progression by destabilizing the tumor suppressor p53 and downregulating p21. This study highlights the WWP2-p53-p21 axis as a potential novel therapeutic target for CRC.
7.Primary Intradural Extramedullary Ewing Sarcoma of the Thoracic Spine With Leptomeningeal and Brain Metastases:A Case Report and Literature Review
Achmad Harun MUCHSIN ; Woochan PARK ; Yu Jung KIM ; Koung Jin SUH ; Jeong Min SEO ; Kyu Sang LEE ; Keun-Yong EOM ; Seung-Jae HYUN
Brain Tumor Research and Treatment 2026;14(2):102-108
A 43-year-old woman presented with bilateral lower extremity weakness due to an intradural extramedullary spinal cord tumor. Surgery revealed Ewing sarcoma, a rare presentation known as primary intradural extramedullary Ewing sarcoma (PIEES). Despite initial treatment with radiation and chemotherapy, tumor recurrence occurred after 17 months. Further interventions included additional surgery, radiation, and chemotherapy. The disease progressed to leptomeningeal metastases along the spinal cord, prompting various treatments including targeted spinal radiation and systemic therapies. Brain metastases subsequently developed, necessitating whole-brain radiation and intrathecal chemotherapy. This case highlights the aggressive nature of PIEES, its potential for widespread leptomeningeal metastasis, and the challenges in its management, underscoring the need for multidisciplinary approaches in treating this rare and aggressive malignancy.
8.Prediction of Cancer Incidence and Mortality in Korea, 2026
Kyu-Won JUNG ; Mee Joo KANG ; Eun Hye PARK ; E Hwa YUN ; Hye-Jin KIM ; Jeong-Eun KIM ; Kui Sun CHOI ; Han-Kwang YANG
Cancer Research and Treatment 2026;58(2):368-375
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.
9.Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2023
Eun Hye PARK ; Kyu-Won JUNG ; Seo Hyun CHOI ; Nam Ju PARK ; Mee Joo KANG ; E Hwa YUN ; Hye-Jin KIM ; Jeong-Eun KIM ; Kui Son CHOI ; Han-Kwang YANG ;
Cancer Research and Treatment 2026;58(2):349-367
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.
10.Comparison of Surveillance with Low-Dose and Contrast-Enhanced Chest Computed Tomography in Patients Disease-Free for 2 Years after Curative Resection for Lung Cancer
Bubse NA ; Ji Hyeon PARK ; Kwon Joong NA ; Samina PARK ; Chang Hyun KANG ; Young Tae KIM ; In Kyu PARK
Cancer Research and Treatment 2026;58(2):454-464
Purpose:
Low-dose chest computed tomography (LDCT) is recommended for surveillance 2–3 years after curative resection of non-small cell lung cancer (NSCLC); however, supporting clinical evidence is limited. This study compared LDCT with contrast-enhanced chest computed tomography (CECT) in terms of recurrence detection and overall survival (OS) in patients 2 years after curative resection of NSCLC.
Materials and Methods:
Among patients who underwent curative resection for NSCLC between January 2011 and December 2017 and survived for 2 years without recurrence, 2,083 patients were included. Comparisons between the LDCT and CECT groups were performed in both the entire cohort and propensity score-matched cohort. The primary outcome was the difference in overall survival. Secondary outcomes included time-to-recurrence, recurrence-free survival, and post-recurrence survival in each group.
Results:
In the propensity score-matched population, the 5-year OS (96.0% for LDCT, 98.0% for CECT, p=0.097) and recurrence-free survival (RFS) (95.4% for LDCT, 96.0% for CECT, p=0.761) did not differ. The OS and RFS did not differ in subgroup analyses stratified by pathologic stage and histologic type. In the competing risk analysis, the overall 5-year cumulative incidence of recurrence did not differ between the two groups (4.56% for LDCT, 3.93% for CECT, p=0.765). When stratified by pathologic stage and histologic type, there was no significant difference in the cumulative incidence of recurrence. The distribution of recurrence sites did not differ between groups.
Conclusion
Similar OS and RFS were observed in LDCT and CECT surveillance in patients who achieved a 2-year disease-free status after curative resection for NSCLC.

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