Biomarker Testing in Lung Carcinoma Cytology Specimens: A Perspective From Members of the Pulmonary Pathology Society

TLDR

Targeted therapy has shifted lung cancer care, making accurate cytologic subtyping and molecular testing essential, yet cytologic specimens—though advantageous—are underused, and most lung cancers are diagnosed by aspiration or exfoliation, necessitating optimized triage for diagnosis and biomarker studies. The review evaluates the utility and adequacy of cytologic specimens for lung cancer diagnosis and ancillary studies, focusing on the opportunities and challenges of using them for molecular diagnosis in the molecular era. The review examines how to triage and best use aspiration or exfoliative cytology specimens for diagnosis and biomarker studies, addressing opportunities and challenges in molecular diagnosis of lung cancer.

Abstract

The advent of targeted therapy in lung cancer has heralded a paradigm shift in the practice of cytopathology with the need for accurately subtyping lung carcinoma, as well as providing adequate material for molecular studies, to help guide clinical and therapeutic decisions. The variety and versatility of cytologic-specimen preparations offer significant advantages to molecular testing; however, they frequently remain underused. Therefore, evaluating the utility and adequacy of cytologic specimens is critical, not only from a lung cancer diagnosis standpoint but also for the myriad ancillary studies that are necessary to provide appropriate clinical management. A large fraction of lung cancers are diagnosed by aspiration or exfoliative cytology specimens, and thus, optimizing strategies to triage and best use the tissue for diagnosis and biomarker studies forms a critical component of lung cancer management. This review focuses on the opportunities and challenges of using cytologic specimens for molecular diagnosis of lung cancer and the role of cytopathology in the molecular era.