The study of prognostic factors of survival in patients with breast cancer referred to cancer research center

Parviz Shahmirzalou,1,*

1. Department of Biostatistics, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran



Breast cancer is a malignant tumor that starts from cells of the breast and is seen mainly in women. it’s the most common cancer in women worldwide and is a threat to their health. the purpose of this study is to fit cox proportional hazards model for prediction of survival and determining the years of survival in patients.


The 366 patients with breast cancer in cancer research center were included in the study, then cox proportional hazard model were used with variables such as tumor grade, number of removed positive lymph node, human epidermal growth factor receptor 2(her2) and several other variables. kaplan-meier curves were plotted and multi-year of survival was evaluated.


The mean age of patients was estimated to 48.13 years old. variable for consumption of fatty foods (p=0.033), recurrence (p<0.001), tumor grade (p=0.046) and age (p=0.017) were significant. the overall 1- year, 3-year and 5-year survival rate was found as 93%, 75% and 52%.


The presence of covariates and using the cox proportional hazard model are effective in predicting the survival of the individual and this model distinguished 4 effective factors in the survival of patients.


Breast neoplasms, cox model, proportional hazards models, survival analysis