Endobronchial ultrasound in real life: primary diagnosis and mediastinal staging of lung cancer in patients submitted to thoracic surgery

Background: Since the first articles published for over 10 years ago, endobronchial ultrasound (EBUS) has gained a strong scientific backing and has been incorporated into routine medical practice in pulmonology and thoracic surgery centers. How is EBUS performing outside the scientific environment, as a diagnostic and mediastinal staging tool in a subset of patients that undergo thoracic surgery, is an interesting question. Methods: This study evaluated consecutive patients who, during the period from January 2010 to August 2012, were submitted to EBUS and later to thoracic surgery. The samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) were compared to surgical samples. The primary endpoint was the proportion of patients with a final diagnosis of non-small cell lung cancer (NSCLC) by EBUS-TBNA correctly subtyped. The secondary endpoint was the negative predictive value (NPV) of EBUS-TBNA for mediastinal staging of lung cancer. Results: Two hundred eighty seven patients were studied. Considering 84 patients with a final diagnosis of NSCLC by EBUS-TBNA, 79 % (CI 95 % 70.1-87.3) were correctly subclassified. The NPV of EBUS-TBNA for mediastinal staging was 89 % (IC 95 % 84.9-92.7). From a total of 21 false negative cases of mediastinal staging, 16 (76 %) did not undergo positron emission tomography-computed tomography (PET-CT) before the EBUS and in 15 (71 %) the affected lymph node chain was not punctured by EBUS-TBNA. Ten (47 %) patients had only lymph node metastases not directly accessible by the EBUS. Conclusions: Performed in hospital routine and in patients submitted to thoracic surgery, EBUS-TBNA proved to be a good tool for proper pathological diagnosis of lung cancer. The negative predictive value of 89 % for mediastinal staging of lung cancer is comparable to that reported in previous studies, but the relatively high number of 21 false negative cases points to the need for standardization of routine strategies before, during and after EBUS.