Assessment of affecting risk factor on relapse and death in patients with thyroid cancer in Khorasan Razavi 2005-2015

Background and Aim: Thyroid cancer is one of the most common endocrine system cancer and rare types of cancers. However, despite to low death rate, the prevalence of this disease is high. Different factors affected on incident, recurrence and death in thyroid cancer patients. This study aimed to identify these factors. Method: In this historical cohort study, 631 cases of thyroid cancer referred to Imam Reza, Ghaem and Sina hospitals were assessed. The effect of various demographic and clinical factors on survival and relapse of patients was evaluated using parametric and semi parametric model analysis. Data were analyzed using of R software. Result: Most of patients are females (74.8%). The mean (SD) age of the diagnosis was 39.74(15.71). 17 patients (2.7%) experienced death and 140 patients had recurrence (22.2%). In multivariate analysis with recurrent event, age of diagnosis, tumor sizes are significant in semi parametric model, and age of diagnosis, tumor size, and distant metastases are significant in parametric model. In multivariate analysis with death event, age of diagnosis and weight groups in semi parametric model are significant, and age of diagnosis and gender are significant in parametric model (p<0.05). Conclusion: Many of the results of this study are consistent with results of previous studies, but different risk factors in various studies are due to the fact that the effects of the predictive factors can change from one society to another.