Mediastinoscopy in patients with lung cancer and negative endobronchial ultrasound guided needle aspiration

Background: Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has been proposed as a safe, less-invasive alternative to mediastinoscopy to stage mediastinal lymph nodes in patients with lung cancer. We evaluated the negative predictive value of EBUS-TBNA in lung cancer patients suspected of having N2 nodal metastases. Methods: This study is a single-institution retrospective review of cases with suspected or confirmed lung cancer undergoing mediastinoscopy after a negative EBUS-TBNA between June 2006 and February 2008. Results: A total of 494 patients underwent EBUS-TBNA during the study period. Twenty-nine patients with suspected or confirmed lung cancer had a negative EBUS-TBNA and underwent subsequent mediastinoscopy. Mediastinoscopy was performed for findings suspicious of N2 disease based on noninvasive imaging. Mediastinoscopy found metastatic nodes in eight of 29 patients (28%) for a patient-specific negative predictive value of EBUS-TBNA of 72% (95% CI, 56% to 89%). Mediastinal lymph node dissection found four further patients with positive N2 nodes (19%). The EBUS-TBNA and mediastinoscopy sampled the same lymph node station on 36 occasions in the 29 patients. The average lymph node size was 10 mm. Mediastinoscopy was positive in 5 of 36 stations, for a nodal-specific negative predictive value of EBUS-TBNA of 86% (95% CI, 75% to 97%). Conclusions: Endobronchial ultrasound with transbronchial needle aspiration can effectively sample mediastinal lymph node stations in patients with lung cancer. However, in this early experience, 28% of patients with high clinical suspicion of nodal disease had N2 mediastinal nodal metastases confirmed by mediastinoscopy despite negative EBUS-TBNA.