Molecular analysis of endobronchial ultrasound needle aspirates in patients with non-small cell lung cancer: Results from the SCOPE database

Objective

Molecular subtyping of non-small cell lung cancer (NSCLC) is critical in the diagnostic evaluation of patients with advanced disease. This study aimed to examine whether samples from endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of intrathoracic lymph nodes and/or lung lesions are adequate for molecular analysis across various institutions.

Methods

We retrospectively reviewed all cases of linear EBUS-TBNA with a final bronchoscopic diagnosis of NSCLC entered in the Stather Canadian Outcomes registry for chest ProcEdures database. The primary outcome was specimen inadequacy rate for each molecular target, as defined by the local laboratory or pathologist.

Results

A total of 866 EBUS-TBNA procedures for NSCLC were identified. Specimen inadequacy rates were 3.8% for EGFR, 2.5% for ALK-1 and 3.5% for PD-L1. Largest target size was not different between adequate and inadequate specimens, and rapid onsite evaluation did not increase specimen adequacy rates. One centre using next-generation sequencing for EGFR had lower adequacy rates than 2 others using matrix-assisted laser desorption/ionization time-of-flight mass spectrophotometry.

Conclusion

EBUS-TBNA specimens have a very low-specimen inadequacy rate for molecular subtyping of non-small cell lung cancer.