Arvind K Chaturvedi
Staging cancers is an essential component of oncology practice. TNM staging system provides a common language to communicate on the disease extent of an individual patient. It groups patients with similar levels of disease and similar outcomes together. It is crucial in decision making on management of cancers and predicting prognosis. With advances in treatment and development of new drugs and strategies, the outcomes and survival statistics change over time. As such, there is a need for reviewing the staging system every few years. TNM 8th edition is currently in practice and it has some big changes in staging of lung cancer. The importance of tumor size is highlighted in the new staging system and the T stage descriptor changes with every cm increase in tumor size. Nodal stage has largely remained unchanged but N descriptors have been proposed for future validation. There is no change in M1a, as a departure from the past oligometastases has been recognized as a separate category. Single metastasis in a single organ is M1b while multiple metastases in a single or multiple organ is now M1c. The purpose of this lecture is to look at the rationale behind the changes in staging of lung cancers, getting familiar with the new staging system and the optimal evaluating tools to accurately stage lung cancers.