Challenges and Opportunities for Identifying Non–Small Cell Lung Cancer Biomarkers Using Bronchoscopy

Abstract

Non–small cell lung cancer is no longer viewed as a single disease, but a constellation of cancer types that benefit from different treatments. Advancements in the identification of driver mutations with specific Food and Drug Administration–regulated molecular tests have been approved for matching the right treatment to the right patient. These biomarkers, referred to as theranostic biomarkers, because of their ability to support treatment decisions and predict a clinical response are changing the way oncologists formulate non–small cell lung cancer treatment plans. Currently approved biomarker tests for lung cancer include fluorescence in situ hybridization testing for genetic rearrangements and reverse-transcriptase polymerase chain reaction testing for genetic mutations. As the use of molecular medicine progresses, an emerging treatment challenge in thoracic oncology is using limited cytologic material to reliably measure the essential theranostic biomarkers. The majority of newly diagnosed lung cancer patients have advanced disease at the time of presentation, and often undergo the least invasive biopsy possible to ascertain a diagnosis and disease stage. As less invasive diagnostic techniques become more common, it is critical to optimize collection and minimize loss of cancer tissue during processing. The physicians performing these procedures must be knowledgeable about tissue requirements for molecular testing based on tumor type, and should develop collection strategies to optimize molecular biomarker testing. This review explores current literature recommendations to maximize the collection and processing of cytology material for biomarker evaluation and evaluate which cytology samples provide the best yields. As our ability to truly individualize lung cancer therapy evolves, it will be critical to reliably evaluate and treat based on biomarker analysis.