1.Comparison of Fexuprazan and Esomeprazole for the Control of Nocturnal Gastroesophageal Reflux Symptoms: A Randomized, Crossover Study
Dong Jun OH ; Dong Hwan PARK ; Jiyun JUNG ; Yun Jeong LIM
Journal of Neurogastroenterology and Motility 2026;32(1):52-60
Background/Aims:
Nocturnal acid reflux disrupts sleep and impairs quality of life. Proton pump inhibitors provide insufficient suppression of nocturnal acid secretion, whereas fexuprazan offers prolonged acid suppression. We compared the efficacy of fexuprazan and esomeprazole in controlling nocturnal reflux.
Methods:
In a randomized and crossover study, patients received fexuprazan or esomeprazole daily for 4 weeks, followed by a washout and crossover to the alternate medication for another 4 weeks, with a final washout completing the sequence. Severity (scores 0-10), frequency, sleep disturbance, and medication preferences were evaluated.
Results:
Thirty-nine patients were enrolled and randomized to receive either fexuprazan (n = 20) or esomeprazole (n = 19) first. After the first treatment, fexuprazan reduced severity from 7.5 ± 1.7 to 1.4 ± 1.7 (81.3% decrease), versus 7.8 ± 1.5 to 2.8 ± 1.9 (64.1% decrease) with esomeprazole (P = 0.012). In patients with severe symptoms (scores ≥ 7), fexuprazan led to significantly greater improvement than esomeprazole (P = 0.008). Following the first washout, the second crossover treatment resulted in greater improvement in symptom severity with fexuprazan (P = 0.001). During the second washout, nocturnal symptoms severity and frequencies were better controlled with fexuprazan than with esomeprazole (P = 0.005 and 0.019). Patients who switched from esomeprazole to fexuprazan preferred fexuprazan (P = 0.018).
Conclusions
Fexuprazan was more effective than esomeprazole in controlling nocturnal reflux symptom, particularly in patients with severe symptoms. Fexuprazan may offer a therapeutic advantage for patients with severe and persistent nocturnal reflux despite proton pump inhibitor therapy.
2.Prevalence of HER2-ultralow breast cancer in South Korea: a multicenter study by reassessment of HER2-zero cases
Min Chong KIM ; Eun Yoon CHO ; Hee Jin LEE ; Ji Shin LEE ; Jee Yeon KIM ; Wan Seop KIM ; Chungyeul KIM ; Sun-Young JUN ; Hye Jeong CHOI ; So Mang LEE ; Ahrong KIM ; Ji-Young KIM ; Jeong Yun SHIM ; Gyungyub GONG ; Young Kyung BAE
Journal of Pathology and Translational Medicine 2026;60(2):184-192
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.
3.A Prospective Cross-sectional Screening Using Non-mydriatic Fundus Photography and Optical Coherence Tomography in Patients on Tamoxifen Therapy
Sang Cheol YANG ; Jun Young LEE ; Dong Seon KIM ; Tae Yeon KIM ; Young Hwan JEONG ; Bo Hyun PARK ; IkSoo BYON ; Sung Who PARK
Journal of Retina 2026;11(1):44-49
Purpose:
To determine the prevalence of tamoxifen retinopathy and assess the utility of a screening protocol using non-mydriatic fundus photography and optical coherence tomography (OCT).
Methods:
Between May and October 2024, patients on tamoxifen therapy at a breast surgery clinic were offered screening including non-mydriatic fundus photography and OCT. Among those who consented, 290 patients (580 eyes) were included after excluding other retinal diseases. We investigated tamoxifen duration, cumulative dose, central retinal thickness, BMI, underlying diseases, menopausal status, and history of chemotherapy, hormone therapy, or oral contraceptives.
Results:
All patients were taking 20 mg of tamoxifen daily. The mean treatment duration was 55.7 ± 29.5 months for those treated longer than two years (n = 193), with a mean BMI of 22.1 ± 3.0 kg/m2. Systemic comorbidities included dyslipidemia (n = 27, 14.0%), hypertension (n = 19, 9.8%), diabetes mellitus (n = 13, 6.7%), and cardiovascular disease (n = 4, 2.1%). Additionally, patient histories included chemotherapy (n = 84, 43.7%), postmenopausal status (n = 56, 29.1%), hormone therapy (n = 52, 27.0%), and oral contraceptive use (n = 14, 7.2%). Tamoxifen retinopathy was not observed in any of the patients.
Conclusions
In this cross-sectional study, the prevalence of tamoxifen retinopathy, as assessed by non-mydriatic fundus photography and OCT in this study, was 0%, which is lower than previously reported rates (0.9%–12%). Although specialized examination by an ophthalmologist, including a dilated fundus examination and OCT remains the diagnostic gold standard, practical constraints can limit its routine clinical use. Our study evaluated a screening protocol performed without ophthalmologist intervention. However, we found that limitations in image quality compromised the detection of subtle lesions, such as crystalline deposits. Consequently, this approach may be insufficient to serve as a primary screening strategy.
4.An Analysis of Judicial Precedents on Medical Practice in Criminal Litigation in Obstetrics and Gynecology
Jeong Hyeon LEE ; Jun Won PARK ; Joon Cheol PARK ; Dong Ja KIM
Korean Journal of Medical Ethics 2026;29(1):31-47
This study analyzed 22 criminal cases involving obstetricians and gynecologists to identify legal trends and propose measures to reduce the legal burden on medical professionals while maintaining stable healthcare services. The cases were retrieved from the Supreme Court of Korea Judicial Information Disclosure Portal using keywords such as “obstetrics,” “gynecology,” “expectant mother,” “fetus,” “neonate,” “delivery,” “uterus,” and “placenta.” The cases were classified into two categories:medical malpractice (16 cases, 72.7%) and abortion and bioethics (6 cases, 27.3%). Guilty verdicts were issued in 8 cases (36.4%), whereas 14 cases (63.6%) resulted in acquittal. The qualitative analysis showed that courts consistently protected physicians’ clinical discretion in unpredictable and unavoidable situations, such as amniotic fluid embolism and uterine atony, provided that standard medical protocols were followed. Procedural appropriateness, rather than the perfection of clinical outcomes, appeared to be the primary basis for judicial protection. Although the judiciary acknowledges the inherent limitations of medical practice and tends to protect physicians when established guidelines are followed, the high frequency of criminal prosecution remains a substantial burden on healthcare providers and may threaten the sustainability of obstetric care.
5.Imaging-Detected Extranodal Extension in Head and Neck Cancer: Current Evidence, Standardized Grading, and Clinical Implications
Jeong Hyun LEE ; Dongjun LEE ; Young Jun CHOI
Korean Journal of Radiology 2026;27(4):356-362
Extranodal extension (ENE) of metastatic lymph nodes is a well-established adverse prognostic factor in head and neck cancer and has traditionally been confirmed pathologically. Imaging-detected ENE (iENE) enables pre-treatment assessment and provides prognostic information across different treatment settings. Recent studies and meta-analyses have demonstrated an independent association between iENE and adverse outcomes in both nasopharyngeal carcinoma (NPC) and human papillomavirus–positive oropharyngeal carcinoma, supporting its prognostic relevance, particularly in nonsurgical patient populations in whom pathological confirmation is unavailable. Growing evidence supporting the prognostic impact of iENE has influenced recent revisions to the American Joint Committee on Cancer 9th edition staging system, which now incorporates “advanced radiological ENE” as a criterion for the N3 category in NPC. However, the clinical interpretation of iENE remains constrained by substantial interobserver variability, heterogeneous imaging criteria, and an imperfect correlation with pathological ENE (pENE), underscoring the ongoing debate regarding its clinical validity. Recent international efforts have sought to standardize imaging definitions and grading systems for iENE, with the aim of reducing variability and facilitating more consistent application in clinical practice and research. This review summarizes the current evidence regarding the prognostic and diagnostic roles of iENE, outlines recent developments in its classification, and discusses future directions for its integration into risk-adapted treatment planning for head and neck cancer.
6.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.
7.Vitamin/mineral and non-vitamin/ non-mineral supplement use of breast cancer survivors in Korea
Jioh KANG ; Jiyoung YOUN ; Hyun Jeong CHO ; Hyeong-Gon MOON ; Dong-Young NOH ; So-Youn JUNG ; Eun Sook LEE ; Zisun KIM ; Hyun Jo YOUN ; Jihyoung CHO ; Young Bum YOO ; Se Kyung LEE ; Jeong Eon LEE ; Seok Jin NAM ; Jun Won MIN ; Yoo Seok KIM ; Jihyoun LEE ; Seho PARK ; Joon JEONG ; Jung Eun LEE
Nutrition Research and Practice 2026;20(2):333-345
BACKGROUND/OBJECTIVES:
Dietary supplement use is common among breast cancer survivors, but studies on Asian populations remain limited. This study investigated dietary supplement use among Korean breast cancer survivors, distinguishing between vitamin/ mineral (VM) and non-vitaminon-mineral (NVNM) supplements.
SUBJECTS/METHODS:
This cross-sectional study included 1,136 stage I–III breast cancer survivors from 12 Korean hospitals, who survived more than 6 mon post-surgery. The participants completed a questionnaire on post-diagnostic dietary supplement use. Stepwise logistic regression was applied, calculating odds ratios (ORs) and 95% confidence intervals (CIs) to identify the demographic and clinical factors associated with VM and NVNM use.
RESULTS:
Seventy percent of survivors reported supplement use, with 25% using a single product. The most common VM supplements were multivitamins/minerals, vitamin D, and vitamin C, while the most common NVNM supplements included omega-3 fatty acids, probiotics, and ginseng. Survivors with higher education and greater physical activity were more likely to use VM supplements (ORs [95% CIs], 2.74 [1.76–4.25] for college graduates or above vs. middle school or below; 1.38 [1.02–1.88] for the most active group vs. the least active group). NVNM use was associated with higher education, greater physical activity levels, and a history of smoking (ORs [95% CIs], 2.29 [1.46–3.58] for college graduates or above vs. middle school or below; 1.52 [1.13–2.06] for the most active group vs. the least active group; 2.00 [1.23–3.25] for ever smokers vs. never smokers). Survivors who had undergone chemotherapy were also more likely to use NVNM supplements than those who had not (OR [95% CI], 1.37 [1.02–1.84]).
CONCLUSION
Seventy percent of Korean breast cancer survivors used dietary supplements in this study. VM use was associated with higher education and physical activity, while higher NVNM use was associated with higher education, greater physical activity, a history of smoking, and chemotherapy.
8.Clinical Efficacy and Scalp Microbiome Changes Induced by AMPamide-Containing Shampoo in Patients With Seborrheic Dermatitis
Yi Na YOON ; Sae Hee KIM ; Ji Won LIM ; Myeong Jae KIM ; Hye-Jin KIM ; Woo Jun SUL ; Daehwan KIM ; Wonseok JEONG ; Jeonghwan HWANG ; Da-Ae YU ; Yong Beom CHOE ; Yang Won LEE
Annals of Dermatology 2026;38(3):237-247
Background:
Seborrheic dermatitis (SD) is a chronic inflammatory scalp disorder associated with Malassezia dysbiosis and increased sebum production. AMPamide has been suggested to have anti-inflammatory and sebum-regulating effects, but its clinical efficacy and microbiome-modulating effects in SD remain unclear.
Objective:
To evaluate the clinical efficacy and scalp microbiome changes following 4 weeks of use of an AMPamide-containing shampoo in patients with SD.
Methods:
In this observational study, 30 patients with SD applied an AMPamide-containing shampoo for 4 consecutive weeks. Clinical outcomes, including sebum levels and overall severity scores, were assessed. Scalp bacterial and fungal communities were analyzed to evaluate α- and β-diversity and changes in Malassezia composition.
Results:
Treatment resulted in significant reductions in sebum levels and clinical severity scores, particularly in erythema, dandruff, and pruritus. Bacterial community composition remained largely stable, while fungal α-diversity increased, and β-diversity analysis revealed a decrease in the ratio of Malassezia restricta to Malassezia globosa.
Conclusion
AMPamide-containing shampoo was associated with improved clinical symptoms and a shift toward a more balanced fungal community composition in patients with SD, supporting its potential as a non-steroidal therapeutic option for SD.
9.Improving prediction of ypT0–1N0 response in rectal cancer: the added value of gross tumor type to magnetic resonance tumor regression grade after chemoradiotherapy in a retrospective cohort study
Kyong-Min KANG ; Mi-Jeong CHOI ; Hong-min AHN ; Heung-Kwon OH ; Duck-Woo KIM ; Jungheum CHO ; Won CHANG ; Young Hoon KIM ; Kyoung Ho LEE ; Yu Kyung JUN ; Yonghoon CHOI ; Sung-Bum KANG
Annals of Surgical Treatment and Research 2026;110(4):237-245
Purpose:
While MRI-based tumor regression grade (mrTRG) has shown promise in evaluating pathologic response to concurrent chemoradiotherapy (CCRT) in rectal cancer, its ability to predict pathologic complete response remains limited.This study aimed to enhance mrTRG’s diagnostic performance in predicting ypT0–1N0 status, a key factor in considering non-radical management after CCRT for locally advanced rectal cancer (LARC).
Methods:
This retrospective study included 430 patients with LARC who underwent radical resection following CCRT at a single referral hospital between April 2018 and September 2024. Multivariable logistic regression was used to identify predictive factors associated with achieving ypT0–1N0 status. The diagnostic performances of mrTRG1–2 alone and in combination with other factors were assessed by comparing sensitivity, specificity, positive-predictive value (PPV), negative-predictive value, and area under the curve (AUC).
Results:
Ninety-three patients (21.6%) achieved ypT0–1N0. In the multivariable analysis, fungating type, cT1–2, and mrTRG1–2 were independent predictors for ypT0–1N0. Integrating mrTRG with gross tumor type yielded the highest AUC of 0.689 among the combined models. For predicting ypT0–1N0, the combination of mrTRG and gross tumor type improved PPV (79.2% vs. 41.5% for mrTRG alone) while also demonstrating enhanced sensitivity compared with ycT0–1N0, the conventional MRI-based predictor (40.9% vs. 22.6%).
Conclusion
This study demonstrated that combining mrTRG and gross tumor type improved the PPV of mrTRG in predicting ypT0–1N0 after CCRT in LARC. Further studies are warranted to validate the role of gross tumor type in refining predictive systems for selecting candidates for non-radical treatment.
10.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.

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