The International Association for the Study of Lung Cancer Mesothelioma Staging Project: Proposals for the "N" Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Pleural Mesothelioma

Andrea Bille; R Taylor Ripley; Dorothy J Giroux; Ritu R Gill; Hedy L Kindler; Anna K Nowak; Isabelle Opitz; Harvey I Pass; Andrea Wolf; David Rice; Valerie W Rusch; Members of the Staging and Prognostic Factors Committee, Advisory Boards, and Participating Institutions

doi:10.1016/j.jtho.2024.05.003

The International Association for the Study of Lung Cancer Mesothelioma Staging Project: Proposals for the "N" Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Pleural Mesothelioma

J Thorac Oncol. 2024 May 9:S1556-0864(24)00208-9. doi: 10.1016/j.jtho.2024.05.003. Online ahead of print.

Affiliations

¹ Thoracic Surgery Department, Guy's Hospital, London, United Kingdom. Electronic address: andrea.bille@gstt.nhs.uk.
² Department of Thoracic Surgery, Baylor College of Medicine, Houston, Texas.
³ Cancer Research And Biostatistics, Seattle, Washington.
⁴ Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
⁵ Department of Medicine, Section of Hematology/Oncology, University of Chicago, Chicago, Illinois.
⁶ National Centre for Asbestos-Related Diseases, Medical School, University of Western Australia, Crawley, Western Australia, Australia.
⁷ Department of Thoracic Surgery, University Hospital, Zurich, Switzerland.
⁸ Department of Thoracic Surgery, NYU Langone Medical Center, New York, New York.
⁹ Department of Cardiothoracic Surgery, Icahn School of Medicine at Mt. Sinai, New York, New York.
¹⁰ Department of Thoracic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
¹¹ Thoracic Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York.

PMID: 38734073
DOI: 10.1016/j.jtho.2024.05.003

Abstract

Introduction: The International Association for the Study of Lung Cancer developed an international database to inform potential revisions in the ninth edition of the TNM classification of diffuse pleural mesothelioma (PM). This study analyzed the clinical and pathologic N categories to determine whether revisions were indicated relative to the eighth edition staging system.

Methods: Of 7338 PM cases diagnosed from 2013 to 2022 and 3598 met all inclusion criteria for planned analyses. Data on 2836 patients without metastases were included in this study. Overall survival (OS) was measured from date of diagnosis. Patients were included regardless of whether they received neoadjuvant treatment. For the pathologic N analysis, patients who underwent resection (extrapleural pneumonectomy or pleurectomy/decortication) were included. N subgroups were analyzed and OS assessed by the Kaplan-Meier method.

Results: The existing eighth edition N categories were performed adequately in the ninth edition data set. A median OS advantage was noted for clinical and pathologic N0 versus N1 patients: 23.2 versus 18.5 and 33.8 versus 25.0 months, respectively. Patients with resected pN0 had a 3-year OS of 48%. No difference in OS was noted for single- versus multiple-station nodal metastases. The number of nodal stations sampled at the time of resection was not associated with a difference in OS.

Conclusions: Data regarding clinical and pathologic N categories corroborate those used in the eighth edition. No changes in the N categories are recommended in the ninth edition of PM staging system.

Keywords: Malignant pleural mesothelioma; Nodal metastases; Staging; TNM classification.