A tumor, node, metastases (TNM)-based stage classification system of thymic epithelial tumors was adopted for the 8 edition of the stage classification of malignant tumors. The Thymic Domain of the Staging and Prognostics Factor Committee of the International Association for the Study of Lung Cancer developed a new database with the purpose to make proposals for the 9th edition stage classification system. This article outlines the proposed definitions for the T categories for the 9 Ed. TNM stage classification of thymic malignancies.
A worldwide collective database of 11,347 patients with thymic epithelial tumors was assembled. Analysis was performed on 9,147 patients with available survival data. Overall survival, freedom-from-recurrence and cumulative incidence of recurrence were used as outcome measures. Analysis was performed separately for thymomas, thymic carcinomas and neuroendocrine thymic tumors.
Proposals for the T categories include: T1 category is divided into T1a (≤5cm) and T1b (>5cm) irrespective of mediastinal pleura invasion; T2 includes direct invasion of pericardium, lung or phrenic nerve; T3 denotes direct invasion of the brachiocephalic vein, superior vena cava, chest wall, or extrapericardial pulmonary arteries and veins; and T4 category remains the same as in the 8 Ed. classification, involving direct invasion of the aorta and arch vessels, intrapericardial pulmonary arteries and veins, myocardium, trachea, or esophagus.
The proposed T categories for the 9 edition of the TNM classification provide good discrimination in outcome for the T component of the TNM-based stage system of thymic epithelial tumors.
Copyright © 2023. Published by Elsevier Inc.
