From Andy Nicholson and colleagues: Suitability of EBUS-TBNA Specimens for Subtyping and Genotyping of NSCLC

http://www.ncbi.nlm.nih.gov/pubmed/22505743

Am J Respir Crit Care Med. 2012 Apr 13. [Epub ahead of print]

Suitability of EBUS-TBNA Specimens for Subtyping and Genotyping of NSCLC: A Multi-Centre Study of 774 Patients.

Navani N, Brown JM, Nankivell M, Woolhouse I, Harrison RN, Jeebun V, Munavvar M, Ng BJ, Rassl DM, Falzon M, Kocjan G, Rintoul RC, Nicholson AG, Janes SM.

Source

Centre for Respiratory Research, University College London, London, United Kingdom.

Abstract

Rationale

The current management of advanced non-small cell lung cancer (NSCLC) requires differentiation between squamous and non-squamous sub-types 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 whether cytology specimens obtained with EBUS-TBNA are suitable for the sub-classification 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 5 centres 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% CI 73% - 80%). The rate of NSCLC not otherwise specified (NSCLC-NOS) was significantly reduced in patients who underwent immunohistochemistry (adjusted OR 0.50 95% CI 0.28 - 0.82, P=0.016). EGFR mutation analysis was possible in 107 (90%) of the 119 patients in whom mutation analysis was requested. The sensitivity, negative predictive value and diagnostic accuracy of EBUS-TBNA in patients with NSCLC was 88% (95% CI 86% - 91%), 72% (95% CI 66% - 77%) and 91% (95% CI 89% - 93%) respectively. 

Conclusions

This large multi-centre pragmatic study demonstrates that cytology samples obtained from EBUS-TBNA in routine practice are suitable for sub-typing of NSCLC and EGFR mutation analysis and that use of immunohistochemistry reduces the rate of NSCLC-NOS.