Presurgical invasive mediastinal staging in lung cancer, unexpected N2 and long-term survival: a registry-based study with data from the Spanish group for video-assisted thoracic surgery.

Background: Mediastinal lymph node staging is a key element in the diagnosis of lung cancer. The combination of computed tomography (CT) and positron emission tomography (PET) has improved staging but some circumstances are known to influence their negative predictive value. The objective of this study was to assess the impact on survival of avoiding invasive mediastinal staging in surgical lung cancer patients with negative mediastinum in CT and PET and intermediate risk of unexpected pN2.