The importance of accurate lymph node staging in early and locally advanced non-small cell lung cancer: An update on available techniques

Medical oncologists are faced with multiple factors to consider when staging a patient with suspected or confirmed non-small cell lung cancer (NSCLC). Identifying pathological nodal (N2) disease is, however, of great importance because its presence significantly affects outcomes and potential treatment strategies. Recent data supporting the use of adjuvant or neoadjuvant therapies in these patients suggests that every reasonable effort should be made to assess the lymph node status accurately in patients with clinical early stage disease as well as in those with clinically staged N2 disease who have undergone preoperative treatments. Newer procedures such as integrated positron emission tomography computed tomography and esophageal or endobronchial endoscopic ultrasound with fine needle aspiration are mininially invasive techniques that may enhance the accuracy of mediastinal staging, traditionally devoted to mediastinoscopy. As their availability widens, they are likely to become an important part of staging and treatment paradigms. Intraoperatively, a growing body of evidence Suggests that lymph node dissection can be performed safely, and should replace sampling as a more effective means of identifying unsuspected N2 disease. This paper will review the current literature on staging NSCLC with regard to the detection of I nodal disease through preoperative staging of the mediastinum, the use of intraoperative lymph node sampling or dissection at the time of resection, and procedures for use in restaging patients with clinical stage IIIA N2 disease who have undergone preoperative chemotherapy (with or without radiotherapy).