The International Association for the Study of Lung Cancer Thymic Tumors Staging Project: The Impact of the Eighth Edition of the Union for International Cancer Control and American Joint Committee on Cancer TNM Stage Classification of Thymic Tumors

Abstract

Objectives: The International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee-Thymic Domain conducted a web-based cross-sectional survey to assess the acceptance of the TNM thymic staging system in the thoracic community.Methods: A 50-item, web-based questionnaire was circulated among the members of the major thymic organizations worldwide from September to December 2018. The survey consisted of six sections (general information; overall perception of the TNM system; pretreatment staging; T category; N category; and perioperative treatments).Results: In total, 217 responses were collected from 37 countries in four continents. The TNM classification was considered useful by 78% of the responders (N ¼ 169); the Masaoka-Koga staging system was being used by 87% of the responders (N ¼ 189). With regard to the T category, most responders (mostly surgeons) felt that the capsular and mediastinal pleural involvements should be considered separate T categories. As for the N category, 48% of the responders (N ¼ 105) used the International Thymic Malignancies Interest Group/International Association for the Study of Lung Cancer thymic nodal map, and lymph node dissection (N1/N2) was performed for 50%/21% thymomas and 66%/41% thymic carcinomas. While analyzing the results by the three continents (Europe, Asia, and Americas), responders in Asia were found to report the largest use of the TNM system, the greatest attention to the N category, and the best participation in international thymic databases. Conclusions:The survey indicates that the Union for International Cancer Control/American Joint Committee on Cancer TNM stage classification of thymic tumors is gaining acceptance among the scientific community. The present results will guide the work of the Staging and Prognostic Factors Committee-Thymic Domain for the revision of the ninth edition of the TNM stage classification of thymic tumors.

Primary Driver Mutations in GTF2I Specific to the Development of Thymomas

“…Thymomas comprise tumor and normal cells. In particular, type B thymomas consist of a significant proportion of lymphocytes [ 15 , 16 ]. Contamination with normal cells reduces the probability of detecting mutations in tumor cells.…”

“…We obtained written informed consent for genetic research from all the patients in accordance with the protocols approved by the Institutional Review Board at our hospital (Institutional Review Board at Yamanashi Central Hospital). The specimens were categorized histologically based on the classification guidelines by the World Health Organization [ 16 , 27 ], and staged according to the Masaoka staging system [ 7 , 15 , 28 ]. Sections of formalin-fixed and paraffin-embedded tissues were stained with hematoxylin-eosin and microdissected using the ArcturusXT laser-capture microdissection system (Thermo Fisher Scientific, Waltham, MA, USA).…”

Correlation of Computed Tomography Parameters with Histology, Stage and Prognosis in Surgically Treated Thymomas

“…Although long-term survival may be observed after complete surgical treatment, up to 50% of the tumors recur during follow-up [10]. Hence, several studies tried to identify pathological [11], radiological [9] and bio-humoral [12] features able to predict the risk of relapse after surgical treatment. Differentiated approaches in terms of extent of surgical resection and nodal dissection according to tumor stage and histology have been suggested [13], and therefore an accurate preoperative assessment is mandatory to correctly define the surgical strategy.…”

“…This is due to the fact that the current TNM staging system does not differentiate between encapsulated tumors and tumors invading the thymic tissue or mediastinal fat, all classified in stage I. However, it is noteworthy that a recent survey carried out in high-volume thymic-specialized European, American and Asian centers [11] showed that capsular infiltration may still play a prognostic role, and this issue should be specifically dealt with in the definition of the ninth edition of TNM staging system.…”

Thymic Epithelial Tumors as a Model of Networking: Development of a Synergistic Strategy for Clinical and Translational Research Purposes

“…We provide blocks with "key-blocks" in order to evaluate the tumor and its surrounding tissue for accurate staging (37). Anterior mediastinal lymph nodes are also included in the sampling, because they are usually removed by the surgeons together with the fat tissue of the anterior mediastinum (52). In surgically treated THY cases at IRE, we found a metastasis in only one case, in a laterocervical lymph node (53), which developed 9 years from the original diagnosis.…”