Abstract
To study which factors increase the risk of persistent disease in differentiated and poorly differentiated thyroid carcinoma. Methods: A retrospective chart review of all consecutive differentiated and poorly differentiated thyroid cancer patients from King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia, a tertiary care center, between 2004 and 2018. Logistic regression analysis was performed to predict factors associated with less than excellent response to treatment. Results: We included 186 patients with complete data records; 81.1% were females. Papillary thyroid carcinoma comprised 88.1% of the neoplasms. In total, 55.9% of patients attained an excellent response to treatment by the end of the first year following treatment. All patients with distant metastasis had persistent disease. On univariate analysis, female gender was associated with excellent response (p=0.002). Lymph node metastasis, extrathyroidal extension, vascular invasion, and cancer multifocality were all found to be inversely related to excellent response (p less than 0.05 for all). On multivariate analysis only lymph node metastasis was associated with a decreased adjusted odds of an excellent response (p=0.007). Conclusion: Patients with lymph node metastasis are at high risk for persistent disease following initial thyroid cancer management. Careful monitoring of these patients is warranted.