• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.521-531
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• 2010

Interval-censored observations are common in medical and epidemiologic studies; however, limited studies exist due to the complexity and special structure of interval-censoring. This paper introduces the imputation method and the self consistency method in the interval-censored data. We propose a new method of generating random numbers under an interval-censoring set-up. Through simulation studies we compare two methods under various simulation schemes in the sense of the mean squared error for estimating the median survival time and the mean integrated squared error for estimating the survival function. Under a moderate censoring percentage, the mean imputation method showed a better performance than the self-consistency method in estimating the median survival time and the survival function.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.403-411
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• 2023

Background: The concept of oligo-recurrence has not been generally applied in esophageal cancer. This study aimed to determine the prognostic significance of the number of recurrences in esophageal cancer. Methods: Patients with squamous cell carcinoma who underwent curative esophagectomy with R0 or R1 resection and who experienced a confirmed recurrence were included. The study included 321 eligible participants from March 2001 to December 2019. The relationship between the number of recurrences and post-recurrence survival was investigated. Results: The mean age was 63.8±8.1 years, and the majority of the participants (97.5%) were men. The median time to recurrence was 10.7 months, and the median survival time after recurrence was 8.8 months. Multiple recurrences with simultaneous local, regional, and distant locations were common (38%). In terms of the number of recurrences, single recurrences were the most common (38.3%) and had the best post-recurrence survival rate (median, 17.1 months; p<0.001). Patients with 2 or 3 recurrences showed equivalent survival to each other and longer survival than those with 4 or more (median, 9.4 months; p<0.001). In the multivariable analysis, the significant predictors of post-recurrence survival were body mass index, minimally invasive esophagectomy, N stage, R0 resection, post-recurrence treatment, and the number of recurrences (p<0.05). Conclusion: After esophagectomy, the number of recurrences was the most significant risk factor influencing post-recurrence survival in patients with esophageal cancer. In esophageal cancer, oligo-recurrence can be defined as a recurrence with three or fewer metastases. More intensive treatment might be recommended if oligo-recurrence occurs.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3357-3360
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• 2012

Objective: This study was to present the survival of advanced cancer patients and explore the influence of various factors on survival time as well as survival rate. The results provide guidelines for clinical practice of cancer treatment. Methods: Follow-up of 674 advanced cancer patients was performed in a hospice. The median survival time and survival rate were calculated, and survival analysis was carried out. Results: The median survival time of all patients dying from cancer was 12.0 months and the average survival time was 25.1 months. The 1-year cumulative survival rate was $0.518{\pm}0.020$ and the 5-year cumulative survival rate was $0.088{\pm}0.012$. The following factors showed significant impacts on survival rate: gender, age, primary diagnosis, surgery and the time when pain appeared. Conclusions: The survival time of patients with advanced cancer was relatively short. Major approaches to extend the survival time include early detection, early diagnosis, effective surgical treatment, pain control, reasonable supply of nutrients and multiple interventions.

• Journal of Korean Neurosurgical Society
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• v.47 no.5
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• pp.325-331
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• 2010

Objective : We retrospectively evaluated the survival outcome of patients with brain metastasis from hepatocellular carcinoma (HCC). Methods : Between 1991 and 2007, a total of 20 patients were diagnosed as having brain metastasis from HCC. The mean age of the patients was 55 ${\pm}$ 13 years, and 17 (85.0%) were men. Seventeen (85.0%) patients had already extracranial metastases. The median time from diagnosis of HCC to brain metastasis was 18.5 months. Fourteen (70.0%) patients had stroke-like presentation due to intracerebral hemorrhage (ICH). Ten (50.0%) patients had single or solitary brain metastasis. Among a total of 34 brain lesions, 31 (91.2%) lesions had the hemorrhagic components. Results : The median survival time was 8 weeks (95% CI, 5.08-10.92), and the actuarial survival rates were 85.0%, 45.0%, 22.5%, and 8.4% at 4, 12, 24, and 54 weeks. Age < 60 years, treatment of the primary and/or extracranial lesions, and recurrent ICH were the possible prognostic factors (p = 0.044, p < 0.001, and p = 0.111, respectively). The median progression-free survival (PFS) time was 3 months (95% CI, 0.95-5.05). Conclusion : The overall survival of the patients with brain metastasis from HCC was very poor with median survival time being only 8 weeks. However, the younger patients less than 60 years and/or no extracranial metastases seem to be a positive prognostic factor.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.67-71
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• 2000

Termiticidal activities of Chamaecyparis obtusa were quantitatively evaluated, and the activity differences between supporting materials such as woodmeal and filter paper or between species were defined based on the termiticidal activity value(TAV). It was found that TAV was high in the following order ; C. obtusa>Litsea coreana>C. obtusa var. formosensis>Ternstroemia gymnanthera. In particular, termiticidal activity of C. obtusa heartwood was stronger by 5 to 9 times than that of other three species. Median survival dosage(MSD) of C. obtusa was 108.8 mg. In case of woodmeal or filter paper tests with C. obtusa, termiticidal activities were inversely proportional to logarithms values of an added sample weight and median survival time(MST). The difference of termiticidal activities between woodmeal and filter paper in the methanol extracts was small, but that in the neutral fraction was enormous as 3.21 times. However, termiticidal activity of neutral fraction was corresponded to 17 to 53% of original woodmeal, and 47 to 83% of termiticidal activity was considered as a loss in test process.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.838-845
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• 1999

To determine the prognostic factors for survival of dogs infected with canine parvovirus, clinical and laboratory data of 35 dogs with clinical signs compatible with canine parvoviral enteritis admitted to the Veterinary Medical Teaching Hospital, Seoul National University during the period 1997-1998 were collected. Dogs were grouped by some major covariates, which can be considered as guides to the relative prognosis of dogs in the different subgroups. The Kaplan-Meier survival analysis and Weibull proportional hazard model were used to estimate overall survival, evaluate the comparability between groups, and identify potential prognostic factors. The overall survival rate for all dogs was 45.7% over the study period, and the Kaplan-Meier estimate of one week survival was 0.4989. Gender was the most favorable prognosis ; male dog (median, 6 days) had significantly higher risk of dying than female dog (median, 17 days ; p = 0.0023). In addition to gender, age was significantly associated with survival, with juvenile dogs less than 6-month-old having higher risk (p = 0.0359). Dogs that vaccinated with complete protocol (p = 0.0374) and those of having higher value of mean corpuscular volume (p = 0.0346) were found to be of prognostic importance. The 7 dogs in which white blood cell count of less than 2000 had shorter median survival time (3 days) than the remaining 28 dogs (8 days), but no statistical significance was found between leukopenic and survival. The distribution of packed cell volume and hemoglobin measurement was such that the overall risk of dying in the two groups was comparable. Further studies are needed to more accurately assess these results.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1309-1312
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• 2016

Inflammation can play an important role in cancer progression and the prognostic importance of neutrophil to lymphocyte ratio (NLR), a marker of inflammation, in cancer is a current investigation topic. In the present study, we aimed to determine whether there is a prognostic link between NLR and metastatic gastric cancer (mGC). A total of 143 patients from the Akdeniz University and Antalya Training and Research Hospital database were retrospectively analyzed. The median NLR value was 3.34. The median overall survival (OS) and median progression-free survival (PFS) were 11.6 and 7.9 months, respectively, in patients with NLR<3.34 while these values were 8.3 and 6.2 months respectively in patients with NLR>3.34 (p<0.001 and p=0.011, respectively). Our study showed that increased NLR is an independent prognostic factor associated with short survival in patients with mGC.

• Journal of Chest Surgery
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• v.33 no.4
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• pp.301-305
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• 2000

Background: The surgical indications of stage IV non-small cell lung cancer(NSCLC) are extremely limited with its controversial results. We analyzed the surgical results and survival in selected patients with resectable stage IV NSCLC. Material and Method: We reviewed the medical records of 21 patients who underwent operation for stage IV NSCLC from Jan. 1992 to Sep. 1999. Result: The mean age of patients was 55.6 years(range: 35 to 78). Sixteen were men and 5 were women. Tissue types were squamous cell carcinoma in 10(45.5%), adenocarcinoma in 9(40.9%), large cell carcinoma in 1 and carcinosarcoma in 1. Distant metastatic lesions were ipsilateral other lobe of lung in 18, brain in 2 and adrenal gland in 1. Pneumonectomy was performed in 16 patients, bilobectomy in 3, and lobectomy in 2 who underwent previous operatin for brain metastasis. Mean follow-up duration was 21.2$\pm$17.7 months. During follow-up period, 13 patients died. Three-and 5-year survival of patients were 38.0% and 19.0%, the median survival time was 19.1$\pm$7.8 months. In the group with ipsilateral pulonary metastasis(PM, n=18), 3- and 5-year survival of patients with N0 and N1(n=9) disease were 64.8% and 32.4%, median survival time was 55.3$\pm$27.2 months. Three-year survival of patients with N2(n=9) disease was 11.1%, median survival time was 10.6$\pm$0.3 months. The survival of N0 and N1 disease group was significantly better than that of N2 disease group(p=0.042). Also the disease free survival of N0 and N1 was significantly better than that of N2 disease in overall group(53.3 months vs 12.1 months, p=0.036) and ipsilateral PM group(63.4 months vs 8.8 months, p=0.001). Conclusion: We suggest that surgical treatment is worthful modality in well selected patients with stage IV NHSCLC especially with ipsilateral PM and N0 or N1 disease,. Nevertheless our study indicate questions that will need to be experienced further in larger studies.

• Journal of Korean Neurosurgical Society
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• v.53 no.4
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• pp.228-234
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• 2013

Objective : We have limited understanding on the presentation and survival of primary spinal sarcomas. The survival, recurrence rate, and related prognostic factors were investigated after treatment for primary sarcomas of the spine. Methods : Retrospective analysis of medical records and radiological data was done for 29 patients in whom treatment was performed due to primary sarcoma of the spine from 2000 to 2010. As for treatment method, non-radical operation, radiation therapy, and chemotherapy were simultaneously or sequentially combined. Overall survival (OS), progression free survival (PFS), ambulatory function, and pain status were analyzed. In addition, factors affecting survival and recurrence were analyzed : age (${\leq}42$ or ${\geq}43$), gender, tumor histologic type, lesion location (mobile spine or rigid spine), weakness at diagnosis, pain at diagnosis, ambulation at diagnosis, initial treatment, radiation therapy, kind of irradiation, surgery, chemotherapy and distant metastasis. Results : Median OS was 60 months, the recurrence rate was 79.3% and median PFS was 26 months. Patients with distant metastasis showed significantly shorter survival than those without metastasis. No factors were found to be significant relating to recurrence. Prognostic factor associated with walking ability was the presence of weakness at diagnosis. Conclusion : Primary spinal sarcomas are difficult to cure and show high recurrence rate. However, the development of new treatment methods is improving survival.

• Journal of Gastric Cancer
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• v.17 no.1
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• pp.21-32
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• 2017

Purpose: Perioperative chemotherapy improves survival outcomes in locally advanced (LA) gastric cancer. Materials and Methods: We retrospectively analyzed patients with LA gastric cancer who were offered perioperative chemotherapy consisting of epirubicin, oxaliplatin, and capecitabine (EOX) from May 2013 to December 2015 at Tata Memorial Hospital in Mumbai. Results: Among the 268 consecutive patients in our study, 260 patients (97.0%) completed neoadjuvant chemotherapy, 200 patients (74.6%) underwent D2 lymphadenectomy, and 178 patients (66.4%) completed adjuvant chemotherapy. The median follow-up period was 17 months. For the entire cohort, the median overall survival (OS), 3-year OS rate, median progression-free survival (PFS), and 3-year PFS rate were 37 months, 64.4%, 31 months, and 40%, respectively. PFS and OS were significantly inferior in patients who presented with features of obstruction than in those who did not (P=0.0001). There was no difference in survival with respect to tumor histology (well to moderately differentiated vs. poorly differentiated, signet ring vs. non-signet ring histology) or location (proximal vs. distal). Survival was prolonged in patients with an early pathological T stage and a pathological node-negative status. In a multivariate analysis, postoperative pathological nodal status and gastric outlet obstruction on presentation significantly correlated with survival. Conclusions: EOX chemotherapy with curative resection and D2 lymphadenectomy is a suggested alternative to the existing perioperative regimens. The acceptable postoperative complication rate and relatively high resections, chemotherapy completion, and survival rates obtained in this study require further evaluation and validation in a clinical trial.