Any operation for lung cancer that is planned as curative includes dissection of the lymph nodes in the mediastinum in order to allow correct staging of the disease. It is well known that ipsilateral lymph node metastases (N2) mean a poor prognosis. Since most patients with this finding die from metastatic tumor progression within 3 years after the operation, it can be assumed that positive findings in the mediastinal lymph nodes represent generalization of the cancer. Therefore, the probability of a therapeutic effect from more radical removal of lymph nodes in the mediastinum is rather low. On the other hand, it is justified to apply and evaluate additional systemic treatment in these tumor stages.