Overall survival trends of papillary thyroid cancer: A Surveillance, Epidemiology, and End Results (SEER) population-based data (2002-2016).

Abstract

e18108 Background: In the United States, the 5-year survival rate for patients with thyroid cancer is 98%. However, survival rates are mainly influenced by the type of thyroid cancer and the stage of the disease. The tremendous research in the area and the need to assess outcomes of recently implemented treatments necessitate the evaluation of the epidemiology and overall survival rates of the most common type of this malignancy, papillary thyroid cancer (PTC). Although the cause-specific survival (CSS) of Papillary Thyroid Cancer (PTC) patients has been extensively investigated, the overall survival (OS) of these patients is unclear. In this study, we aim to conduct an evaluation of survival trends after PTC diagnosis by stage of disease for the years 2002 through 2016 in the United States. Methods: We used the SEER 9 database to study PTC cases during 2002-2016. The patient survival data for the three disease stages (local, regional, and distal) were compared for the two time periods of interest, (2002-2008) and (2009-2016). The data for each cohort were split into six groups, (those whose deaths were in each of the five one-year intervals and those surviving the five-year follow-up period). These categorical counts were compared by the chi-square test of contingency table data. Statistical significance was taken as a p-value less than 0.05. Results: We reviewed 73,333 PTC cases in the United States from 2002 through 2016. There was an overall survival improvement with the exception of the distal stage, which did not demonstrate any statistical difference in the 2-time frames of interest. For local sites, there was a highly significant difference between the survival distributions of patients in the two time periods of interest (p = 0.0095; chi-square test statistic = 15.20 with 5 degrees of freedom). For regional sites, there was a highly significant difference between the survival distributions of patients in the two time periods of interest (p = 0.0077; chi-square test statistic = 15.72 with 5 degrees of freedom). For the distant stage, there was no significant difference between the survival distributions of patients in the two time periods of interest (p = 0.28; chi-square test statistic = 6.25 with 5 degrees of freedom). Conclusions: PTC’s survival rates have shown an improvement over the years 2002 through 2016, mostly noted in the local and regional stages. Although most patients with PTC have a favorable prognosis when conventional treatments are implemented, local recurrence and distant metastasis of advanced PTCs still hamper the survival and clinical management in certain patients.