Objectives: Estimating the number of deaths caused by smoking is crucial for developing and evaluating tobacco control and smoking cessation policies. This study aimed to determine smoking-attributable mortality (SAM) in Korea in 2020. Methods: Four large-scale cohorts from Korea were analyzed. A Cox proportional-hazards model was used to determine the hazard ratios (HRs) of smoking-related death. By conducting a meta-analysis of these HRs, the pooled HRs of smoking-related death for 41 diseases were estimated. Population-attributable fractions (PAFs) were calculated based on the smoking prevalence for 1995 in conjunction with the pooled HRs. Subsequently, SAM was derived using the PAF and the number of deaths recorded for each disease in 2020. Results: The pooled HR for all-cause mortality attributable to smoking was 1.73 for current men smokers (95% confidence interval [CI], 1.53 to 1.95) and 1.63 for current women smokers (95% CI, 1.37 to 1.94). Smoking accounted for 33.2% of all-cause deaths in men and 4.6% in women. Additionally, it was a factor in 71.8% of men lung cancer deaths and 11.9% of women lung cancer deaths. In 2020, smoking was responsible for 53 930 men deaths and 6283 women deaths, totaling 60 213 deaths. Conclusions Cigarette smoking was responsible for a significant number of deaths in Korea in 2020. Monitoring the impact and societal burden of smoking is essential for effective tobacco control and harm prevention policies.

Objectives: In March 2023, an alternative school in the Republic of Korea reported 12 cases of shigellosis. This study aims to analyze the epidemiological characteristics in order to determine the cause of the cluster outbreak of shigellosis and to develop prevention strategies. Methods: This study focused on 12 patients with confirmed Shigella infection and investigated their demographics, clinical features, epidemiology, diagnostics, and antimicrobial susceptibility. Following the identification of Shigella, we conducted follow-up rectal smear cultures to manage patients, implementing isolation and control measures. Results: This study investigated the emergence of multidrug-resistant Shigella following missionary activities in Cambodia, documenting a cluster infection within an alternative school in Daejeon, the Republic of Korea. The outbreak affected 56 participants, resulting in the confirmation of 12 cases. The incidence rates varied by gender and occupation, with higher rates among males and teachers. All 12 cases demonstrated multidrug resistance. Challenges included delayed pathogen confirmation and suboptimal adherence to isolation criteria. The incident prompted revisions in the criteria for isolation release, focusing on symptom resolution. The study underscores the necessity for strengthened surveillance, educational initiatives focusing on prevention in endemic areas, and improved oversight of unlicensed educational establishments. Conclusion Successful response strategies included swift situation assessment, collaborative efforts, effective infection control measures, and modified criteria for isolation release. Continued surveillance of multidrug-resistant strains is recommended, especially in regions with a high prevalence.

Background: Radiation exposure is a well-known risk factor for papillary thyroid cancer (PTC). South Korea has 24 nuclear reactors in operation; however, no molecular biological analysis has been performed on patients with PTC living near nuclear power plants. Methods: We retrospectively included patients with PTC (n=512) divided into three groups according to their place of residence at the time of operation: inland areas (n=300), coastal areas far from nuclear power plants (n=134), and nuclear power plant areas (n=78). After propensity score matching (1:1:1) by age, sex, and surgical procedure, the frequency of representative driver mutations and gene expression profiles were compared (n=50 per group). Epithelial-mesenchymal transition (EMT), BRAF, thyroid differentiation, and radiation scores were calculated and compared. Results: No significant difference was observed in clinicopathological characteristics, including radiation exposure history and the frequency of incidentally discovered thyroid cancer, among the three groups. BRAFV600E mutation was most frequently detected in the groups, with no difference among the three groups. Furthermore, gene expression profiles showed no statistically significant difference. EMT and BRAF scores were higher in our cohort than in cohorts from Chernobyl tissue bank and The Cancer Genome Atlas Thyroid Cancer; however, there was no difference according to the place of residence. Radiation scores were highest in the Chernobyl tissue bank but exhibited no difference according to the place of residence. Conclusion Differences in clinicopathological characteristics, frequency of representative driver mutations, and gene expression profiles were not observed according to patients’ region of residence in South Korea.

Background: In 2015, tobacco prices significantly increased in Korea as part of the government’s smoking cessation policy. This study examined the changes in the stages of smoking cessation among Korean male smokers before and after the implementation of the tobacco price policy, and identified the predictors of such changes. Methods: The study population comprised 3,533 male current smokers (age ≥19 years) who participated in the Korea National Health and Nutrition Survey in 2012, 2013, 2015, and 2016. Current smokers were defined as persons who had smoked ≥100 cigarettes during their lifetime and are continuing to smoke. In accordance with the transtheoretical model, smokers were classified into the precontemplation stage (no plan to quit), contemplation stage, and preparation stage (planning to quit within 6 months). We examined the changes in the smoking cessation stages before and after the implementation of the policy. Multivariate logistic regression analysis was conducted to identify factors related to the likelihood of continuing smoking, after adjustments for potential confounders. Results: Immediately after the policy implementation, the percentage of smokers in the precontemplation stage decreased from 65.6% to 60.8% (P=0.014). However, this effect was temporary. Significant risk factors for remaining in the precontemplation stage were older age (odds ratio [OR], 1.010; 95% confidence interval [CI], 1.002–1.018; P=0.004), being in the lowest income quartile (OR, 1.226; 95% CI, 1.001–1.502; P=0.049), and manual worker or unemployed status (OR, 1.256; 95% CI, 1.036–1523; P=0.020). Conclusion Increasing tobacco prices only temporarily change the stage of smoking cessation among Korean male smokers.

Background: Cancer survivors experience decreased physical function and reduced muscle strength, which leads to lower quality of life (QOL). The hand grip strength (HGS) can be a predictor of poor health-related QOL as a parameter of sarcopenia. The purpose of this study was to investigate the relationship between low HGS and QOL in cancer survivors and healthy controls. Methods: We analyzed 392 cancer survivors and 1,176 healthy controls from the Korea National Health and Nutrition Examination Survey, 2014–2017. We defined low HGS as 2 standard deviation values for healthy young Korean adults from a previous study. QOL was evaluated using the European Quality of Life Scale-Five Dimensions. A complex sample logistic regression model was used to assess the relationship between each dimension of low HGS and QOL. Results: The odds ratios (ORs) for decreased QOL were significantly higher in male cancer survivors with low HGS on self-care (OR, 8.51; 95% confidence interval [CI], 1.69–42.83) and usual activities (OR, 6.63; 95% CI, 1.22–36.03). The ORs for problems in mobility (OR, 5.87; 95% CI, 2.04–16.91), usual activities (OR, 14.46; 95% CI, 3.84–54.44), pain/discomfort (OR, 4.90; 95% CI, 2.00–12.01), and anxiety/depression (OR, 6.43; 95% CI, 2.16–19.12) were significantly high in female cancer survivors with low HGS. However, healthy controls showed no significant relationship between low HGS and QOL. Conclusion For cancer survivors, low HGS was associated with poor QOL in some domains. Strategies to increase muscle strength must be considered to improve the QOL of cancer survivors.

Background: In 2015, tobacco prices significantly increased in Korea as part of the government’s smoking cessation policy. This study examined the changes in the stages of smoking cessation among Korean male smokers before and after the implementation of the tobacco price policy, and identified the predictors of such changes. Methods: The study population comprised 3,533 male current smokers (age ≥19 years) who participated in the Korea National Health and Nutrition Survey in 2012, 2013, 2015, and 2016. Current smokers were defined as persons who had smoked ≥100 cigarettes during their lifetime and are continuing to smoke. In accordance with the transtheoretical model, smokers were classified into the precontemplation stage (no plan to quit), contemplation stage, and preparation stage (planning to quit within 6 months). We examined the changes in the smoking cessation stages before and after the implementation of the policy. Multivariate logistic regression analysis was conducted to identify factors related to the likelihood of continuing smoking, after adjustments for potential confounders. Results: Immediately after the policy implementation, the percentage of smokers in the precontemplation stage decreased from 65.6% to 60.8% (P=0.014). However, this effect was temporary. Significant risk factors for remaining in the precontemplation stage were older age (odds ratio [OR], 1.010; 95% confidence interval [CI], 1.002–1.018; P=0.004), being in the lowest income quartile (OR, 1.226; 95% CI, 1.001–1.502; P=0.049), and manual worker or unemployed status (OR, 1.256; 95% CI, 1.036–1523; P=0.020). Conclusion Increasing tobacco prices only temporarily change the stage of smoking cessation among Korean male smokers.

Background: Cancer survivors experience decreased physical function and reduced muscle strength, which leads to lower quality of life (QOL). The hand grip strength (HGS) can be a predictor of poor health-related QOL as a parameter of sarcopenia. The purpose of this study was to investigate the relationship between low HGS and QOL in cancer survivors and healthy controls. Methods: We analyzed 392 cancer survivors and 1,176 healthy controls from the Korea National Health and Nutrition Examination Survey, 2014–2017. We defined low HGS as 2 standard deviation values for healthy young Korean adults from a previous study. QOL was evaluated using the European Quality of Life Scale-Five Dimensions. A complex sample logistic regression model was used to assess the relationship between each dimension of low HGS and QOL. Results: The odds ratios (ORs) for decreased QOL were significantly higher in male cancer survivors with low HGS on self-care (OR, 8.51; 95% confidence interval [CI], 1.69–42.83) and usual activities (OR, 6.63; 95% CI, 1.22–36.03). The ORs for problems in mobility (OR, 5.87; 95% CI, 2.04–16.91), usual activities (OR, 14.46; 95% CI, 3.84–54.44), pain/discomfort (OR, 4.90; 95% CI, 2.00–12.01), and anxiety/depression (OR, 6.43; 95% CI, 2.16–19.12) were significantly high in female cancer survivors with low HGS. However, healthy controls showed no significant relationship between low HGS and QOL. Conclusion For cancer survivors, low HGS was associated with poor QOL in some domains. Strategies to increase muscle strength must be considered to improve the QOL of cancer survivors.

Background and Objectives: Although thyroid hormones affect human cancer progression, the regulatory mechanism of thyroid hormone receptors in carcinogenesis has not been elucidated. This study aimed to evaluate the expression pattern of the thyroid hormone receptor (TR) and its corepressors, and to investigate the clinical and biological functions of TR. Materials and Methods: Transcriptomic and clinical data for thyroid cancer were downloaded from The Cancer Genome Atlas. Paraffin-embedded tissue sections from patients who underwent thyroidectomy were used for immunohistochemistry. BCPAP cells were treated with T3 to investigate the thyroid hormone target genes. Thyroid hormone receptor alpha (THRA) and Thyroid hormone receptor beta (THRB) were knocked down by transient siRNA transfection. Results: THRA and THRB expression was lower in thyroid cancer tissues than in normal tissues. However, strong focal staining of TRβ was observed in the invasive front. High THRB expression was associated with high Silencing Mediator for Retinoid or Thyroid hormone receptor (SMRT) expression, older age, a high MACIS (distant Metastasis, patient Age, Completeness of resection, local Invasion, and tumor Size) score, more aggressive histological subtypes, more frequent extra-thyroidal extension, and advanced TNM stage. THRB expression was positively correlated with Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A), L1 Cell Adhesion Molecule (L1CAM), and Lysyl Oxidase (LOX) expression. Thyroid hormone-induced HIF1A, L1CAM, and LOX upregulation was abolished by siTHRB but not siTHRA in BCPAP cells. High SMRT and high THRB groups (SMRT/THRB) presented more aggressive clinical features and showed an upregulation of HIF1A, L1CAM, and LOX, as well as of epithelial-mesenchymal transition (EMT)-related genes, causing changes in the tumor microenvironment. Conclusion Cooperative subtype switching from NCOR1/THRA to SMRT/THRB was thus related to aggressive clinical and molecular features, possibly related to EMT and EMT-related tumor microenvironment.

Background: Despite the autologous serum skin test (ASST)and autologous plasma skin test (APST) is widely used test accessingwhether a patient with chronic spontaneous urticaria(CSU) has autoreactivity or not, the clinician often encounterdifficulty making correlation between the test result and clinicalimplications. Objective: This study was aimed to findany clinical and laboratory findings related to the ASST andAPST response. Agreement and correlation between the twotests was also analyzed. Methods: A retrospective study wasconducted on 300 CSU patients who underwent ASST, APST.The subjects were divided into four groups according to theskin test result. Also, the degree of serum and plasma responsewas recorded. Results: Both ASST and APST positivegroup had shorter duration of the disease, higher incidenceof at least one episode of angioedema than negative group.There were no significant differences in the positivity for autoantibodiesincluding antinuclear, ds-DNA, and thyroid-relatedbetween the two groups. The predicted positive rate ofASST and APST according to age showed bimodal peak and decreasing pattern according to disease duration. Predictedpositivity of both tests declined with increase in total immunoglobulineE (IgE) level. In the correlation study, the twotests showed high correlation coefficients. Conclusion ASSTand APST positivity may be related to disease duration andseverity of CSU. The two tests showed a generally consistentresult. Autoreactivity may be gradually lost as disease continues.We suggest the autoreactivity in CSU could arise independentlyfrom IgE mediated immune process.

Purpose: The purpose of this study was to determine the rate and outcomes of pregnancies subsequentto breast cancer in Korea, and the effect of such pregnancies on the prognosis ofwomen who survived breast cancer and subsequently conceived. Materials and Methods: We followed a total of 31,761 Korean women 45 years of age or younger who were treatedfor primary breast cancer from 2002 to 2010. We also included follow-up surveys that wereconducted through December 2011. We identified recurrence and mortality from breastcancer using data linked to the Korea National Health Insurance database. We used propensityscore matching of the study cohort to analyze the risks of recurrence and mortality frombreast cancer depending on pregnancy. Results: Within our sample, 992 women (3.1%) became pregnant after receiving treatment for breastcancer. Of those, 622 (67.5%) successfully delivered; the remaining 370 (32.5%) failed todeliver. After propensity score matching, we found that the women who became pregnantafter breast cancer did not have a different risk of recurrence (hazard ratio [HR], 0.503;95% confidence interval [CI], 0.434 to 0.584) and death (HR, 0.520; 95% CI, 0.397 to0.681), compared with those who did not conceive after breast cancer treatment. Conclusion Our study is the first to report outcomes for Korean women who survived breast cancer andsubsequently conceived. Women who survived breast cancer and subsequently becamepregnant did not show a poorer survival outcome, compared with those who did not becomepregnant.