Suitability of endobronchial ultrasound-guided transbronchial needle aspiration specimens for subtyping and genotyping of non-small cell lung cancer: a multicenter study of 774 patients.

Rationale: The current management of advanced non–small cell lung cancer (NSCLC) requires differentiation between squamous and nonsquamous subtypes as well as epidermal growth factor receptor (EGFR) mutation status. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is increasingly used for the diagnosis and staging of lung cancer. However, it is unclear whethercytologyspecimensobtainedwithEBUS-TBNAaresuitable for the subclassification and genotyping of NSCLC. Objectives: To determine whether cytology specimens obtained from EBUS-TBNA in routine practice are suitable for phenotyping and genotyping of NSCLC. Methods: Cytological diagnoses from EBUS-TBNA were recorded from 774 patients with known or suspected lung cancer across five centers in the United Kingdom between 2009 and 2011. Measurements and Main Results: The proportion of patients with a final diagnosis by EBUS-TBNA in whom subtype was classified was 77% (95% confidence interval [CI], 73–80). The rate of NSCLC not otherwisespecified(NSCLC-NOS)wassignificantlyreducedinpatientswho underwent immunohistochemistry (adjusted odds ratio, 0.50; 95% CI, 0.28–0.82;P¼0.016).EGFRmutationanalysiswaspossiblein107(90%) of the 119 patients in whom mutation analysis was requested. The sensitivity, negative predictive value, and diagnostic accuracy of EBUSTBNA in patients with NSCLC were 88% (95% CI, 86–91), 72% (95% CI, 66–77), and 91% (95% CI, 89–93), respectively. Conclusions: This large, multicenter, pragmatic study demonstrates