Sun Hye Shin

Comorbidity as a contributor to frequent severe acute exacerbation in COPD patients.

Background Comorbidities have a serious impact on the frequent severe acute exacerbations (AEs) in patients with COPD. Previous studies have used the Charlson comorbidity index to represent a conglomerate of comorbidities; however, the respective contribution of each coexisting disease to the frequent severe AEs remains unclear. Methods A retrospective, observational study was performed in 77 COPD patients who experienced severe AE between January 2012 and December 2014 and had at least 1-year follow-up period from the date of admission for severe AE. We explored the incidence of frequent severe AEs (≥2 severe AEs during 1-year period) in these patients and investigated COPD-related factors and comorbidities as potential risk factors of these exacerbations. Results Out of 77 patients, 61 patients (79.2%) had at least one comorbidity. During a 1-year follow-up period, 29 patients (37.7%) experienced frequent severe AEs, approximately two-thirds (n=19) of which occurred within the first 90 days after admission. Compared with patients not experiencing frequent severe AEs, these patients were more likely to have poor lung function and receive home oxygen therapy and long-term oral steroids. In multiple logistic regression analysis, coexisting asthma (adjusted odds ratio [OR] =4.02, 95% confidence interval [CI] =1.30–12.46, P=0.016), home oxygen therapy (adjusted OR =9.39, 95% CI =1.60–55.30, P=0.013), and C-reactive protein (adjusted OR =1.09, 95% CI =1.01–1.19, P=0.036) were associated with frequent severe AEs. In addition, poor lung function, as measured by forced expiratory volume in 1 second (adjusted OR =0.16, 95% CI =0.04–0.70, P=0.015), was inversely associated with early (ie, within 90 days of admission) frequent severe AEs. Conclusion Based on our study, among COPD-related comorbidities, coexisting asthma has a significant impact on the frequent severe AEs in COPD patients.

Risk factors for post-operative venous thromboembolism in patients with a malignancy of the lower limb

It is important to be able to identify patients with an increased risk of venous thromboembolism (VTE) in order to minimise the risk of an event. We investigated the incidence and risk factors for post-operative VTE in 168 consecutive patients with a malignancy of the lower limb. The period of study included ten months before and 12 months after the introduction of chemical thromboprophylaxis. All data about the potential risk factors were identified and classified into three groups (patient-, surgery- and tumour-related). The outcome measure was a thromboembolic event within 90 days of surgery. Of the 168 patients, eight (4.8%) had a confirmed symptomatic deep-vein thrombosis and one (0.6%) a fatal pulmonary embolism. Of the 28 variables tested, age > 60 years, higher American Society of Anesthesiologists grade and metastatic tumour were independent risk factors for VTE. The overall rate of symptomatic VTE was not significantly different between patients who received chemical thromboprophylaxis and those who did not. Knowledge of these risk factors may be of value in improving the surgical outcome of patients with a malignancy of the lower limb.

Nontuberculous Mycobacterial Lung Disease Caused by Mycobacterium simiae: The First Reported Case in South Korea

This is a report of the first South Korean case of a lung disease caused by Mycobacterium simiae. The patient was a previously healthy 52-year-old female. All serial isolates were identified as M. simiae by multi-locus sequencing analysis, based on hsp65, rpoB, 16S-23S rRNA internal transcribed spacer, and 16S rRNA fragments. A chest radiography revealed deterioration, and the follow-up sputum cultures were persistently positive, despite combination antibiotic treatment, including azithromycin, ethambutol, and rifampin. To the best of our knowledge, this is the first confirmed case of a lung disease caused by M. simiae in South Korea.

Severity of Airflow Obstruction and Work Loss in a Nationwide Population of Working Age

The impact of COPD severity on labor force participation and work loss is not well known. This study aimed to describe the characteristics of occupations and to evaluate the reason for work loss based on the severity of airflow obstruction (AO). We performed a cross-sectional study using data from the Korean National Health and Nutrition Examination Survey V−VI. We identified 9,901 people aged 40 to 60 years who had normal or AO in spirometry test results. AO was defined as a pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity <70%. AO was present in 7.6% of the subjects, and 81.5%, 82.9%, and 71.6% of subjects with mild, moderate, and severe-to-very severe AO were in the labor force, respectively. Multivariable analyses revealed that severe-to-very severe AO subjects were more likely to have precarious job (adjusted OR = 4.71, 95% CI = 1.70–13.06) and cite health-related problem as the reason for not being in the labor force (adjusted OR = 3.38, 95% CI = 1.03–11.02). Overall, AO was not associated with any significant changes in labor force participation. However, subjects with severe-to-very severe disease were more likely to drop out of the labor force owing to their health-related problems.

Comparison of four models predicting the malignancy of pulmonary nodules: A single-center study of Korean adults

Objective Four commonly used clinical models for predicting the probability of malignancy in pulmonary nodules were compared. While three of the models (Mayo Clinic, Veterans Association [VA], and Brock University) are based on clinical and computed tomography (CT) characteristics, one model (Herder) additionally includes the 18F-fluorodeoxyglucose (FDG) uptake value among the positron emission tomography (PET) characteristics. This study aimed to compare the predictive power of these four models in the context of a population drawn from a single center in an endemic area for tuberculosis in Korea. Methods A retrospective analysis of 242 pathologically confirmed nodules (4–30 mm in diameter) in 242 patients from January 2015 to December 2015 was performed. The area under the receiver operating characteristic curve (AUC) was used to assess the predictive performance with respect to malignancy. Results Of 242 nodules, 187 (77.2%) were malignant and 55 (22.8%) were benign, with tuberculosis granuloma being the most common type of benign nodule (23/55). PET was performed for 227 nodules (93.8%). The Mayo, VA, and Brock models showed similar predictive performance for malignant nodules (AUC: 0.6145, 0.6042 and 0.6820, respectively). The performance of the Herder model (AUC: 0.5567) was not significantly different from that of the Mayo (vs. Herder, p = 0.576) or VA models (vs. Herder, p = 0.999), and there were no differences among the three models in determining the probability of malignancy of pulmonary nodules. However, compared with the Brock model, the Herder model showed a significantly lower ability to predict malignancy (adjusted p = 0.0132). Conclusions In our study, the Herder model including the 18FDG uptake value did not perform better than the other models in predicting malignant nodules, suggesting the limited utility of adding PET/CT data to models predicting malignancy in populations within endemic areas for benign inflammatory nodules, such as tuberculosis.

Anaplastic lymphoma kinase rearrangement in surgically resected stage IA lung adenocarcinoma

Background It has not been determined if adjuvant chemotherapy would be helpful for completely resected early-stage lung adenocarcinoma even with unfavorable genetic markers. As the positive anaplastic lymphoma kinase (ALK) rearrangement is associated with aggressive clinical feature in lung adenocarcinoma, we evaluated the treatment outcomes of completely resected stage IA lung adenocarcinoma according to initial ALK status. Methods This is a retrospective cohort study including 309 patients with surgically resected stage IA lung adenocarcinoma from February 2010 to December 2013. Patients were screened for ALK rearrangement using immunohistochemistry. A positive ALK status was defined as an immunohistochemistry score of 2+ or more. Both disease-free survival (DFS) and the initial recurrence pattern were analyzed according to ALK status. Results Twenty-three (7.4%) patients had ALK-positive adenocarcinoma. During the median follow-up of 35.8 months, recurrence developed in 34 (11.0%) patients. The patients with ALK-positive tumor had significantly lower 5-year DFS rate (62.4%) compared to those with ALK-negative tumor (86.5%; P=0.038). The multivariable analysis showed that ALK rearrangement was associated with a higher risk of disease recurrence (adjusted hazard ratio =2.64; 95% confidence interval, 1.08-6.44). In addition, patient with ALK-positive tumor showed more frequent recurrence in regional lymph nodes compared with those with ALK-negative tumor (83.3% vs. 28.6%; P=0.031). Conclusions In patients with completely resected stage IA lung adenocarcinoma, ALK rearrangement was associated with unfavorable DFS and more frequent regional lymph node metastasis. Therefore, careful surveillance for recurrence should be performed in this subset of patients.

Lack of association between airflow limitation and recurrence of venous thromboembolism among cancer patients with pulmonary embolism

Background COPD is a well-known risk factor for venous thromboembolism (VTE) development. However, recent data showed that it was not associated with VTE recurrence risk, which excluded cancer patients. This study investigated the association of airflow limitation and VTE recurrence in cancer patients with pulmonary embolism (PE). Methods This is a retrospective cohort study of cancer patients with newly diagnosed PE at a university hospital. PE was confirmed using contrast-enhanced computed tomography scan. Airflow limitation was defined as pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.7 within 2 years of PE diagnosis. VTE recurrence was defined as a composite of recurrence as PE or deep vein thrombosis or both. Results Among 401 cancer patients with newly diagnosed PE, spirometry-based airflow limitation was observed in 126 (31.4%) patients. Half of the patients had lung cancer, which was more common in the group with airflow limitation (65.1% vs 42.9%, p < 0.001). Symptomatic PE was present in less than half (45.4%) of the cases, and 62.6% of patients were treated for PE. During the median follow-up period of 9.7 months, VTE recurred in 49 (12.2%) patients. Compared with patients without airflow limitation, those with airflow limitation did not have an increased risk of VTE recurrence in univariate or multivariate analyses (adjusted hazard ratio, 1.29 [95% CI 0.68, 2.45]). Conclusion The presence of airflow limitation did not increase the risk of VTE recurrence in cancer patients with PE. Prospective studies are needed to validate this finding.