Endobronchial ultrasound-guided transbronchial needle biopsy for M1 staging of extrathoracic malignancies

Background: Extrathoracic malignancies metastasize to the mediastinum and/or pulmonary hilum. Mediastinoscopy and thoracoscopy are standard to obtain tissue proof of metastatic spread but are invasive. Endobronchial ultrasound with real-time-guided transbronchial fine-needle aspiration (EBUS-TBNA) is a minimally invasive alternative for surgical staging of lung cancer. Methods: We analysed the test characteristics of EBUS-TBNA in consecutive patients with a suspicion of mediastinal or hilar metastases of various extrathoracic malignancies. Results: Ninety-two patients with concurrent (n = 33) or previously diagnosed and treated (n = 59) extrathoracic malignancies were evaluated. EBUS-TBNA detected mediastinal or hilar metastatic spread in 52 patients (57%) [metastasis of extrathoracic tumour in 40 (44%) and second malignancies (lung cancer) in 12 (13%)]. Subsequent surgical staging showed malignancy in another nine patients. With EBUS-TBNA, an alternate diagnosis was found in four. Sensitivity and negative predictive value for mediastinal or hilar metastatic spread were 85% [95% confidence interval (CI) 73-93] and 76% (95% CI 59-88). EBUS-TBNA prevented an invasive surgical procedure in 61% of the patients. One patient had a respiratory arrest during EBUS-TBNA; abortion lead to full recovery without further intervention. Conclusions: EBUS-TBNA is a minimally invasive method for M staging of patients with extrathoracic malignancies to confirm mediastinal or hilar spread. EBUS-TBNA therefore may qualify as an alternative for surgical staging.