Changes of Clinicopathologic Characteristics and Survival Outcomes of Anaplastic and Poorly Differentiated Thyroid Carcinoma

Background: This study aimed to analyze the temporal changes of the clinicopathologic characteristics, and the long-term outcomes, of various types of anaplastic thyroid cancer (ATC) and poorly differentiated thyroid cancer (PDTC). Methods: A retrospective analysis was conducted on patients with ATC and PDTC who were treated from 1985 to 2013. The outcome measures included the clinical response to treatment and the survival rates of three separate thyroid cancer groups: ATC, PDTC, and differentiated thyroid cancer (DTC) with anaplastic foci. Results: The five-year disease-specific survival rate was significantly higher, both in DTC with anaplastic foci and in PTDC (81.3% and 65.8%, respectively), than it was in ATC (14.3%; p