Narges Ghorbani - Department of Biostatistics, School of Public Health, AND Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Jamshid Yazdani Charati - Department of Biostatistics, School of Public Health AND Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran
Kazem Anvari - School of Medicine, Cancer Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

Introduction & aim: The estimated risk of death in patients with primary breast cancer by taking on the risk of recurrent metastatic events simultaneously is being intended in the joint survival model. Method: Based on the cohort study, the patients were followed for 8 years. The depended variable was determined gap times between recurrent events. The estimates, under the joint model of recurrent events risk and death of the patient with spline functions, were determined. The analysis was done with R software. Result: the age average of the patients was 49±11 years. The median age 47 years with age minimum 25 years and maximum age 80 years were reported.Among of the patients 20.2 percent ( 84),43.3 percent ( 180), 36.5 percent (152) were respectively deceased, alive and unknown life status The certainly overall survival and uncertainly overall survival was estimated 0.41 and 0.49 respectively.The simultaneous risk of recurrent event and death were increased respectively, for variables, size of tumor (RR=1.44, RR=1.10), level of cea before first recurrence (RR=12.06, RR= 1.63), level of ca15-3 before first recurrence (RR=12.42, RR=3.2), involved lymph nodes (RR=5.54, RR=2.56), local recurrence (RR=11.30, RR=3.48) and were decreased for hormonal (radio) therapy ( RR=0.06, RR=0.67), the MRM surgery was decreased the risk of death ( RR= 0.23) but it do not have any significant effect on the risk of recurrent metastatic simultaneously. Conclusion: Under consideration the all of the medicine events (such as recurrence, death,etc..)simultaneously and defining the sophisticated survival models, attain the best accurate results.

joint modeling, breast neoplasm