In the era of ultrasound technology, could conventional trans-bronchial needle aspiration still play a role in lung cancer mediastinal staging?

Background: To evaluate the feasibility of a combined strategy including conventional-trans-bronchial needle aspiration biopsy (C-TBNA) and endobronchial ultrasounds transbronchial needle aspiration (EBUS-TBNA) for sampling mediastinal adenopathies in patients with lung cancer in order to determinate whether in the era of ultrasound technology C-TBNA could still play a role in mediastinal staging.

Methods: It was a retrospective multicenter study including all consecutive patients with lung cancer and radiological mediastinal adenopathies undergoing TBNA for mediastinal staging (January 2014 - July 2016). C-TBNA was performed as first diagnostic procedure. All negative C-TBNA results were corroborated by EBUS-TBNA, and, if EBUS-TBNA was negative, by mediastinoscopy or surgery. The diagnostic yield of C-TBNA were then calculated.

Results: A total of 175 patients were included in the study for a total of 197 mediastinal adenopathies sampled. C-TBNA was positive in 125 cases and negative in 72 cases who underwent EBUS-TBNA. It was positive in 58 cases and negative in 14 patients. After surgical exploration (n=12) and mediastinoscopy (n=2), 11 patients did not present metastases (true negative) while 3 presented mediastinal involvement (false negative). Thus, C-TBNA had a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 67.2%, 100%, 100%, 15.3% and 69.0%, respectively. The sensitivity increased for sampling paratracheal versus subcarinal stations (80% versus 49%; P<0.001); and large adenopathies (≥15 mm) versus small adenopathies (<15 mm) (83% versus 43%; P<0.001). In all re-staging patients (n=4), Conventional-TBNA results were false negative.

Conclusions: The combined use of C-TBNA and EBUS-TBNA as the most cost-effective strategy in the setting of mediastinal staging. C-TBNA performed before EBUS-TBNA is indicated for sampling large mediastinal adenopathies near to carina while EBUS-TBNA remains the first choice for puncturing small adenopathies far from carina and for re-staging after induction therapy.