Objectives: This study examined the association between various tobacco product use behaviors and metabolic syndrome (MetS) among Korean adults. Methods: Data from 15 359 adults aged ≥19 years who participated in the 2020–2022 Korea National Health and Nutrition Examination Survey were analyzed. Participants were classified as dual users, e-cigarettes (EC; nicotine-containing liquid-type)/ heated tobacco products (HTP) users, cigarette-only users, ex-smokers, or non-smokers. MetS was defined according to the NCEP ATP III criteria. Subgroup analyses were conducted by survey year and age group. Complex-sample cross-tabulation and logistic regression analyses were performed. Results: All types of tobacco product use were associated with an increased likelihood of MetS compared with non-smokers. This association was particularly evident among dual users (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.12 to 1.94) and cigarette-only users (OR, 1.19; 95% CI, 1.01 to 1.41). The highest risk was observed among adults aged 19–39 years and among dual users in 2020. Conclusions Dual use and cigarette smoking were associated with a higher likelihood of MetS, particularly among younger adults. Efforts are needed to reduce the misconception that EC/HTP products are less harmful alternatives and to strengthen education and prevention in order to prevent changes in tobacco use behavior from leading to new health risks.

Background and Objectives: Hypertrophic cardiomyopathy (HCM) increases the risk of sudden cardiac death. Despite international guidelines for sudden death prevention and implantable cardiac defibrillator (ICD) use, clinical practices vary. This study assessed the practices and opinions of Korean cardiologists on HCM management, focusing on ICD use and reimbursement policies. Methods: A structured electronic survey was distributed to members of the Korean Society of Cardiology, covering HCM management, ICD preferences, and reimbursement policies. Results: A total of 119 cardiologists participated, with most being arrhythmia specialists (56.3%) and university professors (81.5%). Cardiac magnetic resonance imaging and genetic testing were underutilized (30.3% and 11.8%, respectively). Beta-blocker-refractory premature ventricular complexes were primarily managed with continued medical therapy (77.3%). ICD preferences varied by physician specialty and patient age, with subcutaneous ICDs preferred in younger patients and dual-chamber ICDs in older patients. Nearly half of respondents believed ICD reimbursement criteria required revision. Conclusions Significant variability in HCM management exists among Korean cardiologists, influenced by restrictive reimbursement criteria rather than clinical guidelines. Updated reimbursement policies and improved access to advanced diagnostics are needed to align with international standards and optimize patient care.

This study investigated the effects of radioiodine (RAI) therapy on fertility-related hormones, particularly anti-Müllerian hormone (AMH), and menopause in women with differentiated thyroid cancer (DTC). Materials and Methods: We recruited 46 women with regular menstrual cycles who underwent total thyroidectomy for DTC. After excluding those who were menopausal before surgery, 35 patients in the RAI group and seven in the control group were analyzed. AMH levels were measured at baseline, 6 months, 9 months, and 1 year post-operation. Statistical analyses included Kruskal–Wallis tests and linear mixed model. Results: The Kruskal–Wallis test showed no significant difference in AMH changes between RAI doses (p=0.62). Age was significantly associated with AMH levels, with corresponding to a decrease of 0.18 ng/mL per year (p＜0.001).No significant difference in AMH levels was observed between the RAI and control groups after adjusting for age and baseline AMH (p=0.62). At 6 months after surgery or RAI, AMH declined in 57.1% (4/7), 60.0% (9/15), and 50.0% (9/18) in the control, 30 mCi, and 50 mCi groups, respectively. Among single RAI-treated patients with long-term follow-up, AMH levels recovered to baseline or higher in 50.0% (2/4), 0.0% (0/1), and 42.9% (9/19) in the control, 30 mCi, and 50 mCi groups, respectively. Conclusion: RAI therapy in patients with DTC showed no significant impact on AMH levels compared to controls. Larger studies with longer follow-ups are needed to assess its long-term effects on fertility.

Esophageal perforation can lead to serious complications, and rapid diagnosis and treatment significantly affect the prognosis. Endoscopic vacuum-assisted closure (EndoVAC) therapy is widely accepted as a safe, well-tolerated, effective, versatile and practical procedure for the management of esophageal perforation in selected patients. We report the successful use of EndoVAC therapy for management of an esophageal perforation secondary to foreign body removal. A 56-year-old man presented to the emergency department for evaluation of chest pain after swallowing the plastic shell of a pill. Emergency endoscopy revealed an esophageal wall laceration (approximately 3 cm) and microperforation. The esophageal laceration and microperforation were limited to the mid-esophagus. The patient underwent EndoVAC therapy, which was repeated every 3–4 days for a total of six sessions over a period of 21 days. We observed improvement in the esophageal injury with granulation tissue formation during the fifth session. Subsequent follow-up evaluation, including esophagography and chest computed tomography confirmed complete healing of the esophageal injury. Following resumption of diet, the patienton a was discharged without any complications.

Background: We explored the utility of a small multi-gene DNA panel for assessing molecular profiles of thyroid nodules and influencing clinical decisions by comparing outcomes between tested and untested nodules. Methods: Between April 2022 and May 2023, we prospectively performed fine-needle aspiration (FNA) with gene testing via DNA panel of 11 genes (BRAF, RAS [NRAS, HRAS, KRAS], EZH1, DICER1, EIF1AX, PTEN, TP53, PIK3CA, TERT promoter) in 278 consecutive nodules (panel group). Propensity score-matching (1:1) was performed with 475 nodules that consecutively underwent FNA without gene testing between January 2021 and December 2021 (control group). Results: In the panel group, positive call rate for mutations was 41.7% (BRAF 16.2%, RAS 12.6%, others 11.5%, double mutation 1.4%) for all nodules, and 40.0% (BRAF 4.3%, RAS 19.1%, others 15.7%, double mutation 0.9%) for indeterminate nodules. Benign call rate was 69.8% for all nodules, and 75.7% for indeterminate nodules. In four nodules, additional TP53 (in addition to BRAF or EZH1) or PIK3CA (in addition to BRAF or TERT) mutations were co-detected. Sensitivity, specificity, positive predictive value, and negative predictive value were 80.0%, 53.3%, 88.1%, 38.1% for all nodules, and 78.6%, 45.5%, 64.7%, 62.5% for indeterminate nodules, respectively. Panel group exhibited lower surgical resection rates than the control group for all nodules (27.0% vs. 52.5%, P<0.001), and indeterminate nodules (23.5% vs. 68.2%, P<0.001). Malignancy risk was significantly different between the panel and control groups (81.5% vs. 63.9%, P=0.008) for all nodules. Conclusion Our panel aids in managing thyroid nodules by providing information on malignancy risk based on mutations, potentially reducing unnecessary surgery in benign nodules or patients with less aggressive malignancies.

Background: Papillary thyroid carcinoma (PTC) can be classified into two distinct molecular subtypes, BRAF-like (BL) and RASlike (RL). However, the molecular characteristics of each subtype according to clinicopathological factors have not yet been determined. We aimed to investigate the gene signatures and tumor microenvironment according to clinicopathological factors, and to identify the mechanism of progression in BL-PTCs and RL-PTCs. Methods: We analyzed RNA sequencing data and corresponding clinicopathological information of 503 patients with PTC from The Cancer Genome Atlas database. We performed differentially expressed gene (DEG), Gene Ontology, and molecular pathway enrichment analyses according to clinicopathological factors in each molecular subtype. EcoTyper and CIBERSORTx were used to deconvolve the tumor cell types and their surrounding microenvironment. Results: Even for the same clinicopathological factors, overlapping DEGs between the two molecular subtypes were uncommon, indicating that BL-PTCs and RL-PTCs have different progression mechanisms. Genes related to the extracellular matrix were commonly upregulated in BL-PTCs with aggressive clinicopathological factors, such as old age (≥55 years), presence of extrathyroidal extension, lymph node metastasis, advanced tumor-node-metastasis (TNM) stage, and high metastasis-age-completeness of resection- invasion-size (MACIS) scores (≥6). Furthermore, in the deconvolution analysis of tumor microenvironment, cancer-associated fibroblasts were significantly enriched. In contrast, in RL-PTCs, downregulation of immune response and immunoglobulin-related genes was significantly associated with aggressive characteristics, even after adjusting for thyroiditis status. Conclusion The molecular phenotypes of cancer progression differed between BL-PTC and RL-PTC. In particular, extracellular matrix and cancer-associated fibroblasts, which constitute the tumor microenvironment, would play an important role in the progression of BL-PTC that accounts for the majority of advanced PTCs.

Purpose: The isocitrate dehydrogenase (IDH) family plays an essential role in metabolism and energy production. The relative expression levels of IDH isoforms (IDH1, IDH2, and IDH3) have prognostic significance in several malignancies, including breast carcinoma. However, the IDH isozyme expression levels in different cancer stages and types have not been determined in breast carcinoma tissues. Methods: We analyzed the messenger RNA (mRNA) and protein levels of IDH (IDH1, IDH2, and IDH3A) and α-ketoglutarate (α-KG) in 59 breast carcinoma tissues. Results: The mRNA level of IDH2 was significantly increased at stages 2 and 3 in triple-negative and (ER-/PR-/HER+) breast cancers. However, the elevated α-KG level was only observed in stages 2 and 3, with no differences in the various breast carcinoma types. Western blotting analysis showed that IDH2 protein expression increased in the patient tissues and cell lines. An in vitro study showed IDH2 downregulation in the triple-negative breast cancer cell line MDA-MB-231 that inhibited cell proliferation and migration and induced cell cycle arrest in the G0/G1 phase. Conclusion These findings suggest that different from IDH1 and IDH3, IDH2 is more highly expressed in stages 2 and 3 breast cancer tissues, especially in triple-negative breast cancer. IDH2 potentially serves as a target to detect unknown mechanisms in breast cancer.

Purpose: Occupational exposure to pesticides is thought to be associated with lung cancer, but studies have yielded conflicting results. We performed a propensity score (PS) based analyses to evaluate the relationship between occupational exposure to pesticides and lung cancer risk in the Korea National Cancer Center community-based cohort study (KNCCCS). Materials and Methods: During the follow-up period, 123 incidental lung cancer cases were identified, of the 7,471 subjects in the final statistical analysis. Information about occupational exposure to pesticides and other factors was collected at enrollment (2003-2010). Cox proportional hazards regression analyses were conducted. Four PS-based approaches (i.e., matching, stratification, inverse probability-of-treatment weighting, and the use of the PS as a covariate) were adopted, and the results were compared. PS was obtained from the logistic regression model. Absolute standardized differences according to occupational exposure to pesticides were provided to evaluate the balance in baseline characteristics. Results: In the Cox proportional hazards regression model, the hazard ratio (HR) for lung cancer according to occupational exposure to pesticides was 1.82 (95% confidence interval [CI], 1.11 to 2.98). With all the propensity score matching (PSM) methods, the HRs for lung cancer based on exposure to pesticides ranged from 1.65 (95% CI, 1.04 to 2.64) (continuous term with PSM) to 2.84 (95% CI, 1.81 to 4.46) (stratification by 5 strata of the PS). The results varied slightly based on the method used, but the direction and statistical significance remained the same. Conclusion Our results strengthen the evidence for an association between occupational exposure to pesticides and the risk of lung cancer.

We aimed to review the current data composition of the Korean Tuberculosis and Post-Tuberculosis Cohort, which was constructed by linking the Korean Tuberculosis Surveillance System (KNTSS; established and operated by the Korean Disease Control and Prevention Agency since 2000) and the National Health Information Database (NHID; established by the National Health Insurance Service in 2012). The following data were linked: KNTSS data pertaining to patients diagnosed with tuberculosis between 2011 and 2018, NHID data of patients with a history of tuberculosis and related diseases between 2006 and 2018, and data (obtained from the Statistics Korea database) on causes of death. Data from 300 117 tuberculosis patients (177 206 men and 122 911 women) were linked. The rate of treatment success for new cases was highest in 2015 (86.7%), with a gradual decrease thereafter. The treatment success rate for previously treated cases showed an increasing trend until 2014 (79.0%) and decreased thereafter. In total, 53 906 deaths were confirmed among tuberculosis patients included in the cohort. The Korean Tuberculosis and Post-Tuberculosis Cohort can be used to analyze different measurement variables in an integrated manner depending on the data source. Therefore, these cohort data can be used in future epidemiological studies and research on policy-effect analysis, treatment outcome analysis, and health-related behaviors such as treatment discontinuation.

Purpose: Tumor size and lymph node metastasis are important factors that contribute to the progression of breast cancer. We aimed to analyze the relationship between tumor size and lymph node metastasis molecular subtype and examine the effects of nodal metastasis on overall survival (OS). Methods: We retrospectively reviewed the data of 16,552 patients who underwent breast surgery in Samsung Medical Center between 2000 and 2015. Information on tumor size (largest diameter of the invasive component), number of positive lymph nodes, and molecular subtype were obtained. We constructed a linear regression model to evaluate the relationship between tumor size and lymph node metastasis. To determine the effect of nodal metastasis on OS, we performed a Cox proportional regression analysis with Np/T (number of metastatic lymph nodes [n]/tumor size [cm]). Results: This study included 12,007 patients with a median follow-up of 62 months. The linear regression coefficients were 1.043 for luminal A, 1.024 for luminal B, 0.656 for HER2, and 0.435 for triple-negative breast cancer (TNBC) subtypes. No significant difference was observed in the coefficients between the luminal A and B subtypes (p = 0.797), while all other coefficients showed significant difference. After adjusting for other risk factors, the hazard ratio (HR) of Np/T for each subtype was significant for OS: luminal A (HR, 1.134; 95% confidence interval [CI], 1.097–1.171; p < 0.001), luminal B (HR, 1.049; 95% CI, 1.013–1.086;p = 0.007), HER2 (HR, 1.069; 95% CI, 1.014–1.126; p = 0.013), and TNBC (HR, 1.038; 95% CI, 1.01–1.067; p = 0.008). Conclusion The incidence of lymph node metastasis differed according to molecular subtype. Luminal types have higher incidence of nodal metastasis than HER2 and TNBC. The HR of Np/T was highest in luminal A subtypes and lowest in TNBC subtypes.