Abstract
OBJECTIVE: Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis, represents the most prevalent autoimmune thyroid disorder globally. The potential influence of HT on the clinical and pathological attributes, as well as the clinical outcomes of differentiated thyroid carcinoma (DTC), remains a point of ongoing debate within the medical community. The central focus of this study was to analyze the influence of HT on clinico-pathological characteristics and its prognostic impact in a large cohort of DTC from Middle Eastern ethnicity. Design, Patients, Measurements. An extensive analysis involving 1822 DTC patients was conducted to determine the association with clinico-pathological characteristics as well as prognosis, using Chi-square tests and Kaplan-Meier curves. RESULTS: 23.9% (435/1822) of DTC patients were diagnosed with HT. Univariate analysis revealed a positive correlation between presence of HT and clinico-pathological factors such as female gender, younger age, and early stage tumor. In contrast, HT demonstrated a negative association with several aggressive clinical features, including extrathyroidal extension, distant metastasis, recurrent/persistent disease and high-risk categorization by the American Thyroid Association (ATA) guidelines. Despite HT being associated with favorable clinico-pathological features in Middle Eastern DTC patient, our study found no significant influence on overall survival or recurrence-free survival. CONCLUSION: The finding of an association between HT and favorable clinico-pathological characteristics, but lack of impact on prognosis, underscores the complexity of HT-DTC relationship, necessitating further comprehensive research to fully understand these interactions.