• Journal of Gastric Cancer
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• v.21 no.3
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• pp.268-278
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• 2021

Purpose: While several prognostic models for the stratification of death risk have been developed for patients with advanced gastric cancer receiving first-line chemotherapy, they have seldom been tested in the Chinese population. This study investigated the performance of these models and identified the optimal tools for Chinese patients. Materials and Methods: Patients diagnosed with metastatic or recurrent gastric adenocarcinoma who received first-line chemotherapy were eligible for inclusion in the validation cohort. Their clinical data and survival outcomes were retrieved and documented. Time-dependent receiver operating characteristic (ROC) and calibration curves were used to evaluate the predictive ability of the models. Kaplan-Meier curves were plotted for patients in different risk groups divided by 7 published stratification tools. Log-rank tests with pairwise comparisons were used to compare survival differences. Results: The analysis included a total of 346 patients with metastatic or recurrent disease. The median overall survival time was 11.9 months. The patients were different into different risk groups according to the prognostic stratification models, which showed variability in distinguishing mortality risk in these patients. The model proposed by Kim et al. showed relative higher predicting abilities compared to the other models, with the highest χ² (25.8) value in log-rank tests across subgroups, and areas under the curve values at 6, 12, and 24 months of 0.65 (95% confidence interval [CI]: 0.59-0.72), 0.60 (0.54-0.65), and 0.63 (0.56-0.69), respectively. Conclusions: Among existing prognostic tools, the models constructed by Kim et al., which incorporated performance status score, neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, and tumor differentiation, were more effective in stratifying Chinese patients with gastric cancer receiving first-line chemotherapy.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.437-446
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• 2021

Objective : To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. Methods : A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics Results : Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017). Conclusion : Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.

• The Korean journal of internal medicine
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• v.33 no.6
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• pp.1111-1118
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• 2018

Background/Aims: Chest pain is an essential symptom in the diagnosis of acute coronary syndrome (ACS). One-third of patients with ACS present atypically, which can influence their receiving timely lifesaving therapy. Methods: A total of 617 NSTEMI patients from the Korea Acute MI Registry (KAMIR) and the Korea Working Group on MI (KorMI) databases were analyzed. The study population was divided into two groups by symptoms at presentation (typical symptoms group, 128; atypical symptoms groups, 128). Results: In this study population, 23% of patients presented without chest pain. After propensity score matching, the contact-to-device time ($2,618{\pm}381minutes$ vs. $1,739{\pm}241minutes$, p = 0.050), the symptoms-to-balloon time ($3,426{\pm}389minutes$ vs. $2,366{\pm}255minutes$, p = 0.024), and the door-to-balloon time ($2,339{\pm}380minutes$ vs. $1,544{\pm}244minutes$, p = 0.002) were significantly higher in the patients with atypical symptoms than in those with typical symptoms, respectively. Atypical symptoms were an independent predictor for 1-year mortality (hazard ratio, 2.820; 95% confidence interval, 1.058 to 7.515; p = 0.038). The Kaplan-Meier estimates showed higher risk for 12-month mortality in patients with atypical symptoms (p = 0.048) and no significant difference for 12-month major adverse cardiac events (p = 0.487). Conclusions: Acute myocardial infarction patients with atypical symptoms were not rare in clinical practice and showed a high risk of delayed reperfusion therapy. After imbalance between the groups was minimized by use of propensity score matching, patients who presented atypically had a high mortality rate.

• Journal of Breast Cancer
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• v.21 no.4
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• pp.382-390
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• 2018

Purpose: PIK3CA mutation is considered to be a possible cause for resistance to neoadjuvant chemotherapy (NAC) in human epidermal growth factor receptor 2 (HER2)-positive breast cancer. We investigated the association between PIK3CA mutations and the outcome of NAC in HER2-positive breast cancers. Methods: A total of 100 HER2-positive breast cancer patients who had undergone NAC and surgery between 2004 and 2016 were examined. Mutation status was sequentially assessed in pre-NAC, post-NAC, and recurrent specimens taken from these patients. Results: PIK3CA mutations were identified in the sequential specimens of 17 patients (17.0%). These 17 patients experienced shorter disease-free survival (DFS) than the rest of the patients (58.3 months vs. 119.3 months, p=0.020); however, there was no significant difference in pathologic complete response (pCR) and overall survival (OS) (pCR, 17.6% vs. 33.7%, p=0.191; OS, 84.5 months vs. 118.0 months, p=0.984). While there was no difference in pCR between the wild-type and mutant PIK3CA groups in pre-NAC specimens (25.0% vs. 31.8%, p=0.199), PIK3CA mutations correlated with lower pCR in postNAC specimens (0.0% vs. 24.3%, p<0.001). Multivariate analysis revealed significantly worse DFS in the mutant PIK3CA group than in the wild-type group (hazard ratio, 3.540; 95% confidence interval, 1.001-12.589; p=0.050). Moreover, the DFS curves of the change of PIK3CA mutation status in sequential specimens were significantly different (p=0.016). Conclusion: PIK3CA mutation in HER2-positive breast cancer was correlated with a lower pCR rate and shorter DFS. These results suggest that PIK3CA mutation is a prognostic marker for NAC in HER2-positive breast cancer, especially in post-NAC specimens.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.196-203
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• 2018

Purpose: The hemoglobin glycation index (HGI) represents the degree of nonenzymatic glycation and has been positively associated with cardiometabolic risk factors (CMRFs) and cardiovascular disease in adults. This study aimed to investigate the association between HGI, components of metabolic syndrome (MS), and alanine aminotransferase (ALT) in a pediatric nondiabetic population. Methods: Data from 3,885 subjects aged 10-18 years from the Korea National Health and Nutrition Examination Survey (2011-2016) were included. HGI was defined as subtraction of predicted glycated hemoglobin ($HbA1_c$) from measured $HbA1_c$. Participants were divided into 3 groups according to HGI tertile. Components of MS (abdominal obesity, fasting glucose, triglycerides, high-density lipoprotein cholesterol, and blood pressure), and proportion of MS, CMRF clustering (${\geq}2$ of MS components), and elevated ALT were compared among the groups. Results: Body mass index (BMI) z-score, obesity, total cholesterol, ALT, abdominal obesity, elevated triglycerides, and CMRF clustering showed increasing HGI trends from lower-to-higher tertiles. Multiple logistic regression analysis showed the upper HGI tertile was associated with elevated triglycerides (odds ratio, 1.65; 95% confidence interval, 1.18-2.30). Multiple linear regression analysis showed HGI level was significantly associated with BMI z-score, $HbA1_c$, triglycerides, and ALT. When stratified by sex, age group, and BMI category, overweight/obese subjects showed linear HGI trends for presence of CMRF clustering and ALT elevation. Conclusion: HGI was associated with CMRFs in a Korean pediatric population. High HGI might be an independent risk factor for CMRF clustering and ALT elevation in overweight/obese youth. Further studies are required to establish the clinical relevance of HGI for cardiometabolic health in youth.

• Asian Spine Journal
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• v.12 no.6
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• pp.973-980
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• 2018

Study Design: Retrospective review. Purpose: To identify the trends in stimulator use, pair those trends with various grafting materials, and determine the influence of stimulators on the risk of revision surgery. Overview of Literature: A large number of studies has reported beneficial effects of electromagnetic energy in healing long bone fractures. However, there are few clinical studies regarding the use of electrical stimulators in spinal fusion. Methods: We used insurance billing codes to identify patients with lumbar disc degeneration who underwent anterior lumbar interbody fusion (ALIF). Comparisons between patients who did and did not receive electrical stimulators following surgery were performed using logistic regression analysis, chi-square test, and odds ratio (OR) analysis. Results: Approximately 19% of the patients (495/2,613) received external stimulators following ALIF surgery. There was a slight increase in stimulator use from 2008 to 2014 (multi-level $R^2=0.08$, single-level $R^2=0.05$). Patients who underwent multi-level procedures were more likely to receive stimulators than patients who underwent single-level procedures (p<0.05; OR, 3.72; 95% confidence interval, 3.02-4.57). Grafting options associated with most frequent stimulator use were bone marrow aspirates (BMA) plus autograft or allograft for single-level and allograft alone for multi-level procedures. In both cohorts, patients treated with bone morphogenetic proteins were least likely to receive electrical stimulators (p<0.05). Patients who received stimulation generally had higher reimbursements. Concurrent posterior lumbar fusion (PLF) (ALIF+PLF) increased the likelihood of receiving stimulators (p<0.05). Patients who received electrical stimulators had similar revision rates as those who did not receive stimulation (p>0.05), except those in the multilevel ALIF+PLF cohort, wherein the patients who underwent stimulation had higher rates of revision surgery. Conclusions: Concurrent PLF or multi-level procedures increased patients' likelihood of receiving stimulators, however, the presence of comorbidities did not. Patients who received BMA plus autograft or allograft were more likely to receive stimulation. Patients with and without bone stimulators had similar rates of revision surgery.

• Journal of Trauma and Injury
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• v.32 no.3
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• pp.143-149
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• 2019

Purpose: No previous study has assessed elderly pedestrian traffic accidents based on a nationwide database. This study aimed to help primary physicians who examine patients in emergency departments to determine and make prompt and accurate treatment decisions. Methods: This study used data from the Emergency Department-based Injury Indepth Surveillance from 2013 to 2017, managed by the Korea Centers for Disease Control and Prevention. Pedestrians aged ${\geq}65years$ were included, and using multivariate logistic regression multiple factors were analyzed to determine their relationship with injury severity. Results: Of 227,695 subjects, 6,498 were included, of whom 2,065 (31.8%) were severely injured. There were more female than male patients in all severity groups. Most accidents occurred in the afternoon and on general roads. In the multivariate analysis, the odds ratio (OR) of injury severity for male pedestrians was 1.165 (95% confidence interval: 1.034-1.313, p=0.012). Older age of patients and the use of ambulances were associated with greater injury severity. The accident time affected the degree of injury severity; i.e., compared to dawn, injury severity increased in the morning (OR: 1.246, p=0.047) and decreased at night (OR: 0.678, p<0.001). A significant difference was noted in the correlation between the type of vehicle causing the accident and the accident severity; i.e., motorcycle accidents had lower severity than bicycle accidents (OR: 0.582, p=0.047). Conclusions: Injury severity was correlated with sex, age, transportation to the ED, TA onset time, and type of vehicle. The study results suggest that injury severity may be positively reflected in initial assessments and overall integrated treatments by physicians and in the related policies.

• Asian Spine Journal
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• v.12 no.6
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• pp.1085-1091
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• 2018

Study Design: Case-control. Purpose: To determine optimal cut-off value for body mass index (BMI) in predicting surgical success in patients with lumbar spinal canal stenosis (LSCS). Overview of Literature: BMI is an essential variable in the assessment of patients with LSCS. Methods: We conducted a prospective study with obese and non-obese LSCS surgical patients and analyzed data on age, sex, duration of symptoms, walking distance, morphologic grade of stenosis, BMI, postoperative complications, and functional disability. Obesity was defined as BMI of ${\geq}30kg/m^2$. Patients completed the Oswestry Disability Index (ODI) questionnaire before surgery and 2 years after surgery. Surgical success was defined as ${\geq}30%$ improvement from the baseline ODI score. Receiver operating characteristic (ROC) analysis was used to estimate the optimal cut-off values of BMI to predict surgical success. In addition, correlation was assessed between BMI and stenosis grade based on morphology as defined by Schizas and colleague in total, 189 patients were eligible to enter the study. Results: Mean age of patients was $61.5{\pm}9.6years$. Mean follow-up was $36{\pm}12months$. Most patients (88.4%) were classified with grades C (severe stenosis) and D (extreme stenosis). Post-surgical success was 85.7% at the 2-year follow-up. A weak correlation was observed between morphologic grade of stenosis and BMI. Rates of postoperative complications were similar between patients who were obese and those who were non-obese. Both cohorts had similar degree of improvement in the ODI at the 2-year followup. However, patients who were non-obese presented significantly higher surgical success than those who were obese. In ROC curve analysis, a cut-off value of ${\leq}29.1kg/m^2$ for BMI in patients with LSCS was suggestive of surgical success, with 81.1% sensitivity and 82.2% specificity (area under the curve, 0.857; 95% confidence interval, 0.788-0.927). Conclusion: This study showed that the BMI can be considered a parameter for predicting surgical success in patients with LSCS and can be useful in clinical practice.

• Tuberculosis and Respiratory Diseases
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• v.82 no.3
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• pp.227-233
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• 2019

Background: Programmed death-ligand 1 (PD-L1), a transmembrane protein, binds to the programmed death-1 (PD-1) receptor, and anti-PD-1 therapy enables immune responses against tumors. This study aimed to assess clinical characteristics of PD-L1 expression using immunohistochemistry among Korean patients with lung cancer. Methods: We retrospectively reviewed the data of patients with pathologically proven lung cancer from a single institution. PD-L1 expression determined by Tumor Proportion Score (TPS) was detected using 22C3 pharmDx (Agilent Technologies) and SP263 (Ventana Medical Systems) assays. Results: From July 2016 to July 2017, 267 patients were enrolled. The main histologic type was adenocarcinoma (69.3%). Most participants were smokers (67.4%) and had clinical stage IV disease (60.7%). In total, 116 (42%) and 58 (21%) patients had TPS ${\geq}1%$ and ${\geq}50%$, respectively. The patients were significantly older in TPS ${\geq}1%$ group than in TPS <1% group ($64.83{\pm}9.38years$ vs. $61.73{\pm}10.78years$, p=0.014), not in TPS ${\geq}50%$ cutoff value ($64.69{\pm}9.39$ vs. $62.36{\pm}10.51$, p=0.178). Regarding histologic grade, higher proportions of poorly differentiated tumor were observed in the TPS ${\geq}1%$ (40.8% vs. 25.8%, p=0.020) and TPS ${\geq}50%$ groups (53.2% vs. 27.2%, p=0.004). Among 34 patients examined with 22C3 and SP263 assays, 27 had positive results in both assays, with a cutoff of TPS ${\geq}1%$ (r=0.826; 95% confidence interval, 0.736-0.916). Conclusion: PD-L1 expression, defined as TPS ${\geq}1%$, was related to older age and poorly differentiated histology. There was a similar distribution of PD-L1 expression in both 22C3 and SP263 results.

• Tuberculosis and Respiratory Diseases
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• v.82 no.3
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• pp.251-260
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• 2019

Background: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. Methods: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). Results: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen ($FiO_2$) ratio was higher (97 vs. 61, p<0.001) while the median $FiO_2$ was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02-0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. Conclusion: Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.