Objectives: This study, part of the ongoing Korean National Burden of Disease (KNBD) updates, assesses disability-adjusted life years (DALYs) and disability-adjusted life expectancy (DALE) in Korea, taking into account the effects of coronavirus disease 2019 and emphasizing the importance of analyzing these metrics jointly. Methods: Data were obtained from Statistics Korea, the National Health Insurance Service, and the Korea Disease Control and Prevention Agency. DALYs and DALE were calculated using an incidence-based approach, following disease classification, disability weights, and estimation procedures consistent with prior KNBD research. Results: Compared with earlier estimates, DALYs showed a slight decline in 2020 followed by an increase in 2021, with this pattern observed across all income quintiles. For DALE, both men and women experienced modest gains relative to earlier studies; however, a decrease occurred across all income levels in 2021 compared with 2020. Regional disparities in DALE also narrowed beginning in 2020, with a more marked reduction among women. Conclusions Unlike previous studies, this research presents DALYs and DALE concurrently, offering a more comprehensive perspective on summary measures of population health. The post-2020 rise in DALYs underscores the growing need for effective chronic disease management. Additionally, widening income-based disparities in DALE highlight the urgency of addressing health inequities. Continued monitoring and updates of DALYs and DALE are necessary to understand and respond to these evolving trends.

Background: Epidermal growth factor (EGF) is widely applied in dermatology for its regenerative effects; however, its clinical utility is limited by low stability and high production costs.To overcome these limitations, we developed a novel probiotic-derived epidermal growth factor (pEGF) by engineering Pediococcus pentosaceus CBT SL4 to express and secrete EGF. Objective: To investigate the anti-photoaging effects of topical pEGF in a ultraviolet B (UVB)-irradiated mice by assessing histological and molecular changes related to collagen synthesis, extracellular matrix (ECM) remodeling, oxidative stress, and inflammation. Methods: SKH1 hairless mice were exposed to UVB for twelve weeks to induce photoaging and treated with topical 10% pEGF cream from week 9 to 12. Skin samples were analyzed using dermoscopy, histology, immunohistochemistry, quantitative real-time polymerase chain reaction, western blotting, and proteomics to evaluate morphological and molecular alterations in ECM components and inflammatory markers. Results: Topical pEGF treatment improved skin texture and reduced wrinkles. Histological evaluation revealed that EGF significantly attenuated UVB-induced epidermal thickening and restored collagen density, with the strongest effects observed in the pEGF group. Molecular analysis showed downregulation of matrix metalloproteinases (MMPs; MMP-1, MMP-3), upregulation of collagen (type I collagen, type III collagen) and tissue inhibitors of metalloproteinases (TIMPs; TIMP-1, TIMP-2). Additionally, pEGF reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β) and oxidative stress markers. Conclusion pEGF demonstrated potent anti-photoaging effects through ECM restoration, inflammation modulation, and barrier reinforcement. These findings support the therapeutic potential of pEGF as a stable, cost-effective alternative to conventional EGF in dermatological applications.

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.

In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Background: The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction. Methods: We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected. Results: Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures. Conclusions Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction. Methods: We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected. Results: Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures. Conclusions Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction. Methods: We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected. Results: Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures. Conclusions Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.