Abstract
e18103 Background: Nonencapsulated sclerosing carcinoma (NSC) is a rare and aggressive variant of papillary thyroid carcinoma (PTC) that accounts for 0.7-6.6% of its cases. It is associated with greater rates of vascular invasion, metastasis, and relapse compared to classic PTC. With prompt initiation of aggressive treatment including radical surgery, lymph node resection, and possible radioiodine treatment, NSC has a 10-year survival rate of 93%. Given the importance of proper diagnosis and selection of aggressive treatments, data regarding its epidemiology could further improve patient outcomes. The demographics of NSC patients were analyzed using the National Cancer Database (NCBD). Methods: Data from NCDB was queried and patients with a confirmed diagnosis of NSC between 2004 and 2020 were identified for a retrospective cohort analysis (N = 1,130). Yearly diagnosis rates were analyzed using regression analysis. Factors including patient age, sex, race, insurance status, urban/rural residence, surgical treatment approach, treatment facility type, and 90-day mortality were identified and evaluated via descriptive statistics. Results: The NCDB contained a total of 1,130 patients with a confirmed diagnosis of NSC from 2004 – 2020. The incidence rate of new diagnoses remained stable over this time (R2 = 0.0). Women were much more likely to be diagnosed (78.5%) compared to men (21.5%) with an average age at diagnosis of 44.0 years (SD = 18.7, range = 6 – 90 years). Most patients were White (86.0%), lived in metropolitan areas with a greater than 1 million population (56.5%), and were privately insured (68.9%). The vast majority of patients were treated surgically (99.9%). A complete thyroidectomy was the most common surgical approach (89.3%), more so than subtotal thyroidectomy or lobectomy. For the patients with valid data, the most common treatment facility type was an academic/research program (42.6%) followed by comprehensive community cancer programs (33.8%). Most patients survived at least ninety days after their primary surgery (98.2%) and were still alive at the date of last contact (88.4%). Conclusions: NSC is an aggressive subtype of PTC, but it generally has a good prognosis with initiation of aggressive treatment. The findings of this research corroborated previous studies showing that NSC is much more common in females than males, is most commonly treated with complete thyroidectomy, and has high 90-day survival rates. In examining the demographic features of this patient population, it was found that the majority of patients were White, lived in large metropolitan areas, and were privately insured. This may suggest that a relative ease of access to healthcare aided in their diagnosis. Future research should focus on understanding how demographic and socioeconomic factors may contribute to the timing of diagnosis, chosen treatments, and overall mortality rates of patients with NSC.