Survival and relapse of Danish patients with thymic epithelial tumors

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.

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.

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.