Endoscopic mediastinal staging of lung cancer

The advent of endoscopic ultrasound-guided sampling procedures such as endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has lead to significant advances in the mediastinal diagnosis and staging of lung cancer. These endoscopic techniques can be performed in the outpatient setting under conscious sedation and local anesthesia, in contrast to the surgical standard, mediastinoscopy (MS), which requires operating theatre time and general anesthesia. Proponents of mediastinoscopy have always emphasized the advantages of mediastinoscopy, namely its sensitivity even with a low prevalence of mediastinal metastases and its low false negative rate. Newer endoscopic techniques such as EBUS-TBNA are showing sensitivities exceeding that of mediastinoscopy, even in the setting of an equally low prevalence of mediastinal metastases. However, endoscopic techniques have double the false negative rate of mediastinoscopy. As the tracheobronchial route and esophageal route provide almost complete access to mediastinal lymph nodes, these endoscopic techniques are complementary rather than competing. When used in combination, it is possible mediastinoscopy may be superseded. The challenge however, is how best to select the appropriate endoscopic procedures to accurately stage lung cancer in the most cost-effective manner.