The new lung cancer TNM classification: Review and clinical implications

Lung cancer remains the number one cause of cancer-related mortality in the Western world. Its staging is the cornerstone for both prognosis and treatment guidance. A unified and universally accepted staging system is also essential to standardize nomenclature for international comparisons of clinical trials. The UICC 7th edition of the TNM classification system is undoubtedly a major improvement in our scientific basis for the staging of lung cancer, supported by a large international database and subject to thorough internal and external validation process. Some limitations are deeply related to the retrospective nature of the data collection and will hopefully be overcome with the new prospective data set developed by the IASLC to inform changes to the eighth TNM. In this chapter, we will review the modifications to the T, N, and M descriptors, as well as the group stages, and we will discuss its clinical implications, strengths, and limitations.