NCDB analysis of follicular adenocarcinoma, well-differentiated: Demographic and clinical outcomes.

Abstract

e18134 Background: Follicular adenocarcinoma, well differentiated (FAWD), is a slow-growing cancer that originates in the follicular cells of the thyroid gland and typically has a favorable prognosis, with over 92.3% of patients surviving 5 years after diagnosis. However, a subset of cases may exhibit aggressive behavior, including vascular or capsular invasion and distant metastases. Standard management involves surgical thyroidectomy, sometimes followed by radioactive iodine ablation. Because this malignancy is rare, population-level epidemiological data are limited, and a comprehensive analysis using data from a national cancer registry could help clarify how demographic and clinical factors relate to disease risk and treatment outcomes. Methods: This study employed a retrospective cohort design using the National Cancer Database (NCDB) from 2004 to 2020, encompassing 999 patients with histologically verified FAWD diagnoses (ICD-O-3 Code 8331). The analysis examined demographic characteristics (age, sex, race, Hispanic ethnicity, education, insurance coverage, treatment facility type, travel distance to facility, and Charlson-Deyo comorbidity scores) via descriptive statistics. Incidence patterns were evaluated using regression analysis. Results: A total of 999 patients were identified, demonstrating a stable incidence across the period (R^2 = 0.019). The mean age at diagnosis was 50.3 years, and the mean tumor size was 36.7 mm. The cohort was predominantly female (71.8%), White (78.7%), and non-Hispanic (87.5%). 42.3% patients resided in the highest socioeconomic strata (≥ $74,063), and the majority were insured by private carriers (61.5%). Surgical resection was the primary therapeutic modality (92.3%), with 88.0% of those cases achieving negative margins. Total thyroidectomy (65.4%) was the most common surgical procedure. Primary radiation treatment was utilized by 59.8% of the cohort, while chemotherapy and immunotherapy were rare (<1%). The mean overall survival was 183.21 months, and the 2-year, 5-year, and 10-year survival rates were 96.9%, 92.3%, and 85.8%, respectively. Conclusions: To our knowledge, this is the first comprehensive NCDB analysis characterizing FAWD. Findings show that FAWD patients are predominantly White, non-Hispanic females with low comorbidity and early-stage disease, aligning with the known association between higher socioeconomic status and well-differentiated thyroid cancer. They were also more likely to belong to the highest socioeconomic strata and receive care in academic or comprehensive community centers. The high rate of R0 resections and favorable 10-year overall survival suggest an excellent prognosis. Further research is needed to clarify how demographic and socioeconomic factors influence outcomes.