• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.331-340
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• 2023

Predicting the survival time of a person in water (PIW) in maritime search and rescue (SAR) operations is an important concern. Although there have been many studies on survival models in marine-developed countries, it is difficult to apply them to Koreans in Korea's oceans because they were developed using marine distress data from the United Kingdom, United States, and Canada. Data on the survival time of a P IW were collected through interviews and surveys with a special rescue team from the Korea Coast Guard, SAR cases, press releases, and Korea Meteorological Administration data to address these issues. The maximum survival time (Korean) equation was developed by performing a regression analysis of this data, and the applicability to actual marine distress was reviewed and compared to the overseas survival model. By comprehensively using the maximum survival time (Korean), domestic SAR cases, and overseas survival models, guidelines for survival time and intensive and recommended search time were suggested. The study findings can contribute to decision-making, such as the input for search and rescue units. The findings can also help to determine the end of or reductions in SAR operations and explain policy decisions to the public and families of a PIW.

• Journal of Korean Neurosurgical Society
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• v.51 no.3
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• pp.127-134
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• 2012

Objective: To analyze the prognostic factors thought to be related with survival time after a spinal metastasis operation. Methods: We retrospectively analyzed 217 patients who underwent spinal metastasis operations in our hospital from 2001 to 2009. Hematological malignancies, such as multiple myeloma and lymphoma, were excluded. The factors thought to be related with postoperative survival time were gender, age (below 55, above 56), primary tumor growth rate (slow, moderate, rapid group), spinal location (cervical, thoracic, and lumbo-sacral spine), the timing of radiation therapy (preoperative, postoperative, no radiation), operation type (decompressive laminectomy with or without posterior fixation, corpectomy with anterior fusion, corpectomy with posterior fixation), preoperative systemic condition (below 5 points, above 6 points classified by Tomita scoring), pre- and postoperative ambulatory function (ambulatory, non-ambulatory), number of spinal metastases (single, multiple), time to spinal metastasis from the primary cancer diagnosis (below 21 months, above 22 months), and postoperative complication. Results: The study cohort mean age at the time of surgery was 55.5 years. The median survival time after spinal operation and spinal metastasis diagnosis were 6.0 and 9.0 months. In univariate analysis, factors such as gender, primary tumor growth rate, preoperative systemic condition, and preoperative and postoperative ambulatory status were shown to be related to postoperative survival. In multivariate analysis, statistically significant factors were preoperative systemic condition (p=0.048) and postoperative ambulatory status (p<0.001). The other factors had no statistical significance. Conclusion: The factors predictive for postoperative survival time should be considered in the surgery of spinal metastasis patients.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1545-1549
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• 2014

Background: Published studies on clinical outcome of helical tomotherapy for lung cancer are limited. The purpose of this study was to evaluate clinical outcomes and treatment-related toxicity in inoperable non-small cell lung cancer (NSCLC) patients treated with helical tomotherapy in Korea. Materials and Methods: Twenty-seven patients with NSCLC were included in this retrospective study. Radiotherapy was performed using helical tomotherapy with a daily dose of 2.1-3 Gy delivered at 5 fractions per week resulting in a total dose of 62.5-69.3 Gy. We assessed radiation-related lung and esophageal toxicity, and analyzed overall survival, locoregional recurrence-free survival, distant metastasis-free survival, and prognostic factors for overall survival. Results: The median follow-up period was 28.9 months (range, 10.1-69.4). The median overall survival time was 28.9 months, and 1-, 2-, and 3-year overall survival rates were 96.2%, 92.0%, and 60.0%. The median locoregional recurrence-free survival time was 24.3 months, and 1-, 2-, and 3-year locoregional recurrence-free survival rates were 85.2%, 64.5%, and 50.3%. The median distant metastasis-free survival time was 26.7 months, and 1-, 2-, and 3-year distant metastasis-free survival rates were 92.3%, 83.9%, and 65.3%, respectively. Gross tumor volume was the most significant prognostic factor for overall survival. No grade 4 or more toxicity was observed. Conclusions: Helical tomotherapy in patients with inoperable NSCLC resulted in high survival rates with an acceptable level of toxicity, suggesting it is an effective treatment option in patients with medically inoperable NSCLC.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1445-1450
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• 2000

Objectives : The Objective of this study was to analyze the prognostic factors affecting survival in the patients with glioblastomas. Methods : We retrospectively studied 55 consecutive patients with glioblastomas who were admitted to neurosurgery department from January 1988 to March 1998. Fifteen pateients were excluded from the analysis because of follow-up loss and surgical motality. There were 24 male and 16 female patients, with a mean age of 51 years. Surgery consisted of biopsy in 4(10.0%) patients, subtotal resection in 9(22.5%) patients and gross total resection in 27(67.5%) patients. Nine(22.5%) patients received second operation. Twenty-eight(70%) received postoperative radiation therapy. Various levels of radiation dose were used, 6,000 rad over 7 weeks in most cases. The variable factors were examined for their relationship with survival ; age at the time of diagnosis, gender, duration of neurological symptoms, preoperative neurological state(Karnofsky performance score), extent of surgical resection, location of tumor, reoperation, and postoperative radiotherapy and chemotherapy. Result : The mean survival time was 55 weeks, three(7.5%) of the 40 patients survived more than two years. Survival time with biopsy only cases was 24 weeks, for those with subtotal resection 43 weeks, and for those with gross total resection 67 weeks. A mean survival time from the time of reoperation was 42 weeks. Statistically significant survival factors in glioblastoma were extent of surgical resection, postoperative radiotherapy and reoperation. Summary : Results of our series support the views that the extent of surgery, reoperation and postoperative radiation are important prognostic factors. We also recommend radical tumor removal, postoperative radiotherapy and reoperation, if possible.

• The Journal of Korean Medicine
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• v.23 no.4
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• pp.91-97
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• 2002

Objective: This study was conducted to know the survival probability of the patients with cerebrovascular disease. Method: 1,341 patients who were suspected of having cerebrovascular disease clinically were investigated by telephone and NHIC (National Health Insurance Corporation) data. Conclusion: 1. The study population was grouped as 'Negative Brain CT findings' (11.8%), 'Hemorrhage' (12.4%) and 'Infarction' (75.7%). 2. The survival probabilities calculated by the Life Table method were statistically significant among brain CT finding groups (P<0.01). 3. The mean survival time calculated by the Kaplan-Meier method were also statistically significant among brain CT finding groups (P<0.01). 4. The result of Cox regression model was that sex (OR=0.7), age (OR=1.07), diabetes mellitus (OR=1.38), and heart disease (OR=1.69) affected the survival of the patients with cerebrovascular disease.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3923-3926
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• 2015

Background: Lung cancer is a fatal malignancy with high mortality and short survival time. The aim of this study was to estimate survival rates of Iranian patients with lung cancer and its associate predictive factors. Materials and Methods: The study was conducted on 355 patients admitted to hospitals of West Azerbaijan in the year 2007. The patients were followed up by phone calls until the end of June 2014. The survival rate was estimated using the Kaplan-Meier method and log-rank test for comparison. The Cox's proportional hazard model was used to investigate the effect of various variables on patient survival time, including age, sex, Eastern Cooperative Oncology Group (ECOG) performance, smoking status, tumor type, tumor stage, treatment, metastasis, and blood hemoglobin concentration. Results: Of the 355 patients under study, 240 died and 115 were censored. The mean and median survival time of patients was 13 and 4.8 months, respectively. According to the results of Kaplan-Meier method, 1, 2, and 3 years survival rates were 39%, 18%, and 0.07%, respectively. Based on Cox regression analysis, the risk of death was associated with ECOG group V (1.83, 95% CI: 1 Conclusions: The survival time of the patients with lung cancer is very short. While early diagnosis may improve the life expectancy effective treatment is not available.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6445-6449
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• 2015

Background: NSCLC is a disease involving uncontrolled cell growth, which could result in metastases into nearby tissues beyond the lungs. Materials and Methods: The aim of the present study was to analyze the influence of epidermal growth factor receptor (EGFR) gene expression on metastasis and survival in NSCLC patients. The present case-control study included 100 cases of NSCLC patients and 100 age and sex matched controls. EGFR gene expression was analyzed by quantitative real time PCR using serum RNA. Association with NSCLC patient survival was analyzed by the Kaplan-Meier method. Results: We analyzed EGFR gene expression and observed mean increased gene expression of 13.5 fold in NSCLC patients. Values reflected overall survival of patients with a median of 15.8 months in the cases of <13 fold increased gene expression vs 6.7 months with >13 fold increased EGFR gene expression (p=0.005). Distant metastatic patients with <13 fold increased EGFR gene expression had 7.9 months of median survival time while>13 fold increased EGFR gene expression had only 5 months of median survival time (p=0.03). Non metastatic patients with <13 fold increased EGFR gene expression had 18 months of median survival time as compared to only 7.1 months with >13 fold increased expression. Conclusions: Higher cell free EGFR mRNA expression may play an important role in causing distant metastases and reducing overall survival of NSCLC patients in the Indian population.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.1-30
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• 2003

This study attempts to understand factors influencing the persistence of companie's outsourcing arrangements using the techniques of survival analysis. It provides an insight into the dynamics of outsourcing relationships between clients and vendors. This is particularly relevant considering that current IS sourcing arrangements are strategic and long term, and require close interdependent relationships between the client and the vendor.

• Journal of Chest Surgery
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• v.32 no.10
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• pp.916-923
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• 1999

Background: Many institutes are interested in lung metastatectomy than before because of the improved long term survival, low mortality, and low morbidity after lung metastatectomy. However, prognostic factors affecting long term survival are controversial. We attempt to analyze the prognostic factors affecting retrospectively by comparing the results of lung metastasectomy. Material and Method: Between Jan. 1990 and Dec. 1997, 74 operations were taken in 63 patients with pulmonary metastases in various primary sites. We analyzed the postoperative long term survival according to sex, cell type, laterality, disease free interval(DFI), operation, the number of metastases, and the size of the largest metastasis. Result: There were 27 male and 36 female patients. Sex did not appeared to affect survival time(p=0.849). The primary tumor was carcinoma in 32, sarcoma in 28, and others in 3. Cell type, considering carcinoma and sarcoma, did not relate to survival time(p=0.071). DFI had no influence on the outcome(p=0.902). The type of operative procedure had no influence on the outcome(p=0.556). The laterality of metastases, 47 unilateral(74.6%) and 16 bilateral(25.4%), had no influence on the outcome(p=0.843). The number of metastases excised(one, two or three, four or more) did not appear to affect survival(p=0.263). The size of largest metastasis(<=10mm, 11mm-30mm, and >30mm) did not appear to affect survival(p=0.751). Previous factors were evaluated in both the carcinoma and sarcoma patients respectively. DFI was the only significant prognostic factor in metastatic lung sarcoma(p=0.0026). Conclusion: Survival was not related to sex, cell type, laterality, DFI, operative procedure, number of metastases, nor the size of the largest metastasis. DFI was related to the survival time in sarcoma group but further study is needed.

• Journal of the Korean Data and Information Science Society
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• v.25 no.5
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• pp.1151-1160
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• 2014

In DNA microarray studies, the number of genes far exceeds the number of samples and the gene expression measures are highly correlated. Partial least squares regression (PLSR) is one of the popular methods for dimensional reduction and known to be useful for the classifications of microarray data by several studies. In this study, we suggest a modified version of the partial least squares regression to analyze gene expression data with survival information. The method is designed as a new gene selection method using PLSR with an iterative procedure of imputing censored survival time. Mean square error of prediction criterion is used to determine the dimension of the model. To visualize the data, plot for variables superimposed with samples are used. The method is applied to two microarray data sets, both containing survival time. The results show that the proposed method works well for interpreting gene expression microarray data.