IASLC Staging Articles
- Thymic epithelial tumors are presently staged using a consistent TNM classification developed by the International Association for the Study of Lung Cancer (IASLC) and approved by the Union for International Cancer Control and the American Joint Committee on Cancer. The stage classification is incorporated in the eight edition of the TNM classification of thoracic malignancies. The IASLC Staging and Prognostic Factors Committee (SPFC)—Thymic Domain (TD) is in charge for the next (ninth) edition expected in 2024.
- Stage classification provides a consistent and concise nomenclature about the anatomic extent of the cancer. This is a fundamental cornerstone in the management of patients; it enables reporting results and facilitates comparing one treatment to another and judging how closely clinical trial results apply to an individual patient. A nomenclature must be relatively static; however, periodical refinement is needed to adjust to a changing landscape of clinical relevance. Changes must be well justified and thoughtfully developed to maintain the ability to communicate clearly and facilitate comparisons across time.
- One of the most significant modifications that emerged from the eighth edition of TNM in the staging of pulmonary adenocarcinoma (ADC) was the introduction of the concept that only invasive size should be used for the size T-descriptor in part-lepidic nonmucinous ADCs. According to the 2011 International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society, and 2015 WHO lung adenocarcinoma classifications, the lepidic pattern is now regarded as a noninvasive growth pattern.
- The American Joint Committee on Cancer (AJCC) eighth edition TNM staging manual for NSCLC, derived from the International Association for the Study of Lung Cancer (IASLC) Staging Project, designates tumors with additional nodule(s) in the same lobe as T3. This study sought to externally validate the results of the IASLC, which showed a trend in improved survival for such tumors, but excluded treatment-based adjustment, by assessing whether these tumors have worse survival than T2b NSCLC.