Basic & Clinical Cancer Research 2017. 9(1):4-11.

Determining of the Effecting Factors on the Survival Time of Colorectal Cancer Patients Based on a Generalized Weibull Competing Risks Model
Soraya Moamer, Ahmad Reza Baghestani, Mohamad Amin Pourhoseingholi, Ali Akbar Khaden Maboudi, Seyed Hossein Seyed Agha, Mohammad Reza Zali


Background and Objective: One of the main reasons of death around the world is Colorectal cancer. The incidence of this cancer has increased in recent years. The aim of this study was to evaluate the survival rate and to define the prognostic factors in Iranian colorectal cancer patients using parametric competing risk model. 

Materials and Methods: Data recorded from 1060 patients with colorectal cancer who registered in Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences (Tehran, Iran) from 2004 to 2015 in a retrospective study. Analysis was performed using competing risks model and based on the generalized Weibull distribution. Data analysis was carried out using R software and significance level was regarded as 0.05.

Results: At the end of follow-up, 380 (35.8%) patients died due to colorectal cancer, 49 (4.6%) patients due to other diseases and 631 (59.5%) patients survived until the end of the study. The mean survival time in studied patients was 56.96±1.46 months with median 45.5 months. According to competing-risks method, only age at diagnosis and body mass index has a significant effect on patient’s survival time.

 Conclusion: Based on parametric competing risk model, just age at diagnosis and body mass index were significant prognosis of colorectal cancer survival.



Survival Analysis, Competing risk, Colorectal cancer, Weibull model

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