Thymoma, type A, NOS: A National Cancer Database study of demographic and socioeconomic factors.

Abstract

e20170 Background: Type A Thymoma (TAT), not otherwise specified (NOS), is a rare, indolent thymic epithelial tumor composed of spindle-shaped cells with few or no immature lymphocytes. This subtype of thymoma generally carries a favorable prognosis with excellent long-term survival rates, given the low risk of metastasis or recurrence following complete surgical resection of the encapsulated tumor. This study aims to use the National Cancer Database (NCDB) to analyze the demographic and socioeconomic factors in patients with a confirmed diagnosis of TAT NOS since current data relies on smaller institutional case series and cohorts as well as the broader limitation of epidemiological data. Methods: A retrospective cohort analysis using the 2004–2020 NCDB included 926 patients with a histologically-confirmed diagnosis of TAT, NOS ICD-O-3 code (8581). Demographic factors (age, sex, race, Hispanic status, educational attainment, insurance status, facility type, distance from facility, and Charlson-Deyo score) were analyzed using descriptive statistics, and incidence trends were interpreted through regression analysis. Results: The incidence rate of new diagnoses remained relatively stable over 2004-2020 (R^2 =0.59). Men (51.9%) were most likely to be diagnosed and average age at diagnosis was 67.1 years (SD = 12.2, range 15 – 90 years). The common primary site was the thymus (99.6%). The majority of this cohort were White (77.8%), Non-Hispanic (89.3%), and lived in metropolitan areas (86.7%). Patients were treated in an academic/ research program (39.6%) or a comprehensive community cancer program (36.3%), located in the Middle Atlantic (22.1%) or the South Atlantic (21.1%). In most cases, patients were insured by Medicare (56.5%) or privately insured (32.6%) and had no comorbidities (71.4%, Charlson-Deyo = 0). The common treatment was a surgical procedure of the primary site (84.8%) with most cases undergoing a complete thymectomy (40.5%), followed by radiology (32.6%) or chemotherapy (11.2%) as the primary treatment. A minority of patients received palliative care (1.5%). Long-term survival at two, five, and ten years was 98%, 95%, and 90% respectively. Conclusions: To our knowledge, no prior NCDB analysis has investigated TAT NOS, and this work fills an important knowledge gap in this area. Consistent with previous research, TAT NOS most commonly affected Non-Hispanic (89.3%), White patients, with tumors predominantly being found in the thymus. Socioeconomic characteristics of the cohort included the majority living in metropolitan areas and treated at an academic/research center. Additional studies are needed to understand the associations between demographic and socioeconomic factors of TAT NOS diagnosis, treatment approaches, and survival outcomes.