Impact of the time interval from completion of neoadjuvant chemotherapy to initiation of postoperative adjuvant chemotherapy on the survival of patients with advanced ovarian cancer

Lee, Yong Jae,Chung, Young Shin,Lee, Jung-Yun,Nam, Eun Ji,Kim, Sang Wun,Kim, Sunghoon,Kim, Young Tae Elsevier 2018 Gynecologic oncology Vol.148 No.1

<P><B>Abstract</B></P> <P><B>Objective</B></P> <P>To investigate the relationship of the time interval from the completion of neoadjuvant chemotherapy (NAC) to the initiation of postoperative adjuvant chemotherapy (POAC) with the survival outcomes in patients with ovarian cancer.</P> <P><B>Methods</B></P> <P>We retrospectively investigated 220 patients with pathologically confirmed epithelial ovarian cancer who received NAC at Yonsei Cancer Hospital between 2006 and 2016. The time interval was defined as the period from the completion of NAC, spanning interval debulking surgery (IDS), to the initiation of POAC.</P> <P><B>Results</B></P> <P>The median time interval was 42 (range 16–178) days; 103 patients (53.1%) received POAC within 42days after NAC while 91 patients (46.9%) received it after 42days. There were no significant differences in patient characteristics between these 2 groups. Kaplan-Meier analysis showed that patients with longer time intervals (>42days) had poorer progression-free survival and overall survival (P=0.039 and 0.005, respectively). In the multivariate analysis, patients with longer time intervals had significantly poorer progression-free (hazard ratio, 1.41; 95% confidence interval, 0.98–2.03; not significant) and overall survivals (hazard ratio, 2.03; 95% confidence interval, 1.16–3.54). When the patients were categorized according to time interval quartiles (≤37, 38–42, 43–50, and >50days), longer time intervals were associated with higher risks of recurrence and death (P for trend: 0.006 and <0.001, respectively).</P> <P><B>Conclusion</B></P> <P>The time interval from the completion of NAC to the initiation of POAC appears to influence survival. Efforts to reduce the time interval might improve the outcomes in ovarian cancer patients undergoing NAC.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We examined the relationship between the NAC-POAC interval and survival. </LI> <LI> Patients with intervals >42days showed poorer progression-free and overall survival. </LI> <LI> Longer time intervals were thus associated with higher risks of recurrence and death. </LI> </UL> </P>

18시간까지의 허혈시간이 재접합 수지의 생존율에 미치는 영향

박정일,이동철,김진수,기세휘,노시영,양재원 대한성형외과학회 2011 Archives of Plastic Surgery Vol.38 No.5

Purpose: There are multiple dependent variables commonly attributed to survival of replanted digits. The ischemia time is thought to be a clinically relevant factor. However, controversy exists as large hand centers have reported successful replant outcomes independent of ischemic time. In this study, we present a single institution experience on the effect of ischemia time on the survival of completely amputated digits. Methods: A retrospective review of a single institution experience was performed. This cohort included all comers who had suffered complete amputation of a digit (Zone 2-4) and underwent replantation from 2003 to 2009. Demographic information as well as injury mechanism, ischemic time, and replantation outcome were recorded for each patient. Chi-square was used to analyze the result. Results: Mean age was 35.5 years old (2-69). Mean replantation survival was 89.5% (37/317). Survival rates were 94, 88, and 88% in respective groups of 0~6, 6~12, of > 12 hours of ischemia time. In chi-square analysis, there was no difference with p value of 0.257. No other independent patient factors showed statistically significant relationship to replant survival rate. In the group with longest ischemia time (12~18 hours) replant survival rate was 88% (37/42). Conclusion: Prolonged ischemia time is commonly believed to be a contributing factor for replant survival. However, our experience has shown that survival rate is uniform up to 18 hours of ischemia.

한국 펀드 시장에서의 생존분석에 관한 연구

김성신(Sungsin Kim) 대한경영학회 2016 大韓經營學會誌 Vol.29 No.12

암환자의 진단-치료 소요기간에 따른 생존분석과 지역사회별 격차 및 시계열적 추이

김우림 ( Woorim Kim ),한규태 ( Kyu-tae Han ) 한국보건행정학회 2021 보건행정학회지 Vol.31 No.1

Background: The Korean government introduced National Cancer Control Program and strengthening national health insurance coverage for cancer patients. Although many positive effects have been observed, there are also many concerns about cancer management such as patient concentration or time-to-treatment. Thus, we investigated the association between the time-to-treatment and survival of cancer patients, and compared regional differences by time trend. Methods: The data used in this study were national health insurance claims data that included patients diagnosed with lung cancer and received surgical treatment between 2005 and 2015. We conducted survival analysis with Cox proportional hazard model for the association between time-to-treatment and survival in lung cancer. Additionally, we compared the regional differences for time-to-treatment by time trend. Results: A total of 842 lung cancer patients were included, and 52.3% of lung cancer patients received surgical treatment within 30 days. Patients who received surgical treatment after 31 days had higher 5-year or 1-year mortality compared to treatment within 30 days (5-year: hazard ratio [HR], 1.566; 1-year: HR, 1.555; p<0.05). There were some regional differences for time-to-treatment, but it was generally reduced after 2010. Conclusion: Delayed surgical treatment after diagnosis can negatively affect patient outcomes in cancer treatment. To improve cancer control strategies, there are needed to analyze the healthcare delivery system for cancer care considering the severity and types of cancer.

서로 다른 형태의 지방산 투여가 훈련된 흰쥐의 지구성 운동수행력, 안정시기와 운동스트레스 시기의 에너지 기질, Insulin 호르몬과 Lipase 활성에 미치는 영향

곽이섭,Kwak, Yi-Sub 한국생명과학회 2007 생명과학회지 Vol.17 No.3

본 연구는 장기간의 수영훈련을 마친 통제 훈련군, MCT 투여 훈련군 및 LCT 투여 훈련군에서 지구력 운동수행력과 장기간의 훈련 안정시기 및 운동스트레스 부여시기(실험동물이 상당한 스트레스를 느끼는 160분간의 강제수영)에서 에너지 기질의 변화, 인슐린 호르몬, 및 Lipase 효소의 활성화를 함께 비교하여, 만약 투여 훈련군에서 높은 운동수행력이 나왔다면 이것이 어느 에너지 기질 및 피로물질과 연관되는지 혹은 인슐린 호르몬과 지방분해 효소인 Lipase 효소와는 어떠한 연관이 있는지를 규명하여 지구성 운동수행력에 훈련과 투여효과를 과학적으로 검증하는 데에 연구목적이 있었다. 본 연구에서 사용된 실험동물은 평균체중 140-155 g의 Sprague-Dawley계 횐쥐 수컷으로(7 wk), SPF (Specific Pathogen Free: 특정병원체 부재동물)를 대한바이오링크에서 분양 받은 후에 D대학교 실험동물 사육실에서 사육하였다. 실험동물은 총 54마리를 환경적응과 적응훈련을 포함하는 총 9주간의 훈련을 거친 후 크게 세 그룹으로 나누어 비 투여 그룹 18마리, MCT 투여그룹 18마리, LCT 투여그룹 18마리로 구분하였고 각 그룹에서 안정 시기 6마리와 160분간의 운동 스트레스 시기 6마리 및 지구력 운동수행력시기(survival test) 6마리로 세분화 하여 분석하였다. 본 연구의 결과로 일반적인 지방 형태인 LCT의 투여는 추가적인 체중증가를 일으켰고, 운동수행력의 증가도 가져왔다. 하지만 같은 강도의 운동 부하에 대해서 운동 시 활용되는 지방의 형태인 지방산의 동원이 상대적으로 적었고, 운동증료시기에도 많은 양이 TG의 형태로 존재함을 알 수 있었다. 그리고 운동종료 시 피로물질인 젖산의 축적량이 증가하였고, 지방산화 효소인 Lipase 활성도도 크게 증가하지 않으면서 오히려 인슐린 호르몬을 증가시켜 많은 양의 에너지를 제공하여 지구력 운동 수행에는 도움을 주지만 효율성이 떨어짐을 알 수 있었다. 하지만 MCT의 투여는 인슐린 호르몬의 증가를 일으키지 않으면서 lipase 효소의 활성도를 증가시키고, 젖산 축적을 적게 하면서 유리지방산의 동원을 원활하게 하여 운동 지속시간을 상당히 연장했음을 알 수 있었다. 그리고 TG의 축적을 적게 일으키면서 체중의 감소도 나타났다. 이러한 결과를 통하여 장기간 지구성 운동시 추가적인 에너지 공급을 위해 MCT를 투여하는 것이 운동 수행력의 증가는 물론, 에너지 기질의 활성화를 도모하고 피로물질의 축적을 적게 일으켜, 효율적인 에르고게닉에이드로 권장된다. 뿐만 아니라 에너지 효율성을 증가하여 추가적인 지방축적을 일으키지 않기 때문에, 체중증가를 우려할 필요가 없으며, 오히려 많은 지방을 에너지로 사용하기 때문에 에너지 효율성의 면에서 운동만 한다면 다이어트에도 도움이 되리라 생각한다. The purpose of this study was to investigate the effects of different type of triglycerides (MCT & LCT) on weight, survival time, energy substrate (FFA, TG, pyruvate, lactate), insulin and lipase in the trained rats. Fifty-four Sprague-Dawley rats were divided into 3 groups: control group (CG, n=18), MCT supplement group (MG, n=18), and LCT supplement group (LG, n=18). They also were divided into 3 periods: trained resting (R, n=6) and trained & exercise load (E, n=6), and survival time test was performed to know the supplemented effects. Body weight of all animals was checked every week, MCT group and LCT group received supplementary MCT and LCT orally and preliminary swimming training for 6 days before the start of main experiment. All animals received 15-minute swimming training 5 times during first week of experiment, and swimming training time was increased 15 minutes every week until it reached 90 minutes at last 9th week. After last swimming training, animals were fasted for 12 hours and blood samples were taken from abdominal aorta in the Department of Animal Medicine at the D university Animal Center. Among the CGE, MGE, and LGE groups, the MGE had the greatest increase in physical performance time. In the FFA levels, there was significant differences(p<.05) in CG, MG and LG groups, and also there was major difference of FFA levels in the MG and LG. In the lipase levels, there was signifi.ant differences (p<.05) in CG, MG and LG groups. MG was the greatest than the other groups. In the insulin hormone levels, there was the great differences (p<.05) in LG compare to CG groups, whereas there was no significant difference in the CG and MG. In conclusion, these results suggest that regular prolonged physical training with MCT supplementation, improves exercise performance time through the increase of energy substrate utilization, lipase activity and FFA levels, irrespective of insulin hormone responses.

Methodology Proposal to Estimate Korean ICT Start-ups’ Survival: A Discrete-time Proportional Hazard Model

( Kyunghoon Kim ) 정보통신정책학회 2019 정보통신정책연구 Vol.26 No.3

This study is concerned with factors affecting start-ups’ survival, and with predicting their survival probability. A new proportional hazard model is proposed for analyzing the survival of information and communications technology (ICT) start-ups. This model overcomes the limitations of existing survival models in their utilization of information about firms’ activities, stemming from the fact that those models manipulate observations only in a continuous-time horizon. A discrete-time proportional hazard model is proposed to account exhaustively for firms’ activities within the study period. To show the superiority of the proposed discrete-time proportional hazard model over a benchmark continuous-time proportional hazard model, both models are applied to a clinical dataset and their log-likelihood values are compared. The proposed model is found to be better in terms of goodness-of-fit and predictive performance.

Survival analysis: part II – applied clinical data analysis

인준용,이동규 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.5

As a follow-up to a previous article, this review provides several in-depth concepts regarding a survival analysis. Also, several codes for specific survival analysis are listed to enhance the understanding of such an analysis and to provide an applicable survival analysis method. A proportional hazard assumption is an important concept in survival analysis. Validation of this assumption is crucial for survival analysis. For this purpose, a graphical analysis method and a goodnessof- fit test are introduced along with detailed codes and examples. In the case of a violated proportional hazard assumption, the extended models of a Cox regression are required. Simplified concepts of a stratified Cox proportional hazard model and time-dependent Cox regression are also described. The source code for an actual analysis using an available statistical package with a detailed interpretation of the results can enable the realization of survival analysis with personal data. To enhance the statistical power of survival analysis, an evaluation of the basic assumptions and the interaction between variables and time is important. In doing so, survival analysis can provide reliable scientific results with a high level of confidence.

Methodology Proposal to Estimate Korean ICT Start-ups’ Survival: A Discrete-time Proportional Hazard Model

김경훈 정보통신정책학회 2019 정보통신정책연구 Vol.26 No.3

This study is concerned with factors affecting start-ups’ survival, and with predicting their survival probability. A new proportional hazard model is proposed for analyzing the survival of information and communications technology (ICT) start-ups. This model overcomes the limitations of existing survival models in their utilization of information about firms’ activities, stemming from the fact that those models manipulate observations only in a continuous-time horizon. A discrete-time proportional hazard model is proposed to account exhaustively for firms’ activities within the study period. To show the superiority of the proposed discrete-time proportional hazard model over a benchmark continuous-time proportional hazard model, both models are applied to a clinical dataset and their log-likelihood values are compared. The proposed model is found to be better in terms of goodness-of-fit and predictive performance.

The survival impact of surgical waiting time in patients with resectable pancreatic head cancer

Hye Kyoung Seo,Dae Wook Hwang,Seo Young Park,Yejong Park,Seung Jae Lee,Jae Hoon Lee,Ki Byung Song,Young-Joo Lee,Song Cheol Kim 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.4

Backgrounds/Aims: After centralization policy, clinical outcomes have been improved in patients underwent pancreaticoduodenectomy for pancreatic cancer. However, centralization could exacerbate the prolongation of surgical waiting time. This study aims to investigate whether the shorter waiting time correlates with the better survival and to identify the major confounders that influence the association between those. Methods: In this retrospective cohort study, a total 554 patients with pathologically confirmed pancreatic ductal adenocarcinoma were assessed the eligibility from 2014 through 2015. Patients with neoadjuvant chemotherapy, body-tail resection, total pancreatectomy and combined adjacent organ resection were excluded. All patients were divided into two groups by median waiting time, 21 days, defined as the date difference between initial imaging diagnosis and operation. Results: Median overall survival did not differ between long and short waiting group (30.4 vs 24.8 months, p=0.35; HR=0.84, 95% CI=0.58-1.21). The proportion of cancer stage shifting, the difference between clinical and pathologic staging, did not differ depending on waiting time group (p=0.811 and 0.255, each of reviewers). Short waiting time was highly correlated with high initial clinical stage (Spearman correlation coefficients –0.201 (p=0.006) and –0.100 (p=0.175), each of reviewers). Conclusions: Initial clinical stage had confounding effect on the association between waiting time and overall survival. Therefore, in evaluating centralization policy at the national level, evidence for maximum acceptable waiting time should be investigated in the near future with considering that surgical waiting time could be affected by initial clinical stage.

Cox 모형을 활용한 고속도로 사고 처리시간 영향인자 분석

정연식,김선중 대한토목학회 2017 대한토목학회논문집 Vol.37 No.6

Duration induced by freeway crashes has a critical influence on traffic congestion. In general, crash duration composes detection and verification, response, and clearance time. Of these, the crash clearance time determined by a crash clearance team has attracted considerable attention in the freeway congestion management since the interest of the first two time stages faded away with increasing ubiquitous mobile phone users. The objective of this study is to identify the critical factors that affect freeway crash clearance time using a Cox’s proportional hazard model. In total, 6,870 crash duration data collected from 30 major Korean freeways in 2013 were used. As a result, it was found that crashes during the night, with trailer or larger size truck, and in tunnel section contribute to increasing clearance time. Crashes associated with fatality, completed damage of crashed vehicle (s), and vehicles’ fire or rollover after crash also lead to increasing clearance time. Additionally, an increase in the number of vehicles involved resulted in longer clearance time. On the other hand, crashes in the vicinity of tollgate, by passenger car, during spring, on flat section, and of car-facility type had longerclearance time. On the basis of the results, this paper suggested some strategic plans and mitigation measures to reduce crash clearance time on Korean freeway systems. 고속도로에서 발생된 교통사고 지속시간은 교통혼잡에 심각한 영향을 미친다. 일반적으로, 교통사고 지속시간은 사고의 검지시간, 대응시간, 처리시간으로 구성되며, 이 중 사고의 검지 및 대응시간은 최근 스마트폰 보급률 증가로 인해 매우 감소된 것으로 추정된다. 따라서 교통사고 처리팀에 의해 수행되는 사고 처리시간의 관리는 교통사고로 인한 교통혼잡 관리에 매우 중요한 요인이 된다. 본 연구는 고속도로 교통사고 처리에 영향을 미치는 주요 인자를 파악하는 것이 목적이다. 분석을 위해 2013년 전국 30개 주요 고속도로에서 발생한 총 6,870건의 자료를 이용하였다. 고속도로 사고 처리시간에 영향을 주는 인자 분석을 위해 Cox 모형을 활용하였다. 분석결과, 13개의 변수가 교통사고 처리시간에 영향을 미치는 것으로 나타났으며, 사고 처리시간을 증가시키는 요인은 터널에서 발생한 사고, 사망자가 발생한 사고, 사고차량수, 사고 후 상태의 상태가 전도 혹은 화재로 이어진 사고, 차량이 완파된 사고, 화물(대형) 및 트레일러 사고, 야간에 발생한 사고인 것으로 나타났다. 반면, 톨게이트에서 발생한 사고, 차-시설 사고, 승용차 사고, 종단구배가 평탄한 구간에서 발생한 사고는 다른 환경에서 발생한 사고보다 사고 처리시간을 감소시키는 것으로 나타났다. 이러한 결과는 고속도로에서 사고 발생 시 혼잡에 영향을 줄 수 있는 사고 처리시간의 감소 전략 수립을 위한 기반정보로 활용할 수 있을 것으로 기대된다.