Next revision of the T descriptors in the TNM classification for thymic epithelial tumors: possibilities and problems

The TNM classification of cancers proposed by the Union for International Cancer Control (UICC) is a widely accepted guide for predicting prognoses, selecting therapy and facilitating the development of new treatment strategies. In 2016, the UICC and American Joint Committee on Cancer (AJCC) applied the TNM cancer staging system to thymic epithelial tumors (1). In this edition, the International Association for the Study of Lung Cancer (IASLC) and the International Thymic Malignancies Interest Group (ITMIG) staging committee proposed the classification (2-4).