Background and Objectives: Anti-adhesion agents based on hyaluronate-carboxymethyl cellulose (HA-CMC) are widely used in thyroid surgery to reduce postoperative adhesions. However, concerns persist that higher application volumes may increase postoperative drainage and prolong hospitalization. This study aimed to evaluate the impact of different doses of an HA-CMC solution (Guardix-SGⓇ ) on postoperative drainage and clinical outcomes after hemithyroidectomy. Materials and Methods: This prospective study included 107 patients who underwent hemithyroidectomy with central neck lymph node dissection for thyroid cancer between January and October 2024. Patients were randomly assigned to receive either 3 g (n=57) or 6 g (n=50) of Guardix-SGⓇ intraoperatively.Postoperative drainage volume, drain duration, and length of hospital stay were compared between groups.Analysis of covariance and quantile regression were performed to assess the effects of HA-CMC dose and clinical covariates on drainage outcomes. Results: Baseline demographic and pathological characteristics were comparable between the two groups. Total postoperative drainage volume did not differ significantly between the 3 g and 6 g groups, even after adjustment for hospital stay (p=0.283), nor did drain duration. Quantile regression analysis revealed that hypertension was independently associated with increased drainage volume in higher quantiles (0.25– 0.75), whereas the dose of HA-CMC solution had no significant effect across any quantile. Conclusion Application of a higher dose (6 g) of HA-CMC solution did not increase postoperative drainage or prolong drain duration after hemithyroidectomy. These findings support the safe and effective use of higher-dose Guardix-SGⓇ in thyroid surgery.

Purpose: Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive subtype of breast cancer associated with poor clinical outcomes. Although programmed death ligand 1 (PD-L1) expression has emerged as both a prognostic and predictive biomarker, its utility remains limited, especially in PD-L1-negative tumors. The identification of additional molecular markers is crucial for improving prognostic stratification and guiding treatment strategies. Methods: Formalin-fixed, paraffin-embedded tumor tissues from 38 patients with TNBC were analyzed. PD-L1 expression was assessed using immunohistochemistry and categorized as positive or negative. Whole-exome sequencing was performed, and somatic variants were analyzed using Maftools. Mutational signatures were compared with the Catalogue Of Somatic Mutations In Cancer reference profiles. Survival analyses were performed to evaluate the prognostic significance of the identified variants. Results: Mutational landscape analysis revealed that C>T and G>A transitions were the most frequent base substitutions. PD-L1-negative tumors exhibited a predominance of single-base substitution (SBS) 5, whereas PD-L1-positive tumors resembled SBS6, reflecting potential differences in the underlying mutational processes. Comparative analysis identified 12 PD-L1-negative-specific and seven PD-L1-positive-specific variants. Among PD-L1-negative tumors, mutations in ANGPTL5 and KIAA1549L were significantly associated with worse overall survival. Conclusion Our findings highlight distinct mutational profiles and prognostic variants according to PD-L1 status in TNBC. ANGPTL5 and KIAA1549L variants may serve as potential prognostic markers for PD-L1-negative tumors. These results underscore the value of incorporating genomic information to refine the prognostic stratification of TNBC.

Objective: The purpose of this study was to develop a machine learning-based model (eXtreme Gradient boost [XGBoost]) that can accurately predict the severity of acute cholangitis in patients. The model was designed to simplify the classification process compared to conventional methods. Methods: We retrospectively collected data from patients with cholangitis who visited the emergency department of a secondary medical institution in Seongnam, Korea from January 1, 2015 to December 31, 2019. The patients were divided into three groups (Grade I, II, III) based on severity according to the Tokyo Guidelines 2018/2013 (TG18/13) severity assessment criteria for cholangitis. We used algorithms to select variables of high relevance associated with the grade of severity. For the XGBoost models, data were divided into a train set and a validation set by the random split method. The train set was trained in XGBoost models using only the top seven variables. The area under the receiver operating characteristic (AUROC) and the area under the precision-recall curve (AUPRC) were obtained from the validation set. Results: 796 patients were enrolled. The top 7 variables associated with the grade of severity were albumin, white blood cells, blood urea nitrogen, troponin T, platelets, creatinine, prothrombin time, and international normalized ratio. The AUROC values were 0.881 (Grade I), 0.836 (Grade II), and 0.932 (Grade III). The AUPRC values were 0.457 (Grade I), 0.820 (Grade II), and 0.880 (Grade III). Conclusion We believe that the developed XGBoost model is a useful tool for predicting the severity of acute cholangitis with high accuracy and fewer variables than the conventional severity classification method.

Objective: This study examined the predictive factors to decide the surgical treatment for clinically suspected pediatric acute appendicitis with equivocal imaging findings. Methods: This study was conducted retrospectively on children who visited local emergency medical centers and outpatients from January 2018 to February 2021. The electronic medical records were reviewed from 811 pediatric patients younger than 16 years of age with the chief complaint of abdominal pain and who underwent an imaging test for the clinical suspicion of appendicitis. Ninety-two patients who showed ambiguous findings on imaging tests but were still suspected of having appendicitis were analyzed. Recursive partitioning analysis and multivariable logistic regression were used to identify the variables associated with appendicitis. Results: Of the 92 enrolled patients, 23 patients were confirmed to have appendicitis, and 69 did not. Patients with the clinical suspicion who had an elevated white blood cell (WBC) count, polymorphonuclear leukocyte differential count (PMN), absolute neutrophil count (ANC), and leukocytosis were more likely to have appendicitis. The PMN (odds ratio=1.175; 95% confidence interval, 1.092-1.265) and ANC (odds ratio=1.00050; 95% confidence interval, 1.00025-1.00075) remained significant after multivariable logistic analysis. Conclusion Elevated PMN and ANC are clinical predictors of pediatric appendicitis when the imaging findings are nondiagnostic, and the clinical suspicion is continuous.

Purpose: Several studies are concerned about the association between bone mineral density (BMD) and the risk of breast cancer in postmenopausal women, but it is controversial. Therefore, we evaluated whether BMD might be a risk factor for recurrences, or metastases in menopausal luminal A breast cancer patients. Methods: In this retrospective study, data of 348 patients with luminal A breast cancer who received treatment at Pusan National University Yangsan Hospital between 2012 and 2016 were analyzed. Patients were divided into two groups: normal BMD and low BMD including osteopenia or osteoporosis in preoperative examination. Patients were also divided into three groups according to BMD changes: no change in BMD; improvement in BMD, and deterioration in BMD. Events were defined as recurrence, occurrence of contralateral breast cancer, and metastasis to any other organ. Results: Preoperative examination revealed normal BMD in 129 of 348 patients and low BMD in 219 patients. During a median follow-up period of 78 months, only 14 patients (4.0%) experienced recurrences, distant metastases, or occurrences of contralateral breast cancer. Five-year disease-free survival rate was 98.2% for 219 patients with low BMD and 95.0% for 129 patients with normal BMD (P=0.33). Disease-free survival at 5 years was 97.0% for the no change in the BMD group, 94.6% for the BMD improvement group, and 98.4% for the BMD deterioration group (P=0.79). Conclusion In this study, BMD had no statistically significant associations on recurrences, metastases, or incidences of contralateral breast cancer in postmenopausal patients with luminal A breast cancer.

Background: Recessive dystrophic epidermolysis bullosa (RDEB) manifests in various cutaneous and extracutaneous complications that lead to considerable morbidity and mortality, however, no precise incidence data are available. Objective: To investigate the prevalence of inherited epidermolysis bullosa (EB) stratified by subtypes, demographics, and clinical characteristics in Korean patients with EB, and major clinical events and outcomes in Korean RDEB patients. Methods: A total of 179 patients diagnosed with EB at a single tertiary hospital between January 2005 and January 2020 were retrospectively analyzed. Results: Among the 179 patients, 86 (48.0%) had EB simplex, 45 (25.1%) had dominant dystrophic EB, 38 (21.2%) had RDEB, and 10 (5.6%) had juncttional EB. Symptoms of the disease were present at age 1 year in 38 patients with RDEB (100%), 10 with junctional EB (100%), 41 with dominant dystrophic EB (91.1%), and 63 with EB simplex (73.3%). Among the 38 patients with RDEB, 20 (52.6%) had anemia, 21 (55.3%) had pseudosyndactyly, 9 (23.7%) had cardiac disorder (23.7%) (e.g., dilated cardiomyopathy), 9 (23.7%) had ophthalmic disorders, 11 (28.9%) had methicillin-resistant Staphylococcus aureus skin infection, 7 (18.4%) had esophageal stricture, and 4 (10.5%) developed squamous cell carcinoma at a mean age of 46.7 years. Seventeen subjects (44.7%) underwent hand/foot surgery at a mean age of 6.6 years. Six subjects (15.8%) underwent esophageal dilation at a mean age of 23 years. Five patients (13.2%) died. Conclusion RDEB affects multiple organ systems and requires a multidisciplinary therapeutic approach. Understanding the incidence and outcomes of milestone clinical events is crucial for optimal management of RDEB patients.

Objective: This study analyzed the urine cultures of emergency department patients diagnosed with acute uncomplicated cystitis and determined the antimicrobial resistance and appropriate treatment for our region. Methods: Results of urine analysis and urine culture of acute uncomplicated cystitis patients diagnosed in our emergency department between January 2019 and December 2020 were examined and analyzed. Results: In our study, 256 out of 340 urine culture samples (75.3%) were positive for cystitis. The most common microorganism was reported to be Escherichia coli (93.0%). The resistance rates of E. coli to the following antimicrobial agents were as follows: amikacin (0.0%), ampicillin (63.5%), amoxicillin/clavulanate (15.6%), aztreonam (7.1%), ceftazidime (3.4%), cefotaxime (16.4%), cefoxitin (5.5%), cefazolin (19.9%), ciprofloxacin (29.4%), cefepime (1.7%), ertapenem (0.0%), gentamicin (18.1%), piperacillin/tazobactam (2.1%), trimethoprim/sulfamethoxazole (36.1%), and tigecycline (0.4%). The prevalence of extended-spectrum beta-lactamase producing E. coli strains was 17.8%. Conclusion To determine the proper empirical antimicrobial treatment for acute uncomplicated cystitis, it is essential to examine the antimicrobial resistance. For our region, fosfomycin, nitrofurantoin, and 2nd and 3rd generation cephalosporin should be considered the first-line empirical treatment for acute uncomplicated cystitis.

Purpose: The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. Methods: This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. Results: Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). Conclusion This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

Purpose: The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. Methods: This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. Results: Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). Conclusion This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

Purpose: Breast conserving surgery (BCS) is generally not considered for breast cancer because of concerns about the poor prognosis of triple negative breast cancer (TNBC). We assessed the outcomes of BCS and mastectomy for patients with stage II-IIIA TNBC. Methods: The data of 172 breast cancer patients diagnosed with stage II-IIIA TNBC who underwent treatment at Pusan National University Hospital and Pusan National University Yangsan Hospital from 2010 to 2014 were retrospectively analyzed. The patients were divided into the following two groups: patients who underwent BCS (n=101) and those who underwent mastectomy (n=71). The Cox regression model was used to examine the outcomes of both treatments. The median follow-up period was 71 months in the BCS group, and 67 months in the mastectomy group. Results: The median age of the 172 patients was 51 years (range, 22-82 years). In the BCS group, radiation therapy and chemotherapy (p<0.001 and p=0.007, respectively) were performed more frequently. The BCS group had more patients with a high Ki-67 index (p=0.006), while the mastectomy group included more patients with a higher pathologic T (pT) stage (p=0.005). The 5-year loco-regional recurrence-free, disease-free, and overall survival rates of the BCS group versus the mastectomy group were 93.8% versus 95.3%, 89.8% versus 90.7%, and 90.8% versus 86.3%, respectively, but the differences were not statistically significant. Lymphovascular invasion was a risk factor for disease-free survival and advanced stage was an important risk factor for overall survival. Conclusion In stage II-IIIA TNBC, BCS was not inferior to mastectomy in locoregional recurrence rates, disease-free survival rates, or overall survival rates.