• Korean Journal of Radiology
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• v.22 no.3
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• pp.425-434
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• 2021

Objective: To investigate the potential value of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT in predicting the survival of patients with primary tracheal malignant tumors. Materials and Methods: An analysis of FDG PET/CT findings in 37 primary tracheal malignant tumor patients with a median follow-up period of 43.2 months (range, 10.8-143.2 months) was performed. Cox proportional hazards regression analyses were used to assess the associations between quantitative ¹⁸F-FDG PET/CT parameters, other clinic-pathological factors, and overall survival (OS). A risk prognosis model was established according to the independent prognostic factors identified on multivariate analysis. A survival curve determined by the Kaplan-Meier method was used to assess whether the prognosis prediction model could effectively stratify patients with different risks factors. Results: The median survival time of the 37 patients with tracheal tumors was 38.0 months, with a 95% confidence interval of 10.8 to 65.2 months. The 3-year, 5-year and 10-year survival rate were 54.1%, 43.2%, and 16.2%, respectively. The metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value, age, pathological type, extension categories, and lymph node stage were included in multivariate analyses. Multivariate analysis showed MTV (p = 0.011), TLG (p = 0.020), pathological type (p = 0.037), and extension categories (p = 0.038) were independent prognostic factors for OS. Additionally, assessment of the survival curve using the Kaplan-Meier method showed that our prognosis prediction model can effectively stratify patients with different risks factors (p < 0.001). Conclusion: This study shows that ¹⁸F-FDG PET/CT can predict the survival of patients with primary tracheal malignant tumors. Patients with an MTV > 5.19, a TLG > 16.94 on PET/CT scans, squamous cell carcinoma, and non-E1 were more likely to have a reduced OS.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.48.1-48.13
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• 2023

Background: This study was conducted to identify the success rate for smoking cessation over time after participation in a therapeutic smoking cessation camp, and to identify how participant characteristics, including a supportive workplace environment for smoking cessation (SWESC), affect the success rate for smoking cessation. Methods: In all, 296 participants at smoking cessation camps in Ulsan between 2015 and 2020 were investigated. The success rates of smoking cessation after weeks 4, 6, 12, and 24 at camp were investigated. The participants were grouped as workers with an SWESC, and workers without an SWESC, and variables (age, education, household income, marital status, drinking, exercise, body mass index, morbidity, job, number of counseling sessions, cigarettes smoked per day and smoking initiation age) were investigated. Multiple logistic regression analysis was conducted at each time point. In addition, Cox regression analysis was performed to evaluate the variables affecting the success rate for smoking cessation over time. Results: The smoking cessation success rate of workers with an SWESC at week 24 (90.7%) was higher than that for workers without an SWESC (60.5%). Multiple logistic regression was performed to determine the relationship between each variable and the success rates for smoking cessation at week 6, 12, and 24. SWESC was confirmed as significant (p < 0.05) variables for increased success rate for smoking cessation at all 3 time points. After adjusting for all variables, the Cox proportional hazards survival analysis showed a hazard ratio of 6.17 for SWESC (p < 0.001,; 95% confidence interval: 3.08-12.38). Conclusions: At a professional treatment smoking cessation camp, participants with an SWESC showed a significantly higher success rate for smoking cessation. Supportive workplace environment for workers' health is expected to be an important factor for smoking cessation projects as well as other health promotion projects at workplace.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.41.1-41.11
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• 2023

Background: Shift work has been reported to have several harmful effects on the human body. However, a small number of studies have evaluated the association between shift work and adverse effects on the thyroid. In our longitudinal study, we examined the causal association between shift work and the risk of hypothyroidism. Methods: A Kangbuk Samsung Cohort Study was conducted on 112,648 men without thyroid disease at baseline who were followed up at least once between 2012 and 2019. Shift work status and shift schedule types were categorized using standardized questionnaires. Hypothyroidism was defined using the reference ranges of serum thyroid-stimulating hormones and free thyroxine levels. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident hypothyroidism were estimated using Cox proportional hazards regression analyses with the daytime work group as the reference. Results: During the 501,237 person-years of follow-up, there were 6,306 incident cases of hypothyroidism (incidence density, 1.26 per 100 person-years). The multivariable-adjusted HR of incident hypothyroidism for the shift work total group that included all shifts compared with the daytime work group was 1.27 (95% CI: 1.15-1.40). For the fixed evening, fixed night, rotating shift, and other shift workers, the multivariable-adjusted HRs (95% CI) were 1.11 (0.76-1.61), 2.18 (1.20-3.93), 1.39 (1.23-1.56), and 1.00 (0.82-1.22), respectively. In subgroup analyses by age, the association between shift work and hypothyroidism was more pronounced in younger participants (< 40 years; HR: 1.31; 95% CI: 1.16-1.47). Conclusions: Our large-scale cohort study showed an association between shift work and the incidence of hypothyroidism, especially in younger workers with night shifts.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.489-496
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• 2003

To clarify the prognostic implication of the location and number of the metastatic mediastinal nodes in resected stage IIIA N2 non-small cell lung cancer. Material and Method: One hundred and seventy-four patients with resected non-small cell lung cancer who eventually proved to have pathologic stage IIIA N2 disease were studied. Patients who received preoperative induction therapy, non-curative operation or defined as operative mortality were excluded from this study. Result: In upper lobe tumors, there was no difference in 5-year survival according to the involvement of lower mediastinal nodes (32.3% vs 25.6%, p＝0.86). In lower lobe tumors, no difference was found in 5-year survival according to the involvement of upper mediastinal nodes (25.1% vs 14.1%, p＝0.33). There was no significant difference in 5-year survival between patients with or without metastatic subcarinal node (20.9% vs 25.6%, p＝0.364). In terms of the number of metastatic mediastinal nodes, 5-year survival was better in single station group (26.3%) than multiple station group (18.3%) (p＝0.048). In multiple station N2 group, the patients who received postoperative chemotherapy and radiation therapy had better 5-year survival (34.2%) (p＝0.01). Cox's proportional hazards model revealed that the age $\geq$60 (O.R: 1.682, p＝.006), multiple station N2 (O.R: 1.503. p＝0.021), pneumonectomy (O.R: 1.562, p＝0.018), postoperative chemotherapy and radiation therapy (O.R: 0.625, p＝0.012) were the factors affecting the postoperative survival. Conclusion: Multiple station N2 disease was the important prognostic factor for postoperative survival in resected stage IIIA N2 non-small cell lung cancer. Postoperative chemotherapy and radiotherapy were thought to improve the survival in case of multiple station N2 disease.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.61-66
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• 2012

Purpose: This study was to compare the cumulative survival rate (CSR) of Br${\aa}$nemark machined surface implants and TiUnite$^{TM}$ imlants and to analyze association between risk factors and the CSR of the implants. Materials and methods: A retrospective study design was used to collect long-term follow-up clinical data from dental records of 156 patients treated with 541 Br${\aa}$nemark machined and TiUnite$^{TM}$ implants at Korea University Guro hospital in South Korea from 1993 through 2008. Machined implant and TiUnite$^{TM}$ implant were compared by CSR. Exposure variables such as gender, systemic disease, location, implant length, diameter, prosthesis type, opposing occlusion type, date of implant placement, type of edentulous space, abutment type, existence of splinting with natural teeth, and existence of cantilever were collected. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR (${\alpha}$=.05). Results: Patient ages ranged from 16 to 75 years old (mean age, 51 years old). Implants were more frequently placed in men than women (94 men versus 63 women). Since 1993, 264 Br${\aa}$nemark machined implants were inserted in 79 patients and since 2001, 277 TiUnite$^{TM}$ implants were inserted in 77 patients. A total survival rate of 86.07% was observed in Br${\aa}$nemark and Nobel Biocare TiUnite$^{TM}$ during 15 years. A survival rate of machined implant during 15 years was 82.89% and that of TiUnite$^{TM}$ implant during 5 years was 98.74%. The implant CSR revealed lower rates association with several risk factors such as, systemic disease, other accompanied surgery, implant location, and Kennedy classification. Conclusion: Clinical performance of Br${\aa}$nemark machined and TiUnite$^{TM}$ implant demonstrated a high level of predictability. In this study, TiUnite$^{TM}$ implant was more successful than machined implant. The implant CSR was associated with several risk factors.

• Journal of Preventive Medicine and Public Health
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• v.15 no.1
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• pp.145-151
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• 1982

Breslau's report on the two stillbirths induced by illuminating gas poisoning made many investigators explore the hazards. of carbon monoxide(CO) poisoning to pregnancy. The pregnant woman, her fetus, and the newborn infant have been identified to be particularly vulnerable to CO even in low concentration. Several factors, such as placental barrier, membrane resistance of maternal and fetal red blood cells etc., were considered to be related to the delayed elimination of CO from fetus. Slower elimination of CO from fetus than from mother was confirmed in several in vivo studies. But there are few studies which have confirmed the difference of carboxyhemoglobin (HbCO) dissociation in adult and fetal bloods. Author investigated the effects of hemoglobin itself on the elimination of CO from mother and fetus. By observing the difference of CO dissociation from adult and fetal hemoglobin at the various partial pressures of oxygen, the author tries to suggest the base of the proper treatment measure for the CO poisoning of pregnant woman and newborn infant. The results were as follows: 1. The total hemoglobin amounts of adults and fetal bloods were $16.1{\pm}0.50gm%\;and\;15.7{\pm}0.32gm%$, respectively. The fetal hemoglobin proportions in adult and fetal bloods were $1.2{\pm}0.15%\;and\;72.7{\pm}3.01%$, respectively. 2. Adult and fetal bloods saturated by CO to 100% HbCO were exposed to ambient air$(21%\;O_2),\;100%\;O_2\;and\;3\;ATAO_2$. After 30 minutes exposure, the HbCO saturations of adult blood were 96.7%, 70.9%, and 52.8%, respectively, and those of fetal blood were 98.5%, 76.1%, and 62.2%, respectively. HbCO dissociation was proportional to the partial pressure of oxygen and the most marked dissociation was shown under 3 ATA $O_2$, HbCO dissociation of fetal blood was slower than that of adult blood in all conditions. According to the above results, it is possible that CO poisoning make more serious damage to the fetus and newborn infant than to the adult due to the delayed dissociation of HbCO. Thus in the treatment of CO poisoning of pregnant woman and newborn infant, hyperbaric oxygen therapy seems to be the most eflective treatment measure, but the duration of hyperbaric oxygenation should be lengthened accordingly.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.281-287
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• 2005

Purpose: This study was conducted to evaluate the effectiveness and the role of post-operative adjuvant chemoradiation therapy in a stage-II (UICC, 1997) primary gastric cancer. Materials and Methods: From September 1994 to December 2004, 954 stage-II gastric-cancer patients were seen, and all of them underwent a curative resection with extensive (D2) lymph-node dissection. The chemotherapy consisted of fluorouracil $(400mg/m^2)$ plus leucovorin $(20mg/m^2)$ for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks with fluorourcil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two five-day cycles of chemotherapy were given four weeks after the completion of radiotherapy. The Kaplan-Meier method was used to estimate the survival rates. To assess the importance of potential prognostic factors, we performed univariate and multivariate analyses using a log-rank test and Cox's proportional hazards regression model. A P value <0.05 was considered significant. Results: Univariate analysis revealed that age, tumor size, gross type, surgical method, and postoperative adjuvant therapy had statistical significance. Among these factors, age, surgical method, tumor size, surgical method, and postoperative adjuvant therapy were found to be independent prognostic factors by using a multivariate analysis. The postoperative adjuvant chemotherapy group and the chemoradiation therapy group had survival benefit compared to the surgery-only group. However the chemoradiation therapy group had no significant survival benefit compared to the chemotherapy group. Conclusion: The postoperative adjuvant therapy in stage-II gastric-cancer patients had significant benefit. Therefore, postoperative adjuvant chemoradiation therapy has an acceptable effect. A large-scale, randomized study is needed to evaluate the effectiveness and the role of postoperative radiation therapy.

• Korean Journal of Social Welfare
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• v.68 no.2
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• pp.107-130
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• 2016

This study is aimed at the exploratory research on the influence of the obligation of extension of the retirement age on the baby boom generation. The basic question of this study is about which of the baby boom generation can get how much benefit according as the extension of the retirement age becomes compulsory. The extension of the retirement age is the system that can be applied to regular full-time workers. Accordingly, this study is intending to analyze the characteristics of the workers having a high likelihood for benefits from extension of the retirement age by tracing the economic activity state and labor history of the baby boomers. For this purpose, this study looked into the change of the economic activity state by age cohort of the male baby boomers based on the data for the Korea Labor Panel's 4th(2001) & 17th(2014)year. Using Survival analysis, this study also analyzed who will continue to remain as a regular full-time wage earner. As the result of the analysis, it was found that the more the cohort ages of baby boomers increased, the smaller the probability of remaining as a regular full-time wage earner, and the group who can get benefits from extension of the retirement age was predicted to account for only 11.4% level among the baby boomers. In addition, the result showed that there was a high likelihood of getting more benefits from extension of the retirement age when the baby boomers worked for the government-invested institution, corporate bodies, and government organizations rather than working for private enterprises. Thus, it can be safely said that there might appear a generational conflict due to extension of the retirement age in that such jobs coincide with the ones favored by the rising generation.

• Journal of Chest Surgery
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• v.40 no.2 s.271
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• pp.109-113
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• 2007

Background: In non-small cell lung cancer (NSCLC), malignant pleural effusion is a frequently observed com-plication, and is an important negative prognostic factor. Although many studies concerned to diagnosis and treatment of malignant pleural effusion have been performed, prognostic factors of malignant pleural effusion have rarely been investigated. This study was performed to determine the prognostic factors of malignant pleural effusion n non-small cell lung cancer. Material and Method: We evaluated 33 NSCLC patients with malignant effusion treated between January 2002 and December 2003. We analyzed possible factors: gender, age, TNM Stage, fluid analysis (pH, CEA, LDH, glucose, albumin) and treatment modality. Median survival time of each factor was calculated by Kaplan-Meier method and difference of median survival time between groups of factor compared by log-rank test. The Cox proportional hazards regression model was used to confirm the significance of prognostic factor. Results: Of the 33 patients, 23 (69.7%) patients were adenocarcinoma. The median interval of the diagnosis of lung cancer and malignant effusion was 7.3 months ($25^{th}{\sim}75^{th}:\;3.9{\sim}11.8$), and the median survival time was 3.6 months (95% Confidence Interval: $1.14{\sim}5.99$). In the univariate analysis, using the log-rank test, those with an adenocarcinoma showed a relatively longer median survival time than those of a non-adenocarcinoma (4.067 vs. 1.867 months, p=0.067) without statistical significance. In the multivariate analysis, using the Cox regression, those with a non-adenocarcinoma showed a trend of high risk of cancer death than those with an adenocarcinoma without statistical significance (Relative risk; 2.754, 95% Cl: $0.988{\sim}7.672$, p=0.053). Conclusion: We could not find an independent prognostic factor of malignant pleural effusion in NSCLC. As there was a trend of high risk of cancer death according to histology, further study will be needed.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.469-475
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• 1998

Purpose : To determine the role of Pelvic irradiation in stage I or IIA cervical carcinoma with pelvic nodal metastasis after hysterectomy and bilateral pelvic lymphadenectomy. Materials and Methods : This is a retrospective study of 68 cervical carcinoma patients who were found to have pelvic nodal metastasis at hysterectomy and received pelvic irradiation from 1983 to 1996 at Inje University Seoul Paik Hospital. External beam radiation therapy to pelvis was delivered using 4 MeV Linac and intracavitary irradiation was given via vaginal ovoids or cylinders. Five-year survival and disease-free survival were estimated by Kaplan-Meier Method and prognostic factors related to survival were analysed by log-rank test and Cox proportional hazards regression model. Results : Median length of follow-up was 52months. Five-year overall survival and disease-free survival (DFS) were 81.8$\%$ and 81.7$\%$ respectively. Patients with endometrial invasion had a 57.1$\%$ 5-year DFS compared to 87.5$\%$ for those without endometrial invasion (p=0.0074). Multivariate analysis revealed endometrial invasion as an only statistically significant prognostic factor for 5-year DFS. Among total 15 (22$\%$) recurrences. pelvic recurrences occurred in 4 cases and distant metastases occurred in 13 cases. Conclusion : We have been able to confirm previous results demonstrating marked decrease in local recurrence after pelvic irradiation. In view of the high proportion of distant metastasis found in this study, a trial of aggressive adjuvant systemic therapy and irradiation in early stage cervical carcinoma patients with pelvic nodal metastasis, especially with endometrial invasion, appears to be warranted.