Molecular cytology of the respiratory tract and pleura

Abstract

There is growing evidence that molecular testing is feasible on all types of cytological preparation, which is fortunate as more diagnostic markers and biomarkers for targeted therapies are discovered for use in pulmonary and pleural malignancies. In this article we will discuss the pre‐analytic, analytic, and post‐analytic (interpretive) considerations for successful implementation of molecular tests for diagnostic and predictive markers in respiratory and pleural cytology. The vast majority of laboratories are familiar with, and have validated their molecular protocols for, formalin‐fixed paraffin‐embedded surgical specimens, which are not directly applicable to cytology specimens. Thus, rigorous validation must be performed for each type of fixative and cytology preparation before it is implemented in the clinical setting.

Editorial

“…The current and future landscape of lung cancer tissue testing is provided by Zhou et al, and it is likely this will develop further in the next few years. 2 Suffice to say, cytopathology-type samples can be perfectly adequate for molecular/biomarker profiling, provided, of course, that there is sufficient tumour content in the sample and that the sample has been handled and processed in a way that is permissive for all the testing that may be required. This is often overlooked, but Maddox and Smart outline how to make the most of the samples obtained and discuss practical issues such as specimen types, ROSE, handling processes and the vagaries of molecular testing.…”

“…Once a non‐small cell carcinoma is subtyped, routine relevant molecular, genetic and immune checkpoint biomarkers can be appropriately pursued, and these are now essential for deciding treatment options. The current and future landscape of lung cancer tissue testing is provided by Zhou et al, and it is likely this will develop further in the next few years 2 . Suffice to say, cytopathology‐type samples can be perfectly adequate for molecular/biomarker profiling, provided, of course, that there is sufficient tumour content in the sample and that the sample has been handled and processed in a way that is permissive for all the testing that may be required.…”

Use of cytology fluid samples for predictive biomarker testing in lung cancer patients

“…Despite using cytology samples in a significant proportion of lung cancer cases, there is limited published literature 1–3 about their usage as fluid in biomarker testing, with most studies still carried out on FFPE block material.…”

Application of a Standardized Terminology and Nomenclature for Respiratory Cytology: Experience from a Large Tertiary Respiratory Cancer Centre

“…Respiratory cytology specimens include those obtained from bronchial washings, bronchial brushings, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), bronchial lavages, and, rarely, sputum [1]. These techniques are much less invasive than transthoracic lung biopsies [4], which have significant risks including pneumothorax (12-45%) and pulmonary haemorrhage [5] and therefore represent important diagnostic options for patients. The management of lung cancer involves a multidisciplinary process, and the clear communication of results is essential to this process.…”