Sang Won Um
Samsung Medical Center
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Publication
Featured researches published by Sang Won Um.
Journal of Korean Medical Science | 2012
Byung Woo Jhun; Hye Yun Park; Kyeongman Jeon; Won Jung Koh; Gee Young Suh; Man Pyo Chung; Hojoong Kim; O Jung Kwon; Joungho Han; Sang Won Um
There are no accurate data on the relationship between nodal station and diagnostic performance of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). We evaluated the impact of nodal station and size on the diagnostic performance of EBUS-TBNA in patients with non-small cell lung cancer (NSCLC). Consecutive patients who underwent EBUS-TBNA of mediastinal or hilar lymph nodes for staging or diagnosis of NSCLC were included in this retrospective study. Between May 2009 and February 2010, EBUS-TBNA was performed in 373 mediastinal and hilar lymph nodes in 151 patients. The overall diagnostic sensitivity, specificity, accuracy and negative predictive value (NPV) of EBUS-TBNA were 91.6%, 98.6%, 93.8%, and 84.3%, respectively. NPV of the left side nodal group was significantly lower than those of the other groups (P = 0.047) and sensitivity of the left side nodal group tended to decrease (P = 0.096) compared with those of the other groups. Diagnostic sensitivity and NPV of 4L lymph node were 83.3% and 66.7%, respectively. However, diagnostic performances of EBUS-TBNA did not differ according to nodal size. Bronchoscopists should consider the impact of nodal stations on diagnostic performances of EBUS-TBNA.
Journal of pathology and translational medicine | 2016
Taebum Lee; Boram Lee; Yoon La Choi; Joungho Han; Myung Ju Ahn; Sang Won Um
Background: Although epidermal growth factor receptor (EGFR), v-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS), and anaplastic lymphoma kinase (ALK) mutations in non-small cell lung cancer (NSCLC) were thought to be mutually exclusive, some tumors harbor concomitant mutations. Discovering a driver mutation on the basis of morphologic features and therapeutic responses with mutation analysis can be used to understand pathogenesis and predict resistance in targeted therapy. Methods: In 6,637 patients with NSCLC, 12 patients who had concomitant mutations were selected and clinicopathologic features were reviewed. Clinical characteristics included sex, age, smoking history, previous treatment, and targeted therapy with response and disease-free survival. Histologic features included dominant patterns, nuclear and cytoplasmic features. Results: All patients were diagnosed with adenocarcinoma and had an EGFR mutation. Six patients had concomitant KRAS mutations and the other six had KRAS mutations. Five of six EGFR-KRAS mutation patients showed papillary and acinar histologic patterns with hobnail cells. Three of six received EGFR tyrosine kinase inhibitor (TKI) and showed partial response for 7–29 months. All six EGFR-ALK mutation patients showed solid or cribriform patterns and three had signet ring cells. Five of six EGFR-ALK mutation patients received EGFR TKI and/or ALK inhibitor and four showed partial response or stable disease, except for one patient who had acquired an EGFR mutation. Conclusions: EGFR and ALK mutations play an important role as driver mutations in double mutated NSCLC, and morphologic analysis can be used to predict treatment response.
Cancer Prevention Research | 2016
Tzu Fang Lou; Deepa Sethuraman; Patrick Dospoy; Pallevi Srivastva; Hyun Seok Kim; Joongsoo Kim; Xiaotu Ma; Pei Hsuan Chen; Kenneth Huffman; Robin E. Frink; Jill E. Larsen; Cheryl M. Lewis; Sang Won Um; Duk Hwan Kim; Jung Mo Ahn; Ralph J. DeBerardinis; Michael A. White; John D. Minna; Hyuntae Yoo
In order to identify new cancer-associated metabolites that may be useful for early detection of lung cancer, we performed a global metabolite profiling of a non–small cell lung cancer (NSCLC) line and immortalized normal lung epithelial cells from the same patient. Among several metabolites with significant cancer/normal differences, we identified a unique metabolic compound, N-acetylaspartate (NAA), in cancer cells—undetectable in normal lung epithelium. NAAs cancer-specific detection was validated in additional cancer and control lung cells as well as selected NSCLC patient tumors and control tissues. NAAs cancer specificity was further supported in our analysis of NAA synthetase (gene symbol: NAT8L) gene expression levels in The Cancer Genome Atlas: elevated NAT8L expression in approximately 40% of adenocarcinoma and squamous cell carcinoma cases (N = 577), with minimal expression in all nonmalignant lung tissues (N = 74). We then showed that NAT8L is functionally involved in NAA production of NSCLC cells through siRNA-mediated suppression of NAT8L, which caused selective reduction of intracellular and secreted NAA. Our cell culture experiments also indicated that NAA biosynthesis in NSCLC cells depends on glutamine availability. For preliminary evaluation of NAAs clinical potential as a circulating biomarker, we developed a sensitive NAA blood assay and found that NAA blood levels were elevated in 46% of NSCLC patients (N = 13) in comparison with age-matched healthy controls (N = 21) among individuals aged 55 years or younger. Taken together, these results indicate that NAA is produced specifically in NSCLC tumors through NAT8L overexpression, and its extracellular secretion can be detected in blood. Cancer Prev Res; 9(1); 43–52. ©2015 AACR.
Yonsei Medical Journal | 2012
Hye Yun Park; Cho Rom Hahm; Kyeongman Jeon; Won Jung Koh; Gee Young Suh; Man Pyo Chung; Hojoong Kim; O Jung Kwon; Sang Won Um
Purpose Vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) are major mediators of angiogenesis and are induced by tissue inflammation and hypoxia. The purpose of this study was to investigate whether serum VEGF and Ang-2 are associated with the presence of hemoptysis and the extent of systemic inflammation in patients with inflammatory lung diseases. Materials and Methods We prospectively enrolled 52 patients with inflammatory lung disease between June 2008 and October 2009. Results The median values of VEGF and Ang-2 were 436 pg/mL and 2383 pg/mL, respectively. There was a significant positive correlation between serum Ang-2 and VEGF levels. VEGF levels were not significantly different according to the presence of hemoptysis. C-reactive protein (CRP) and Ang-2 level were significantly higher in patients without hemoptysis (n=26) than in those with hemoptysis (n=26; p<0.001 and p<0.001, respectively). CRP and arterial oxygen tension (PaO2) were significantly correlated with both serum VEGF (p=0.032 and p=0.016, respectively) and Ang-2 levels (p<0.001 and p=0.041, respectively), after adjusting for other factors. Age and the absence of hemoptysis were factors correlated with serum Ang-2 levels Conclusion Our study suggests that serum VEGF and Ang-2 levels are associated with PaO2 and the severity of inflammation rather than the presence of hemoptysis in patients with inflammatory lung diseases. Thus, hemoptysis may not be mediated by increased serum levels of VEGF and Ang-2 in patients with inflammatory lung diseases, and further studies are required to determine the mechanisms of hemoptysis.
The Annals of Thoracic Surgery | 2009
Hae-Seong Nam; Sang Won Um; Won-Jung Koh; Gee Young Suh; Man Pyo Chung; O Jung Kwon; Jhingook Kim; Hojoong Kim
BACKGROUND The Y-shaped structure of the carinal bifurcation causes difficulties in the treatment of carinal stenosis. We describe a new Y-shaped silicone stent, called the Natural Y stent. We investigated its clinical efficacy through a review of patients with benign carinal stenosis who undewent consecutive Natural Y stent placement. METHODS Between January 2004 and February 2008, 11 patients underwent ballooning, neodymium:yttrium-aluminum-garnet laser resection, or bougienation (by rigid bronchoscopy) to dilate the airway, followed by placement of the Natural Y stent. RESULTS The underlying etiologies of carinal stenosis included posttuberculosis stricture in 7 patients (64%), postintubation stenosis in 2 (18%), and postoperative malacia in 2 (18%). All patients reported subjective symptomatic relief immediately after stent placement. No procedurally related deaths or immediate major complications occurred. Stent-related late complications included granulation tissue formation (64%) and mucostasis (18%, defined as > or = 50% narrowing). The median duration of overall stent placement was 439 days (range, 119 to 1729 days). The stents were successfully removed in 4 patients (36%) after a median of 409 days. CONCLUSIONS The Natural Y stent provides an effective and feasible therapeutic modality in patients with benign carinal stenosis, with or without previous thoracic airway interventions.
Korean Journal of Radiology | 2015
Mi Ri Kwon; Ho Yun Lee; Jong Ho Cho; Sang Won Um
Pulmonary vein (PV) stenosis is a complication of ablation therapy for arrhythmias. We report two cases with chronic lung parenchymal abnormalities showing no improvement and waxing and waning features, which were initially diagnosed as nonspecific pneumonias, and finally confirmed as PV stenosis. When a patient presents for nonspecific respiratory symptoms without evidence of infection after ablation therapy and image findings show chronic and repetitive parenchymal abnormalities confined in localized portion, the possibility of PV stenosis should be considered.
European Respiratory Journal | 2016
Sumin Shin; Hye Yun Park; Hyunkyung Kim; Hong Kwan Kim; Yong Soo Choi; Jhingook Kim; Sang Won Um; Myung Jin Chung; Hojoong Kim; O Jung Kwon; Eliseo Guallar; Juhee Cho; Young Mog Shim
This study aims to evaluate the joint effect of severity of airflow limitation and emphysema on postoperative pulmonary complications (PPCs) and overall survival after complete resection in patients with early-stage nonsmall cell lung cancer (NSCLC). We retrospectively studied 413 male patients with pathologic stage I or II NSCLC between 2007 and 2009. Severity of airflow limitation was defined based on forced expiratory volume in 1 s. Emphysema was defined by ≥5% low attenuation area at −950 HU. In multivariable-adjusted analyses, the adjusted odds ratio (aOR) for any PPC, comparing patients with moderate-to-severe airflow limitation to those without airflow limitation, was 2.23, and the aOR comparing patients with emphysema to those without emphysema was 1.77. However, the joint effect of airflow limitation and emphysema was much higher than expected from the independent effects of both factors (aOR 8.90). Moreover, patients with coexisting moderate-to-severe airflow limitation and emphysema had significantly poorer overall survival than any other group. Patients with moderate-to-severe airflow limitation and emphysema had almost nine times the risk of PPCs and poorer survival than patients with neither of these conditions. Integrated assessment of airflow limitation severity and emphysema is necessary for the optimal selection of candidates for lung resection surgery of early-stage NSCLC. Postoperative outcomes after complete resection in early-stage NSCLC depends on both airflow limitation and emphysema http://ow.ly/fAjl3049YKn
Hanyang Medical Reviews | 2014
Sang Won Um
Tuberculosis and Respiratory Diseases | 2011
Sang Won Um; Sang-Hee Lee; Hojoong Kim; O Jung Kwon; Hang-Rae Kim; Jae Seung Kang; Wang Jae Lee
대한결핵및호흡기학회 추계학술발표초록집 | 2011
Jun Whi Song; Kyung Jong Lee; Kyeong Man Jeon; Sang Won Um; Won Jung Koh; Gee Young Suh; Ho Joong Kim; O Jeong Kwon ; Man Pyo Chung