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.

Purpose: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Spinal melanocytoma (SMC) is a rare, slow-growing tumor arising from melanocytes in the spinal cord. We report a patient with a cervical intra- and extradural spinal tumor causing progressive weakness and numbness. On magnetic resonance imaging (MRI), the lesion showed intense homogeneous enhancement, similar to that seen in common neurogenic spinal tumors. After complete resection, pathological examination confirmed melanocytoma. A review of previously reported cases identified 26 reports of this tumor in the cervical spine, most of which were treated with complete surgical resection. Gross total resection is the preferred treatment, although radiation therapy may be considered when residual tumor remains. We report a 25-year-old male patient who presented with progressive weakness and numbness in both the upper and lower extremities for 3 months. MRI showed homogeneous enhancement. The mass compressed the spinal cord at C6–7 and extended through the neural foramen. Based on the MRI findings, spinal schwannoma was suspected preoperatively. Surgical resection was performed with laminectomy, durotomy, and right facetectomy. A dark-colored mass with well-demarcated margins was exposed and removed. Postoperative MRI confirmed complete removal of the mass. The patient recovered well, and his preoperative myelopathic symptoms gradually improved. SMC is a rare benign tumor that may be mistaken for schwannoma. The treatment of choice is gross total resection.

Previous studies have shown that testosterone activates the GPRC6A-Duox1 axis, resulting in the production of H 2O 2 which leads to the apoptosis of keratinocytes and ultimately hair loss. Here, we elucidated a molecular mechanism by which the non-genomic action of testosterone regulates cellular redox status in androgenetic alopecia (AGA). Building upon this molecular understanding, we conducted a high-throughput screening assay of Nox inhibitors from a natural compounds library. This screening identified diterpenoid compounds, specifically Tanshinone I, Tanshinone IIA, Tanshinone IIB, and Cryptotanshinone, derived from Salviae Miltiorrhizae Radix. The IC50 values for Nox isozymes were found to be 2.6-12.9 μM for Tanshinone I, 1.9-7.2 μM for Tanshinone IIA, 5.2-11.9 μM for Tanshinone IIB, and 2.1-7.9 μM for Cryptotanshinone. Furthermore, 3D computational docking analysis confirmed the structural basis by which Tanshinone compounds inhibit Nox activity. These compounds were observed to substitute for NADPH at the π-π bond site between NADPH and FAD, leading to the suppression of Nox activity. Notably, Tanshinone I and Tanshinone IIA effectively inhibited Nox activity heightened by testosterone, consequently reducing the production of intracellular H2O2 and preventing cell apoptosis. In an animal study involving the application of testosterone to the back skin of 8-week-old C57BL/6J mice to inhibit hair growth, subsequent treatment with Tanshinone I or Tanshinone IIA alongside testosterone resulted in a substantial increase in hair follicle length compared to testosterone treatment alone. These findings underscore the potential efficacy of Tanshinone I and Tanshinone IIA as therapeutic agents for AGA by inhibiting Nox activity.

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.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Previous studies have shown that testosterone activates the GPRC6A-Duox1 axis, resulting in the production of H 2O 2 which leads to the apoptosis of keratinocytes and ultimately hair loss. Here, we elucidated a molecular mechanism by which the non-genomic action of testosterone regulates cellular redox status in androgenetic alopecia (AGA). Building upon this molecular understanding, we conducted a high-throughput screening assay of Nox inhibitors from a natural compounds library. This screening identified diterpenoid compounds, specifically Tanshinone I, Tanshinone IIA, Tanshinone IIB, and Cryptotanshinone, derived from Salviae Miltiorrhizae Radix. The IC50 values for Nox isozymes were found to be 2.6-12.9 μM for Tanshinone I, 1.9-7.2 μM for Tanshinone IIA, 5.2-11.9 μM for Tanshinone IIB, and 2.1-7.9 μM for Cryptotanshinone. Furthermore, 3D computational docking analysis confirmed the structural basis by which Tanshinone compounds inhibit Nox activity. These compounds were observed to substitute for NADPH at the π-π bond site between NADPH and FAD, leading to the suppression of Nox activity. Notably, Tanshinone I and Tanshinone IIA effectively inhibited Nox activity heightened by testosterone, consequently reducing the production of intracellular H2O2 and preventing cell apoptosis. In an animal study involving the application of testosterone to the back skin of 8-week-old C57BL/6J mice to inhibit hair growth, subsequent treatment with Tanshinone I or Tanshinone IIA alongside testosterone resulted in a substantial increase in hair follicle length compared to testosterone treatment alone. These findings underscore the potential efficacy of Tanshinone I and Tanshinone IIA as therapeutic agents for AGA by inhibiting Nox activity.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Background: The positive relationship between triiodothyronine (T3) and steatotic liver disease (SLD) demonstrated only in crosssectional study. We aimed to evaluated whether total T3 (TT3) is associated with the development/resolution of SLD in longitudinal design. Methods: This retrospective, longitudinal, population-based cohort study included 1,665 South Korean euthyroid adults with ≥4 thyroid function test. We explored the impact of mean TT3 during follow-up on development/resolution of either SLD (diagnosed by ultrasound) or modified metabolic dysfunction-associated steatotic liver disease (MASLD) using Cox proportional hazards regression models. Results: During about median 5 years follow-up, 807/1,216 (66.3%) participants among participants without SLD at baseline developed SLD, and 253/318 (79.5%) participants among participants with SLD at baseline SLD resolved fatty liver. Mean TT3 rather than thyroid stimulating hormone or mean free thyroxine was significantly related with development (adjusted hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00 to 1.02; P=0.002) and resolution (adjusted HR, 0.97; 95% CI, 0.96 to 0.99; P=0.005) of SLD. Compared with low mean TT3 group, high mean TT3 group was positively associated with development of SLD (adjusted HR, 1.20; 95% CI, 1.05 to 1.38; P=0.008) and inversely associated with resolution of SLD (adjusted HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). The statistical significance remained for development (adjusted HR, 1.29; 95% CI, 1.10 to 1.51; P=0.001) and resolution (adjusted HR, 0.71; 95% CI, 0.54 to 0.94; P=0.018) of modified MASLD. Conclusion In Korean euthyroid adults, TT3 level was associated with development and resolution of either SLD or modified MASLD.

Previous studies have shown that testosterone activates the GPRC6A-Duox1 axis, resulting in the production of H 2O 2 which leads to the apoptosis of keratinocytes and ultimately hair loss. Here, we elucidated a molecular mechanism by which the non-genomic action of testosterone regulates cellular redox status in androgenetic alopecia (AGA). Building upon this molecular understanding, we conducted a high-throughput screening assay of Nox inhibitors from a natural compounds library. This screening identified diterpenoid compounds, specifically Tanshinone I, Tanshinone IIA, Tanshinone IIB, and Cryptotanshinone, derived from Salviae Miltiorrhizae Radix. The IC50 values for Nox isozymes were found to be 2.6-12.9 μM for Tanshinone I, 1.9-7.2 μM for Tanshinone IIA, 5.2-11.9 μM for Tanshinone IIB, and 2.1-7.9 μM for Cryptotanshinone. Furthermore, 3D computational docking analysis confirmed the structural basis by which Tanshinone compounds inhibit Nox activity. These compounds were observed to substitute for NADPH at the π-π bond site between NADPH and FAD, leading to the suppression of Nox activity. Notably, Tanshinone I and Tanshinone IIA effectively inhibited Nox activity heightened by testosterone, consequently reducing the production of intracellular H2O2 and preventing cell apoptosis. In an animal study involving the application of testosterone to the back skin of 8-week-old C57BL/6J mice to inhibit hair growth, subsequent treatment with Tanshinone I or Tanshinone IIA alongside testosterone resulted in a substantial increase in hair follicle length compared to testosterone treatment alone. These findings underscore the potential efficacy of Tanshinone I and Tanshinone IIA as therapeutic agents for AGA by inhibiting Nox activity.