The Prognostic Role of the Number of Involved Structures in Thymic Epithelial Tumors: Results from the ESTS Database

The role of the number of involved structures (NIS) in thymic epithelial tumors (TETs) has been investigated for inclusion in future staging systems, but large cohort results still are missing. This study aimed to analyze the prognostic role of NIS for patients included in the European Society of Thoracic Surgeons (ESTS) thymic database who underwent surgical resection. Clinical and pathologic data of patients from the ESTS thymic database who underwent surgery for TET from January 2000 to July 2019 with infiltration of surrounding structures were reviewed and analyzed. Patients’ clinical data, tumor characteristics, and NIS were collected and correlated with CSS using Kaplan–Meier curves. The log-rank test was used to assess differences between subgroups. A multivariable model was built using logistic regression analysis. The final analysis was performed on 303 patients. Histology showed thymoma for 216 patients (71.3