• Journal of Preventive Medicine and Public Health
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• v.51 no.4
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• pp.205-212
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• 2018

Objectives: The main purpose of this study was to quantify the risk of mortality linked to various regimens of hypertonic peritoneal dialysis (PD) solution. Methods: A retrospective cohort study of patients using home-based PD was carried out. The prescribed regimen of glucose-based PD solution for all patients, determined on the basis of their individual conditions, was extracted from their medical chart records. The primary outcome was death. The treatment regimens were categorized into 3 groups according to the type of PD solution used: original PD (1.5% glucose), shuffle PD (1.5 and 2.5% glucose), and serialized PD (2.5 and 4.5% glucose). Multivariate analysis (using the Weibull model) was applied to comprehensively examine survival probabilities related to the explanatory variable, while adjusting for other potential confounders. Results: Of 300 consecutive patients, 38% died over a median follow-up time of 30 months (interquartile range: 15-46 months). Multivariate analysis showed that a treatment regimen with continued higher-strength PD solution (serialized PD) resulted in a lower survival rate than when the conventional strength solution was used (adjusted hazard ratio, 2.6; 95% confidence interval, 1.6 to 4.6, p<0.01). Five interrelated risk factors (age, length of time on PD, hemoglobin levels, albumin levels, and oliguria) were significant predictors contributing to the outcome. Conclusions: Frequent exposure to high levels of glucose PD solution significantly contributed to a 2-fold higher rate of death, especially when hypertonic glucose was prescribed continuously.

• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.425-445
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• 2021

A generalization of the log-logistic (LL) distribution called exponentiated log-logistic (ELL) distribution on lines of exponentiated Weibull distribution is considered. In this paper, based on progressive type-II censored samples, we have derived the maximum likelihood estimators and Bayes estimators for three parameters, the survival function and hazard function of the ELL distribution. Then, under the balanced squared error loss (BSEL) and the balanced linex loss (BLEL) functions, their corresponding Bayes estimators are obtained using Lindley's approximation (see Jung and Chung, 2018; Lindley, 1980), Tierney-Kadane approximation (see Tierney and Kadane, 1986) and Markov Chain Monte Carlo methods (see Hastings, 1970; Gelfand and Smith, 1990). Here, to check the convergence of MCMC chains, the Gelman and Rubin diagnostic (see Gelman and Rubin, 1992; Brooks and Gelman, 1997) was used. On the basis of their risks, the performances of their Bayes estimators are compared with maximum likelihood estimators in the simulation studies. In this paper, research supports the conclusion that ELL distribution is an efficient distribution to modeling data in the analysis of survival data. On top of that, Bayes estimators under various loss functions are useful for many estimation problems.

• Journal of Gastric Cancer
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• v.18 no.1
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• pp.69-81
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• 2018

Purpose: It has been reported that the survival of patients with locally advanced gastric cancer (LAGC) is better in East Asia countries than in developed western countries; however, the prognosis of LAGC remains poor. This study aimed to evaluate the effects of perioperative chemotherapy on the long-term survival of East Asia patients with LAGC. Materials and Methods: From October 2006 through August 2008, 43 patients with LAGC received perioperative S-1 combined with weekly docetaxel in a phase II study (neoadjuvant group). These patients were matched using propensity scores to patients who underwent surgery without neoadjuvant chemotherapy during the same period (surgery group). The surgical outcomes and long-term survivals were compared between the 2 groups. Results: After matching, 43 and 86 patients were included in the neoadjuvant and surgery groups, respectively, and there was no significant difference in their baseline characteristics. Although the operating time was longer in the neoadjuvant group, there was no significant difference in postoperative complications between the 2 groups. The neoadjuvant group had a significantly higher 5-year overall survival (OS) rate (73.3% vs. 51.1%, P=0.005) and a trend towards higher 5-year progression-free survival (PFS) (62.8% vs. 49.9%, P=0.145). In the multivariate analysis, perioperative chemotherapy was an independent factor for OS, with a hazard ratio of 0.4 (P=0.005) and a marginal effect on the PFS (P=0.054). Conclusions: Perioperative chemotherapy was associated with better long-term survival without increasing postoperative complications in the setting of D2 surgery for patients with LAGC, suggesting that perioperative chemotherapy can be a therapeutic option in East Asia countries.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.78-85
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• 2017

Background: Closure of a secundum atrial septal defect (ASD) is possible through surgical intervention or device placement. During surgical intervention, concomitant pathologies are corrected. The present study was conducted to investigate the outcomes of surgical ASD closure, to determine the risk factors of mortality, and establish the effects of concomitant disease correction. Methods: Between October 1989 and October 2009, 693 adults underwent surgery for secundum ASD. Their mean age was $40.9{\pm}13.1years$, and 199 (28.7%) were male. Preoperatively, atrial fibrillation was noted in 39 patients (5.6%) and significant tricuspid regurgitation (TR) in 137 patients (19.8%). The mean follow-up duration was $12.4{\pm}4.7years$. Results: There was no 30-day mortality. The 1-, 5-, 10-, and 20-year survival rates were 99.4%, 96.8%, 94.5%, and 81.6%, respectively. In multivariate analysis, significant preoperative TR (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.09 to 3.16; p=0.023) and preoperative age (HR, 1.04; 95% CI, 1.01 to 1.06; p=0.001) were independent risk factors for late mortality. The TR grade significantly decreased after ASD closure with tricuspid repair. However, in patients with more than mild TR, repair was not associated with improved long-term survival (p=0.518). Conclusion: Surgical ASD closure is safe. Significant preoperative TR and age showed a strong negative correlation with survival. Our data showed that tricuspid valve repair improved the TR grade effectively. However, no effect on long-term survival was found. Therefore, early surgery before the development of significant TR mat be beneficial for improving postoperative survival.

• Journal of Hospice and Palliative Care
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• v.8 no.2
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• pp.200-208
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• 2005

Purpose: Palliative procedures or surgical interventions not only manage various symptoms of malignant gastrointestinal obstruction, but also improve the quality of life. We investigated the clinical characteristics and prognostic factors of terminal cancer patients with palliative procedures for malignant gastrointestinal obstruction. Methods: We retrospectively reviewed the medical records of 48 terminal cancer patients with palliative procedures for malignant gastrointestinal obstruction at Sam Anyang hospital from May in 2002 to May in 2005. We excluded patients with palliative tumor resection. We analyzed prognostic factors in symtom-free survival and overall survival using Kaplan-Meier method, univariate and multivariate analysis. Results: There were 25 males (52%) and 23 females (48%), and median age of 48 patients was 65 years. The most common cause of malignant gastrointestinal obstruction was colorectal (26 patients, 55%), followed by stomach (10, 21%). Twenty patients (42%) received previous treatment (chemotherapy, surgery, and radiotherapy) and 28 (58%) never received any. Eighteen of 20 had received chemotherapy. The most common symptom was pain (15 patients, 31%). Twenty three patients (48%) had Eastern Cooperative Oncology Group(ECOG) performance status of 1 or 2 score and 25 patients (52%) 3 or 4 score. The most common palliative procedure was colostomy and there was no mortality concerning the palliative procedures. By univariate and multivariate analysis, performance status was the only independent prognostic factor in overall survival and symptom-free survival. Overall survival was 150 days and symptom-free survival was 90 days. Conclusion:. We confirmed that perftatdormance status is significant independent prognostic factor in terminal cancer patients with palliative procedures for malignant gastrointestinal obstruction.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.604-615
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• 2022

BACKGROUND/OBJECTIVES: This study aimed to investigate cancer-specific survival (CSS) and associated risk factors in elderly gastric cancer (EGC) patients. SUBJECTS/METHODS: EGC patients (≥ 70 yrs) who underwent curative gastrectomy between January 2013 and December 2017 at our hospital were included. Clinicopathologic characteristics and survival data were collected. Receiver operating characteristic (ROC) analysis was used to extract the best cutoff point for body mass index (BMI). A Cox proportional hazards model was used to determine the risk factors for CSS. RESULTS: In total, 290 EGC patients were included, with a median age of 74.7 yrs. The median follow-up time was 31 (1-77) mon. The postoperative 1-yr, 3-yr and 5-yr CSS rates were 93.7%, 75.9% and 65.1%, respectively. Univariate analysis revealed risk factors for CSS, including age (hazard ratio [HR] = 1.08; 95% confidence interval [CI], 1.01-1.15), intensive care unit (ICU) admission (HR = 1.73; 95% CI, 1.08-2.79), nutritional risk screening (NRS 2002) score ≥ 5 (HR = 2.33; 95% CI, 1.49-3.75), and preoperative prognostic nutrition index score < 45 (HR = 2.06; 95% CI, 1.27-3.33). The ROC curve showed that the best BMI cutoff value was 20.6 kg/m². Multivariate analysis indicated that a BMI ≤ 20.6 kg/m² (HR = 2.30; 95% CI, 1.36-3.87), ICU admission (HR = 1.97; 95% CI, 1.17-3.30) and TNM stage (stage II: HR = 5.56; 95% CI, 1.59-19.43; stage III: HR = 16.20; 95% CI, 4.99-52.59) were significantly associated with CSS. CONCLUSIONS: Low BMI (≤ 20.6 kg/m²), ICU admission and advanced pathological TNM stages (II and III) are independent risk factors for CSS in EGC patients after curative gastrectomy. Nutrition support, better perioperative management and early diagnosis would be helpful for better survival.

• Radiation Oncology Journal
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• v.35 no.4
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• pp.306-316
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• 2017

Purpose: To investigate the predictive role of maximum standardized uptake value ($SUV_{max}$) of 2-[$^{18}F$]fluoro-2-deoxy-D-glucose($^{18}F-FDG$) positron emission tomography/computed tomography (PET/CT) in nasopharyngeal cancer patients treated with intensity-modulated radiotherapy (IMRT). Materials and Methods: Between October 2006 and April 2016, 53 patients were treated with IMRT in two institutions and their PET/CT at the time of diagnosis was reviewed. The $SUV_{max}$ of their nasopharyngeal lesions and metastatic lymph nodes (LN) was recorded. IMRT was delivered using helical tomotherapy. All patients except for one were treated with concurrent chemoradiation therapy (CCRT). Correlations between $SUV_{max}$ and patients' survival and recurrence were analyzed. Results: At a median follow-up time of 31.5 months (range, 3.4 to 98.7 months), the 3-year overall survival (OS) and disease-free survival (DFS) rates were 83.2% and 77.5%, respectively. In univariate analysis, patients with a higher nodal pre-treatment $SUV_{max}$ (${\geq}13.4$) demonstrated significantly lower 3-year OS (93.1% vs. 55.5%; p = 0.003), DFS (92.7% vs. 38.5%; p < 0.001), locoregional recurrence-free survival (100% vs. 50.5%; p < 0.001), and distant metastasis-free survival (100% vs. 69.2%; p = 0.004), respectively. In multivariate analysis, high pre-treatment nodal $SUV_{max}$ (${\geq}13.4$) was a negative prognostic factor for OS (hazard ratio [HR], 7.799; 95% confidence interval [CI], 1.506-40.397; p = 0.014) and DFS (HR, 9.392; 95% CI, 1.989-44.339; p = 0.005). Conclusions: High pre-treatment nodal $SUV_{max}$ was an independent prognosticator of survival and disease progression in nasopharyngeal carcinoma patients treated with IMRT in our cohort. Therefore, nodal $SUV_{max}$ may provide important information for identifying patients who require more aggressive treatment.

• Journal of Pathology and Translational Medicine
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• v.52 no.6
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• pp.396-403
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• 2018

Background: In the current American Joint Committee on Cancer staging system of breast cancer, only tumor size determines T-category regardless of whether the tumor is single or multiple. This study evaluated if tumor multiplicity has prognostic value and can be used to subclassify breast cancer. Methods: We included 5,758 patients with invasive breast cancer who underwent surgery at Samsung Medical Center, Seoul, Korea, from 1995 to 2012. Results: Patients were divided into two groups according to multiplicity (single, n=4,744; multiple, n=1,014). Statistically significant differences in lymph node involvement and lymphatic invasion were found between the two groups (p<.001). Patients with multiple masses tended to have luminal A molecular subtype (p<.001). On Kaplan-Meier survival analysis, patients with multiple masses had significantly poorer disease-free survival (DFS) (p=.016). The prognostic significance of multiplicity was seen in patients with anatomic staging group I and prognostic staging group IA (p=.019 and p=.032, respectively). When targeting patients with T1-2 N0 M0, hormone receptor-positive, and human epidermal growth factor receptor 2 (HER2)-negative cancer, Kaplan-Meier survival analysis also revealed significantly reduced DFS with multiple cancer (p=.031). The multivariate analysis indicated that multiplicity was independently correlated with worse DFS (hazard ratio, 1.23; 95% confidence interval, 1.03 to 1.47; p=.025). The results of this study indicate that tumor multiplicity is frequently found in luminal A subtype, is associated with frequent lymph node metastasis, and is correlated with worse DFS. Conclusions: Tumor multiplicity has prognostic value and could be used to subclassify invasive breast cancer at early stages. Adjuvant chemotherapy would be necessary for multiple masses of T1-2 N0 M0, hormone-receptor-positive, and HER2-negative cancer.

• Journal of Preventive Medicine and Public Health
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• v.49 no.6
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• pp.394-405
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• 2016

Objectives: The survival outcomes of antiretroviral treatment (ART) programs have not been systematically evaluated at the state level in India. This retrospective study assessed the survival rates and factors associated with survival among adult human immunodeficiency virus (HIV)-infected patients in Andhra Pradesh, India. Methods: The present study used data from 139 679 HIV patients aged ${\geq}15$ years on ART who were registered from 2007 to 2011 and were followed up through December 2013. The primary end point was death of the patient. Mortality densities (per 1000 person-years) were calculated. Kaplan-Meier and Cox-regression models were used to estimate survival and explore the factors associated with survival. Results: The overall median follow-up time was 16.0 months (2.0 months for the deceased and 14.0 months for those lost to follow-up). Approximately 13.2% of those newly initiated on ART died during follow-up. Of those deaths, 56% occurred in the first three months. The crude mortality rate was 80.9 per 1000 person-years at risk. The CD4 count (adjusted hazard ratio [aHR],4.88; 95% confidence interval [CI], 4.36 to 5.46 for < $100cells/mm^3$ vs. > $350cells/mm^3$), functional status (aHR, 3.05; 95% CI, 2.82 to 3.30 for bedridden vs. normal), and body weight (aHR, 3.69; 95% CI, 3.42 to 3.97 for <45 kg vs. >60 kg) were strongly associated with the survival of HIV patients. Conclusions: The study findings revealed that high mortality was observed within the first three months of ART initiation. Patients with poor baseline clinical characteristics had a higher risk of mortality. Expanded testing and counseling should be encouraged, with the goal of ensuring early enrollment into the program followed by the initiation of ART in HIV-infected patients.

• Radiation Oncology Journal
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• v.37 no.2
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• pp.110-116
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• 2019

Purpose: This study aimed to identify prognostic factors for locoregional recurrence (LRR) in pT3N0 rectal cancer patients who were treated with surgery alone and had negative resection margin including circumferential resection margin (CRM) for optimal indication of adjuvant radiotherapy. Materials and Methods: We reviewed patients with pT3N0 rectal cancer who were treated via upfront surgery and had no other adjuvant treatment from January 2003 to December 2012. In total, 122 patients who had negative resection margin including negative CRM were included in the analysis. Results: The median follow-up period after surgery was 60 months (range, 3 to 161 months). During this time, 6 patients (4.9%) experienced LRR at the anastomotic site (4 patients), and regional lymphatic area (2 patients). The estimated 5-year rates of overall survival, recurrence-free survival, and LRR-free survival were 96.7%, 84.6%, and 94.0%, respectively. Multivariate analysis showed that level of tumor ≤5 cm was a significant prognostic factor for LRR-free survival (LRRFS) (p = 0.04; hazard ratio = 7.08; 95% confidence interval, 1.06-47.30). Patients with level of tumor ≤5 cm had an estimated 5-year LRRFS of 66.8%, which was much higher than 2.3% in patients with level of tumor >5 cm. There was no significant factor for recurrence-free survival or overall survival. Conclusion: In T3N0 rectal cancer, adjuvant chemoradiotherapy should be recommended in patients with level of tumor ≤5 cm for better local control. However, in patients with pT3N0 disease, negative resection margin, and level of tumor >5 cm, adjuvant chemoradiotherapy should be carefully suggested.