Determination of Multiple Recurrences after Breast Surgery using a Random Effect Model

The aim of this study was to determine multiple recurrences after breast surgery using a random effect model. This is a cohort study in which 342 patients were evaluated after breast surgery during the period 2015 to 2020. All information of breast cancer patients was extracted from their files and their recurrence rate was evaluated and predicted based on the fragility model. The risk of multiple local recurrences and metastases increases in people under 40 years of age compared to people over 55 years of age. Also, tumor size (more than 20 mm) has a significant effect on the risk of local recurrence and metastasis in patients. In addition, patients with HER2 + have a higher risk of multiple local recurrences and metastases. The correlation between multiple local recurrences and metastasis in these patients was 0.79 in the combined model. Also, the values of fragility variance for local recurrence and metastasis were 1.1 and 7.39, respectively. The results of this study showed that patients with the same explanatory variables have different risk of metastasis. Also, the relationship between two types of metastatic and local recurrences was high in patients with breast cancer, which is of great importance in the process of diagnosis and treatment of this disease.