Revisions to the global tumor TNM staging classification criteria for lung cancer, mesothelioma, and thymic cancer may still be in the final stages of preparation, but WCLC attendees will get a preview of the 9th Edition TNM Staging Classification during a special plenary session dedicated to the proposed updates. The 9th Edition is set to be published jointly by IASLC, the Union for International Cancer Control, and the American Joint Committee on Cancer in early 2024. Staging criteria were last updated in 2017.
“There will be small but important changes to the TNM rules for lung cancer,” said Hisao Asamura, MD, Chair of the IASLC Staging and Prognostic Factors Committee. “We now have broader possibilities of treatment than we had in 2017, especially for metastatic disease with the addition of molecular targeted therapy and immunotherapy. We will have important new subcategories to M1 disease based on the total tumor burden, which will help us refine treatment challenges.”
Dr. Asamura is Professor and Chief of Thoracic Surgery, Keio University School of Medicine, Tokyo, Japan. He will discuss the changes coming to lung cancer staging classification during “Special Plenary Session 4: TNM for Lung, Mesothelioma and Thymic Cancers—Update on the Proposals for the 9th Edition of TNM Staging,” which will take place from 17:00-18:00 on Monday, September 11, room 406 at at the Suntec Singapore Convention & Exhibition Center. The session will be livestreamed and available on-demand for virtual attendees.
Special Plenary Session 4: TNM for Lung, Mesothelioma and Thymic Cancers—Update on the Proposals for the 9th Edition of TNM Staging
17:00–18:00 SGT, Monday, September 11, Room 406
The IASLC has been responsible for updating the TNM rules since the 7th edition, Dr. Asamura said. The staging classifications are updated as needed to take advantage of new technologies, new approaches, and new agents in cancer treatment. The association’s Staging and Prognostic Factors Committee is charged with maintaining the TNM database and updating staging criteria as appropriate.
“We are preparing some 30 articles about the results of the IASLC Staging Project for the 9th Edition TNM for lung cancer, thymic tumors, and pleural mesothelioma,” he said. “They will be published in 2023 and 2024 in the Journal of Thoracic Oncology, and I ask IASLC members and others in the field to be aware of these new publications.”
While more details will be revealed during the plenary session, Dr. Asamura shared some insights into the 9th Edition, including that the Tumor category remains unchanged. The Node category, however, is slated is to be divided into N2a, single station disease, and N2b, multi-station disease, subcategories.
Bigger changes are in store for M1, with three new subcategories. M1a is a malignant effusion with pleural dissemination and contralateral intrapulmonary metastasis. M1b is single-site metastatic disease and M1c is multi-site metastatic disease. The final TNM stage will be based on prognosis by calculating survival for each combination of T, N, and M.
Valerie Rusch, MD, FACS, Attending Thoracic Surgeon, Vice Chair of Clinical Research, and Miner Family Chair of Intrathoracic Cancers at Memorial Sloan-Kettering Cancer in New York, will discuss updates to mesothelioma staging classification. And Enrico Ruffini, MD, Professor and Chief of Thoracic Surgery, University of Torino, Torino, Italy, will introduce updates for the thymic cancer staging classifications.
“All of the changes are critically related to the stage definitions and the choice of treatment,” Dr. Asamura said. “New treatment challenges will be based on the new classifications which define the amount of tumor burden more precisely than we can currently provide.
“The publication of the 9th edition staging criteria in 2024 is not the end of our task,” he said. “We must consider the possibility of incorporating novel molecular factors into the TNM anatomic classifications. The Staging and Prognostic Factors Committee has several new projects already underway in anticipation of future TNM updates.”