Acquired resistance to tyrosine kinase inhibitors in non-small cell lung cancers: The role of next-generation sequencing on endobronchial ultrasound-guided transbronchial needle aspiration samples

Context.— Molecular testing is essential for the diagnostic workup of patients with advanced non–small cell lung cancers. Cytology specimens from minimally invasive procedures, such as endobronchial ultrasound–guided transbronchial needle aspiration, are often the only available samples for these patients. The implementation of molecular diagnostic testing, and in particular next-generation sequencing–based testing, on these cytologic specimens is currently an evolving field for lung cytopathology. The application of these molecular analyses on tyrosine kinase inhibitor–resistant non–small cell lung cancers raises unique technical, biologic, and clinical challenges. Objective.— To provide an overview of the implementation of next-generation sequencing analysis on endobronchial ultrasound–guided transbronchial needle aspiration samples to detect the molecular aberrations underneath the phenomenon of acquired resistance in patients with non–small cell lung cancers progressing while on the EGFR/ALK tyrosine ...