Results of N1 and N2 surgery in non-small cell lung cancer

Lymph node involvement in non-small cell lung cancer shows considerable heterogeneity within the N1 and N2 descriptors with respect to localization, the number of lymph nodes affected and the extent of mass and volume. In an attempt to reflect the different prognostic behavior of lymph node metastases, the 8th classification of the TNM has been published with proposals for further subtyping of the N1 and N2 stages into N1a, N1b, as well as N2a1, N2a2, and N2b. The aim of this article is to discuss the value of surgery of non-small cell lung cancer in the N1 and N2 lymph node metastatic stages. While overall survival benefits were seen after concomitant chemotherapy for patients with N1 metastatic disease and surgery, radiotherapy concepts did not provide any survival benefit in this subgroup. For patients with N2 metastasis, surgical resection is part of a multimodal treatment concept with chemotherapy and radiotherapy. Careful restaging after neoadjuvant therapy is recommended in order to provide surgical treatment to patients deemed suitable for curative (R0) resection. In particular, it should be noted that after inductive chemoradiotherapy, patients should only be treated by pneumonectomy in specialized centers, as resection can be associated with a high risk of postoperative complications. With respect to the new subtyping of the N2 involvement situation in N2a1, N2a2, and N2b, further adapted multimodal treatment concepts are expected in the future. Initial results are reported for stage IIIA patients and the use of video-assisted thoracoscopic surgery (VATS), robotic assisted thoracic surgery (RAST) and thoracotomy for local resection. These indicate that the use of minimally invasive techniques can achieve comparable results to open thoracotomy procedures, at least in specialized treatment centers.