Defining N2 Disease in Non-Small Cell Lung Cancer

Simply defined, N2 disease in non-small cell lung cancer (NSCLC) is the presence of ipsilateral mediastinal nodal metastases. This definition does little justice to what is in actuality a heterogeneous and challenging patient population. The presence of ipsilateral mediastinal nodal metastases (N2 disease) in NSCLC is a poor prognostic sign. This article demonstrates that the definition of N2 disease includes many subgroupings with widely disparate effects on prognosis.