Endoscopic ultrasound and staging of non-small cell lung cancer.

Accurate cancer staging allows the most favorable therapy and prognosis of a neoplastic process, and allows consistency when performing clinical trials for different stages of tumors. In the case of non small-cell lung cancer (NSCLC), the most important parameters for optimal treatment and prognosis are the presence of cancer spread to the lymph nodes within the mediastinum, and to distant organs. Endoscopic ultrasound (EUS) has become a significant tool for the assessment of mediastinal lymph nodes, and in some cases, distant organ metastases because of its minimally invasive access to these sites through a trans-esophageal or trans-gastric approach. The capability of performing fine needle aspiration (FNA) has greatly improved the accuracy and popularity of EUS for lung cancer staging. This review will outline the basic principals of lung cancer staging, EUS-FNA techniques, and role of EUS-FNA in lung cancer staging.