The new staging system for lung cancer: imaging and clinical implications.

Accurate staging of lung cancer is necessary to describe and communicate disease extent, predict prognosis, determine therapy, and evaluate the results of clinical trials. The Union Internationale Contre le Cancer and the American Joint Committee on Cancer published the seventh edition of tumor, node, and metastasis in lung cancer in 2009. Changes to the sixth edition have been based on the analysis of a large database of patients with lung cancer by the International Staging Committee of the International Association for the Study of Lung Cancer. This study reviews the new seventh edition of the tumor, node, and metastasis lung cancer staging system and discusses the radiologic and therapeutic implications.