Abstract
e18099 Background: CASTLE, or Thyroid Carcinoma Showing Thymus-Like Elements, is an indolent and uncommon cancer that is believed to originate from either ectopic thymus tissue or remnants from the branchial pouches and affects the thyroid gland. It makes up a small portion, less than 0.1 - 0.15%, of all thyroid carcinomas and tends to affect slightly more females than males. Due to the lack of literature on this malignancy, understanding the trend in its diagnoses can provide valuable information about its epidemiology. The demographic factors of patients diagnosed with CASTLE were analyzed using data from the National Cancer Database (NCDB). Methods: A study was conducted using the NCDB from 2004 – 2020 to examine patients diagnosed with CASTLE (N = 23). Demographic factors such as age, sex, race, Hispanic ethnicity, education level, insurance coverage, type of medical facility, distance from the facility, and Charleson-Deyo score were analyzed using descriptive statistics. Trends in the incidence of the disease were analyzed through regression analysis. Results: The National Cancer Database was analyzed and revealed that 23 patients were diagnosed with CASTLE between the years 2004 to 2020, with a stable incidence rate per year (R2 = 0.1). The average age of diagnosis was 61.0 years (SD = 14.3, range = 31 – 87). The average Charlson-Deyo comorbidity score was 0.5, with 0 being the most common score (69.6%). The majority of patients (87.0%) were non-Hispanic and White. Most patients were found to be in the top two income quartiles (60.8%) earning more than $57,857 per year. A larger portion of patients had private insurance coverage (60.9%) compared to those who were uninsured or covered by Medicare/Medicaid. A greater number of patients lived in metropolitan counties with a population over 1 million (47.8%) than in other metropolitan counties (43.5%). Patients were more likely to receive treatment in a non-academic program (63.6%) such as community cancer programs, comprehensive community cancer programs, or integrated network cancer programs. On average, patients lived 11.4 miles (SD = 11.1, range = 0.7 – 46.7) from the treatment facility. Conclusions: This is the first analysis of CASTLE in the National Cancer Database, filling a significant gap in knowledge on the subject, particularly regarding the socioeconomic characteristics of CASTLE patients. The average CASTLE patient is a 60-year-old White, non-Hispanic male. These patients are more likely to be upper-middle-class citizens, have private insurance, live in densely populated metropolitan areas, and receive treatment at comprehensive community cancer programs. Further investigation is necessary to explore the statistical correlation between demographic and socioeconomic variables and the diagnosis, treatment, and outcomes of CASTLE patients.