Survival and relapse of Danish patients with thymic epithelial tumors

BACKGROUND AND PURPOSE: This study aims to evaluate survival, relapse, comorbidities, and prognostic factors in patients with thymic epithelial tumours (TETs) to improve risk stratification for TET-related mortality and relapse and support evidence-based follow-up and treatment strategies. Patient/material and methods: The cohort consists of consecutive Danish patients diagnosed with thymoma, thymic carcinoma (TC), or thymic neuroendocrine tumor (NET) between January 1st, 2015 and December 31st, 2020, with follow-up data available. Data were collected from online medical records including disease characteristics, survival outcomes, comorbidities, and relapse. Statistical analyses were performed in R 4.3.2 and the prognostic value baseline traits were analyzed using Cox Proportional Hazards models. RESULTS: Our cohort comprised 282 patients with a mean diagnostic age of 65 years and the following histological distribution: thymoma (85%), TC (13.6%), and NET (1.4%). During the 72-month mean follow-up, 65 deaths occurred yielding overall survival (OS) of 81% in patients with thymoma and 47% in patients with TC. TET-related deaths predominated in TC, yielding a cancer-specific survival) of 53% compared with 96% in thymoma. Reduced OS was associated with increasing age (p < 0.001) and advanced Tumor, Node, Metastasis-stage (III p < 0.05; IV p < 0.001). Disease progression was verified in 13/201 (6%) of thymoma patients with R0 or R1 resection. INTERPRETATION: We report a high OS of Danish TET patients compared to existing population-based studies. The occurrence of TET-related mortality and disease progression in patients with thymoma and TC, highlights the need for long-term follow-up and therefore risk stratification in TET management.