Follicular thyroid cancer (FTC) is a common endocrine malignancy that is mainly treated with surgical resection. Few prior studies have investigated the optimal type of surgery for this FTC, particularly at a national registry level. The aim of this study is to examine the differences between surgical subtypes in the management of FTC.
Patients from the Surveillance, Epidemiology, and End Results (SEER) database who were diagnosed with FTC between 2000-2020 were selected. The surgeries were categorized into sublobectomy, lobectomy, subtotal thyroidectomy, or thyroidectomy groups based on the surgical procedure performed. Additional variables were collected including age, sex, race, stage, radiation status, time to treatment, household income, and population size. Kaplan-Meier, Chi-square and logistic regression analyses were performed.
A total of 9,983 patients were included. Using Kaplan-Meier, there was improved survival for patients that received surgery (p<0.001). Patients who underwent lobectomy had greater survival than all groups (p<0.001) while thyroidectomy had greater survival compared to sub-lobectomy (p=0.015). On Chi-square, differences at one- and five-year survival were present between surgical groups (p=0.022 and p<0.001, respectively). However, logistic regression showed no survival difference between surgery type at one- and five-years. Additional findings include regional and distal staging having worse survival at one- and five-years (p’s<0.001) while median household income >$75,000 and receipt of radiation improved survival at one-year (p’s<0.05). Household income >$75,000 and radiation status no longer improved survival at five-years. Patients living outside metropolitan areas showed an improved survival at fiveyears (p=0.036).
The results of the preliminary Kaplan- Meier and Chi-square analysis showed that there are significant differences in survival between different surgery subtypes. However, after controlling for multiple variables, no survival differences were observed between surgical types. Despite minimal differences in FTC survival based on the type of surgical intervention, clinical factors like stage and radiation and socioeconomic factors like household income and population size may influence FTC survival. Identifying and controlling for these variables should be considered in future research on FTC.