The Prognostic Impact of Main Bronchial Lymph Node Involvement in Non-Small Cell Lung Carcinoma: Suggestions for a Modification of the Staging System

Background. The therapeutic strategies for non-small cell lung carcinoma (NSCLC) with N1 and N2 disease differ remarkably. Debate exists about the definition of the borderline between N1 and N2 stations. This study evaluated the prognostic effect of N1 disease, especially focused on the significance of the main bronchial node (No. 10) vs N2 disease. Methods. The records of 1601 patients who underwent complete pulmonary resection for NSCLC were reviewed to examine the clinical features of lymph nodal involvement. Results. There were 1086 patients (67.8%) with pN0 disease, 202 (12.6%) with pN1, and 274 (17.1%) with pN2 disease; overall 5-year survival rates were 74.7%, 56.1% and 28.9%, respectively (p < 0.001). Overall 5-year survival rates were 60.2% in hilar N1 and 49.6% in intralobar N1. Overall 5-year survival rates were 58.6% in N1 without node 10 and 35.1% in N1 with node 10. A significant difference was observed between N0 and N1 without node 10 (p < 0.001), and N1 without node 10 and N1 with node 10 (p = 0.033); however, the difference between N1 with node 10 and N2 was not significant. The status of node 10 involvement was an independent prognostic factor of pN1 patients, as well as age and gender. Conclusions. Patients with node 10-positive N1 disease have an unfavorable prognosis, and the disease behaves like N2 disease. The definition of clear borderline between N1 and N2 is mandatory to achieve a uniform classification map. This study offers further information for clinical and therapeutic purposes. (Ann Thorac Surg 2009;88:1583-8) (C) 2009 by The Society of Thoracic Surgeons