• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7359-7363
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• 2015

Background: As a result of significant progress made in treatment of many types of cancers during the last few decades, there have been an increased number of patients who do not experience mortality. We refer to these observations as cure or immune and models for survival data which include cure fraction are known as cure rate models or long-term survival models. Materials and Methods: In this study we used the data collected from 438 female patients with breast cancer registered in the Cancer Research Center in Shahid Beheshti University of Medical Sciences, Tehran, Iran. The patients had been diagnosed from 1992 to 2012 and were followed up until October 2014. We had to exclude some because of incomplete information. Phone calls were made to confirm whether the patients were still alive or not. Deaths due to breast cancer were regarded as failure. To identify clinical, pathological, and biological characteristics of patients that might have had an effect on survival of the patients we used a non-mixture cure rate model; in addition, a Weibull distribution was proposed for the survival time. Analyses were performed using STATA version 14. The significance level was set at $P{\leq}0.05$. Results: A total of 75 patients (17.1%) died due to breast cancer during the study, up to the last follow-up. Numbers of metastatic lymph nodes and histologic grade were significant factors. The cure fraction was estimated to be 58%. Conclusions: When a cure fraction is not available, the analysis will be changed to standard approaches of survival analysis; however when the data indicate that the cure fraction is available, we suggest analysis of survival data via cure models.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7923-7927
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• 2015

Background: The Cox PH model is one of the most significant statistical models in studying survival of patients. But, in the case of patients with long-term survival, it may not be the most appropriate. In such cases, a cure rate model seems more suitable. The purpose of this study was to determine clinical factors associated with cure rate of patients with breast cancer. Materials and Methods: In order to find factors affecting cure rate (response), a non-mixed cure rate model with negative binomial distribution for latent variable was used. Variables selected were recurrence cancer, status for HER2, estrogen receptor (ER) and progesterone receptor (PR), size of tumor, grade of cancer, stage of cancer, type of surgery, age at the diagnosis time and number of removed positive lymph nodes. All analyses were performed using PROC MCMC processes in the SAS 9.2 program. Results: The mean (SD) age of patients was equal to 48.9 (11.1) months. For these patients, 1, 5 and 10-year survival rates were 95, 79 and 50 percent respectively. All of the mentioned variables were effective in cure fraction. Kaplan-Meier curve showed cure model's use competence. Conclusions: Unlike other variables, existence of ER and PR positivity will increase probability of cure in patients. In the present study, Weibull distribution was used for the purpose of analysing survival times. Model fitness with other distributions such as log-N and log-logistic and other distributions for latent variable is recommended.

• 한국간담췌외과학회지
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• 제26권1호
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• pp.47-57
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• 2022

Backgrounds/Aims: It is challenging to assess the efficacy of partial hepatectomy (PH) as a treatment option for patients with hepatocellular carcinoma (HCC) accompanied by cirrhosis. This study aimed to determine the cure fraction of PH for HCC accompanied by cirrhosis compared to that for HCC without cirrhosis. Methods: A systematic review was performed on outcomes of previous studies that compared recurrence-free survival (RFS) after PH in patients with HCC with or without cirrhosis. A meta-analysis was conducted to obtain the cumulative hazard ratio for two patient groups: cirrhosis and non-cirrhosis. Cure fractions after PH in both groups were determined using a cure model analysis. Results: A total of 18 studies were eligible for meta-analysis and 13 studies were selected for the cure model analysis. The cumulative hazard ratio for RFS of the cirrhosis group compared to that of the non-cirrhosis group was 1.66 (95% confidence interval [CI], 1.43-1.93). Survival data of 3,512 patients in both groups were reconstructed from survival curves of original articles for cure model analysis. The probability of being statistically cured after PH for HCC was 14.1% (95% CI, 10.6%-18.1%) in the cirrhosis group lower than that (32.5%) in the non-cirrhosis group (95% CI, 28.6%-36.4%). Conclusions: The prognosis after PH for HCC accompanied by cirrhosis is inferior to that for HCC without cirrhosis. However, a cure can be expected for one-seventh of patients with HCC accompanied by cirrhosis after PH.

• Communications for Statistical Applications and Methods
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• 제24권4호
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• pp.397-419
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• 2017

A four-parameter extended fatigue lifetime model called the odd Birnbaum-Saunders geometric distribution is proposed. This model extends the odd Birnbaum-Saunders and Birnbaum-Saunders distributions. We derive some properties of the new distribution that include expressions for the ordinary moments and generating and quantile functions. The method of maximum likelihood and a Bayesian approach are adopted to estimate the model parameters; in addition, various simulations are performed for different parameter settings and sample sizes. We propose two new models with a cure rate called the odd Birnbaum-Saunders mixture and odd Birnbaum-Saunders geometric models by assuming that the number of competing causes for the event of interest has a geometric distribution. The applicability of the new models are illustrated by means of ethylene data and melanoma data with cure fraction.

• 응용통계연구
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• 제27권1호
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• pp.21-30
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• 2014

치유율 모형(cure rate model)은 위험 그룹의 단조 감소에 대한 가정이 부적절한 경우에 적용될 수 있다. 예를 들어, 생존 분석에서 위험 그룹은 시간이 경과함에 따라 점점 감소하여 무한대의 시간대에는 영으로 수렴하며 이는 곧 생존 함수가 영으로 수렴함을 의미한다. 하지만 이러한 가정이 적합하지 못한 자료가 의약학, 사회학, 경제학 등에서 종종 발생된다. 즉, 어느 시점에 이르러 더 이상의 생존함수는 감소하지 않고 평행선을 보여주는 경우에 로그 순위검정(log rank test)과 Cox's 비례위험모형(proportional hazard model)의 적용은 바람직하지 못한 결론을 가져오게 된다. 이러한 자료에 대해 치유율 모형(cure rate model)에서는 사건 발생 취약 그룹(susceptible group)과 비취약 그룹(insusceptible group)으로 나누어 취약그룹에 대해서만 일반적인 생존 분석 방법을 적용하는 혼합 모형(mixture model)을 적용해왔다 (Berkson과 Gage, 1952). 본 연구에서는 이러한 치유율 모형을 군집화 구간 중도 절단 자료(clustered interval censored data)에 적용해 보고자 한다. 최근에 Kim과 Jhun (2008)은 구간 중도 절단자료에 대해 치유율 모형을 적용하였으며 본 연구에서는 그들의 방법을 군집화 자료로 확장할 것이다. 실제 자료 분석의 예로 금연자료를 분석할 것이다.

• Elastomers and Composites
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• 제33권5호
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• pp.315-323
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• 1998

본 연구의 목적은 카본블랙 첨가량 변화, 가황조건 및 가황시스템 변화에 따른 배합고무의 가교밀도 및 고무보강성을 조사하고자 하였다. 결합고무량은 배합고무중 카본블랙 체적비가 증가함에 따라 증가하였으나, 총가교밀도는 결합고무량 증가에 따라 감소하였다. 가황반응 속도상수는 가황온도 및 가황시스템에 따라 현저하게 변화하였으며, 특히 가황온도에 강한 의존성을 나타내었다. 가황반응의 활성화에너지는 카본블랙 첨가량이 많고 EC 가황시스템이 적용된 배합고무 또는 카본블랙 첨가량이 적고 CC 가황시스템이 적용된 배합고무에서 높게 나타났다. 가황된 배합고무중 가장 높은 총가교밀도는 카본블랙 첨가량이 적고 가황시스템중 CC 가황시스템이 적용된 배합고무에서 나타났으며, EC 가황시스템에 의한 총가교밀도의 뚜렷한 변화는 나타나지 않았다. Mooney-Rivlin식에 의한 가장 높은 탄성상수는 카본블랙 첨가량이 적고, SEC 가황시스템이 사용된 배합고무에서 나타났다. 모듈러스는 배합고무중 카본블랙 첨가량이 증가함에 따라 증가하였으며, 가황시스템별 영향은 SEC>CC>EC 시스템 순으로 높게 나타났다.

• Archives of Plastic Surgery
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• 제48권1호
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• pp.127-130
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• 2021

Rectovaginal fistula, which can arise after an injury to the vaginal canal or rectum, is a troublesome obstacle for patients' everyday life. In most cases, it can be covered with a local flap, but previous radiation therapy increases the recurrence rate, making it especially difficult to cure. As the application of stromal vascular fraction (SVF) obtained from enzymatically digested autologous adipose tissue has become increasingly common, several reports have advocated its effectiveness for the treatment of refractory wounds. In light of the angiogenic, regenerative characteristics of SVF, it was incorporated as a treatment option in two cases of rectovaginal fistula discussed here. As described in this report, irradiated rectovaginal fistulas in rectal cancer patients were successfully treated with SVF injection, and we suggest SVF as a feasible treatment option for cases of rectovaginal fistula that would otherwise be very difficult to cure.

• 대한한방내과학회지
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• 제22권3호
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• pp.353-360
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• 2001

Objectives: Recently, it was known that the major cause of hepatitis is apoptosis reaction mediated by Fas-FasL. Since Artemisia Capillaris Fructus has long been applied to cure the jaundice in oriental medicine. Therefore, this study was carried out to examine the effect of fractions of Artemisia Capillaris Fructus on Fas-FasL-mediated apoptosis in hepatocytes. Methods: This study employed propidium iodide negative cell count assay and some the other biochemical assays. Results : This study confirms that hepatitis has been occured by apoptosis mediated by Fas-FasL in cultured hepatocyte and fractions of Artemisia Capillaris Fructus restrain apoptosis induced Fas-FasL. Conclusions : Water-extracted fraction, methanol extracts, ether-soluble fraction, and buthanol-soluble fractions of Artemisia Capillaris Fructus restrain Fas-FasL-mediated apoptosis in hepatocyte. Silica gel chromatograph of Buthanol-soluble fraction of Artemisia Capillaris Fructus restrain Fas-FasL-mediated apoptosis in hepatocyte. Artemisia Capillaris Fructus could be applied to cure hepatitis.

• 응용통계연구
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• 제17권2호
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• pp.253-267
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• 2004

임상시험중에는 소아암연구에서와 같이 환자 중의 상당수에서 사망 또는 재발이 오랜 기간 일어나지 않고 완치된 것으로 보이는 경우가 있다. 이 경우 연구자는 생존함수의 전반적인 비교보다는 치료율의 비교에 더 관심이 있을 것이다. 본고에서는 치료율의 비교를 위한 여러 모수적, 비모수적 방법들을 소개하고, 생존분포, 치료율, 중도절단을 등을 다양하게 설정한 모의실험을 통하여 각 방법들의 검정력과 유의수준을 비교하였다.

• Communications for Statistical Applications and Methods
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• 제24권6호
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• pp.605-625
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• 2017

This paper presents proportional odds cure models to allow spatial correlations by including spatial frailty in the interval censored data setting. Parametric cure rate models with independent and dependent spatial frailties are proposed and compared. Our approach enables different underlying activation mechanisms that lead to the event of interest; in addition, the number of competing causes which may be responsible for the occurrence of the event of interest follows a Geometric distribution. Markov chain Monte Carlo method is used in a Bayesian framework for inferential purposes. For model comparison some Bayesian criteria were used. An influence diagnostic analysis was conducted to detect possible influential or extreme observations that may cause distortions on the results of the analysis. Finally, the proposed models are applied for the analysis of a real data set on smoking cessation. The results of the application show that the parametric cure model with frailties under the first activation scheme has better findings.