The differences in distant metastatic patterns and their corresponding survival between thyroid cancer subtypes.

Introduction: This study aimed to systematically elucidate the metastatic patterns and their corresponding survival of each thyroid cancer subtype at time of diagnosis. Methods: We accessed the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2018 to search for primary thyroid cancers with DM at presentation (M1). Results: We included 2787 M1 thyroid cancers for statistical analyses and the incidence of DM at presentation was 2.4%. Lung was the most common metastatic site for anaplastic thyroid carcinoma (ATC), poorly differentiated thyroid carcinoma (PDTC), papillary thyroid carcinoma (PTC), and oncocytic (Hurthle) cell carcinoma (HCC) whereas bone is the favorable disseminated site of follicular thyroid carcinoma (FTC) and medullary thyroid carcinoma (MTC). Patients with multi‐organ metastases had the worst survival whereas bone metastases were associated with a favorable outcome (p < 0.001). Conclusion: There are significant differences in DM patterns of thyroid cancer subtypes and their corresponding survival. [ABSTRACT FROM AUTHOR]