Background/Aims: Spinal cord injury (SCI) frequently impairs defecation, severely affecting the quality of life. This study examines compensatory neural remodeling after SCI, focusing on basal colonic contractility, neural responses to electrical field stimulation, and alterations in excitatory cholinergic and inhibitory nitrergic pathways. Methods: Female Sprague–Dawley rats underwent either sham surgery or T10 spinal cord transection and were categorized into 3 groups: sham, 1-week post-SCI (acute), and 4-week post-SCI (chronic). Colonic contractility was assessed in an organ bath using electrical field stimulation in the presence of a nitric oxide synthase inhibitor. Neural protein expression was analyzed by immunofluorescence and Western blotting. Results: SCI produced region- and time-dependent impairments in colonic contractility, with distinct alterations in the proximal circular and longitudinal muscles across acute and chronic phases. Neural excitability shifted dynamically, showing enhanced excitatory activity in the proximal longitudinal muscle at 1-week and the distal circular muscle at 4-week post-SCI. Protein analysis revealed increased neuronal nitric oxide synthase in the proximal colon, decreasedsoluble guanylyl cyclase in the distal colon, upregulated muscarinic M3 receptor in the proximal colon, and reduced vaso-active intestinal peptide receptor 1 in both proximal and distal regions. Conclusion SCI induces spatiotemporal remodeling of excitatory and inhibitory neural pathways, contributing to colonic dysmotility and revealing potential targets for therapeutic intervention.

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.

Purpose: Human epidermal growth factor receptor 2 (HER2) is amplified or overexpressed in various malignancies, including breast and gastric cancers, and is associated with poor prognosis. Although HER2-targeted therapies, such as trastuzumab, improve outcomes in HER2-positive tumors, resistance often develops, and HER2-low tumors remain largely untargeted. Trastuzumab deruxtecan (T-DXd; DS-8201a) is a HER2-targeted antibody-drug conjugate with potent activity in HER2-positive and HER2-low tumors. This study evaluates its antitumor mechanisms and efficacy in HER2-positive, HER2-low, and homologous recombination deficiency (HRD)–associated models. Materials and Methods: Effects of T-DXd were assessed in cancer cell lines with diverse HER2 expression and HRD status. In vivo efficacy was evaluated using a xenograft model derived from HER2-low SNU-601 gastric cancer cells. Results: T-DXd reduced HER2 phosphorylation and downstream signaling (AKT, ERK) in HER2-positive cells. It induced DNA damage accumulation, as evidenced by increased γH2AX and p-Chk1 expression, and triggered apoptosis through cleaved poly(ADP-ribose) polymerase and caspase-3 activation, confirmed by annexin V staining. Similar effects were observed in HER2-low cells, with greater sensitivity in HRD cells. In xenografts, T-DXd reduced tumor volume by up to 80% at 4 mg/kg and 10 mg/kg. Histological analyses showed decreased Ki-67 and increased apoptosis. Furthermore, T-DXd induced G2/M cell cycle arrest and nuclear anaplasia, suggesting disruption of chromosomal stability as a potential antitumor mechanism. No significant toxicity, including body weight loss, was observed. Conclusion These findings highlight T-DXd’s effectiveness in HER2-low and HRD tumors, supporting its broader clinical application, including strategies targeting DNA damage repair pathways.

Purpose: Sustained cell proliferation and cell cycle acceleration in cancer cells inherently increase DNA damage, which interferes with homeostatic replication and transcription. Ataxia telangiectasia and Rad3-related (ATR) is crucial for initiation of the DNA damage response, and ATR inhibitors, such as elimusertib, induce increased replication stress and DNA damage. We investigated the anti-tumor effects of elimusertib and its mechanism of action in relation to replication stress. Materials and Methods: Anti-tumor effects were evaluated by MTT assay and colony formation assay in breast cancer cell lines in vitro, in breast cancer cell xenografts in vivo, and in patient-derived xenograft models. Cell cycle was assessed by flow cytometry and BrdU assay was used to measure replicating cells and S-phase progression. Alkaline and neutral comet assay was used to measure single and double-stranded DNA damages, respectively. Results: Elimusertib delayed S-phase progression in MDA-MB-453 and MDA-MB-231 cells and induced caspase-7–dependent apoptosis. Furthermore, the increase in sub-G1 population in the fluorescence-activated cell sorting analysis and Annexin V assay also confirmed apoptotic cell death. In the BrdU assay, single-stranded DNA (ssDNA) increased in sensitive cells and aberrant ssDNA induced DNA damage in S-phase and eventually caused replication catastrophe. Finally, these anti-tumor effects were proven in in vivo xenograft and patient-derived xenograft models. Conclusion Elimusertib had anti-tumor effects and induced replication catastrophe in breast cancer cells with a high replication rate. Moreover, cells under high DNA replication stress were sensitive to elimusertib. Further studies and treatment strategies with elimusertib are warranted for cancers with a high replication rate.

Purpose: The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex. Materials and Methods: Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed. Results: Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males. Conclusion Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.

Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.

Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly. Methods: We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease. Results: During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001). Conclusion In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.

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.

Purpose: While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer. Methods: Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses. Results: Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups. Conclusion This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.