Journal of North Khorasan

Abstract Background & Objectives: The analysis of age and survival probabilities, today, is several decades old. The calculation of age average in different groups of human society and analysis of factors which are effective on it to access methods for increase of individual’s health and age is one the daily concerns of scientists in different branches of biology and medicine. The objectives of this study were to assess the effects of prognostic factors on survival of patients with breast cancer using the Aalen additive hazards model, and to illustrate the advantage of Aalen’s plot. Materials & Methods: during 2005-2007, 133 women with breast cancer were treated in Fayazbakhsh hospital, Tehran. All patients followed until 2011 April. To analysis data, Aalen's additive hazard model used. The graph of estimated cumulative regression function (Aalen s graph) was draw to analyze the effect of independent variable during time. Results: Significant factors in univariate analysis was entered into multivariable analysis of Allen`s additive hazard model. HER2, third tumor malignancy grade and the number of positive lymph nodes more than 10 were recognized as significant factors in patient`s survival in multivariable model. Conclusion: Additive hazard model is used as a suitable substitution for Cox model. In which standard deviation of estimations will be smaller than Cox model.