Editor’s Note: For more on staging and prognostic factors, read a new commentary on the challenges—and possible alternative approaches—to improving nodal staging.
For the past 20 years, the IASLC Staging Project has provided evidence-based recommendations for the TNM Classification for Thoracic Cancers, which is published by the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC). The Staging Project—spearheaded by the association’s Staging and Prognostic Factors Committee (SPFC)—is now working on a third round of recommendations ahead of the publication of the 9th edition of the TNM Classification.
Led by SPFC Chair Hisao Asamura, MD, the IASLC Staging Project is an international effort to study and improve the staging system for lung cancer, as well as for thymic and esophageal cancers and mesothelioma. Recommendations for the 9th edition will—for the first time—consider new data elements, including genetic biomarkers, protein alterations, and copy number alterations. Dr. Asamura, of Keio University School of Medicine, Japan, recently provided an update on the project during an interview with ILCN.
ILCN: The SPFC’s recent update on the IASLC’s staging project includes a look at a new database of lung cancer cases. Tell us a little about this database and how the committee will use that data to inform proposed revisions for the 9th edition of TNM classification system.
Dr. Asamura: The SPFC is finalizing its recommendations for the 9th edition of TNM classification for lung cancer, thymic tumors, and mesothelioma, which will be then sent to the UICC and AJCC for consideration. Revised recommendations are based on the analyses and simulation of the updated data from the Staging Project database.
The newly established database is composed of 124,581 cases. The data were obtained from Asia and Australia (56.0%), Europe (24.7%), North America (15.7%), South/Central America (3.4%), and Africa and the Middle East (0.1%). After cases with incomplete data are excluded, 87,043 cases are to be included in the analysis. Analyses of this database are expected to provide proposals for changing the TNM classification for the 9th edition. This newly established global database on lung cancer will provide fundamental elements for revisions of the TNM rules for staging lung cancer.
ILCN: Staging is a hotly debated topic in the lung cancer community. How does the staging committee handle the challenge of trying to develop an accurate, evidence-based TNM classification system while preventing it from becoming overly complicated?
Dr. Asamura: A scientifically accurate and easily accessible staging system is what every clinician or researcher seeks. As SPFC members, we well understand this concept and make every possible effort to realize this ideal staging system. Needless to say, the TNM staging system is based upon the accurate description of the anatomic extent of cancer exclusively. For a more sophisticated staging system, we are trying to include non-anatomic factors such as molecular and biological parameters. The lung cancer community will see the outcomes of our efforts soon.
ILCN: What is the timeline for the 9th edition of the TNM classification system?
Dr. Asamura: The important date for 9th edition of the TNM is January 1, 2024. That is when we will start using the new 9th edition. Aiming at this date, the SPFC is now finalizing the revision of the classification, and we will be launching the core papers in 2023, including the database overview and the tumor, node, metastases, and stage grouping. Thymic papers will also be published in 2023. The publication of a staging manual and staging handbook are also scheduled.
ILCN: Looking to the future, as the field of lung cancer evolves, some have wondered if molecular staging may become preferable to nodal staging. Do you see molecular staging as a possibility down the road? Either alone or as a companion to nodal staging? What are the challenges to developing and implementing a molecular staging system?
Dr. Asamura: Yes, SPFC has 14 subcommittees for lung cancer, including a novel and active molecular subcommittee chaired by Drs. Fred Hirsch and David Carbone. By combining nonanatomic factors with anatomic factors, we will be able to more accurately anticipate the prognosis of the individual patient and understand the response to the treatment. We are on our way.
ILCN: Is there anything else readers should know about the staging project or the Staging and Prognostic Factors Committee?
Dr. Asamura: The staging project is based on the voluntarily submitted data of the patients from around the world. The cooperation of IASLC members on this project is indispensable and very much appreciated. This new database exists because of these sincere efforts.