Lung Molecular Cytopathology: EGFR and Beyond

Area of Science:

• Oncology
• Molecular Biology
• Pathology

Background:

• Lung cancer (LC) is the primary cause of cancer-related mortality globally.
• Most LC patients present with advanced disease, limiting treatment options and resulting in poor prognoses.
• Small biopsy or cytology specimens are crucial for diagnosing advanced LC when surgical resection is not feasible.

Purpose of the Study:

• To review biomarker testing strategies using cytology specimens for non-small cell lung cancer (NSCLC).
• To highlight the importance of accurate biomarker testing for personalized treatment selection in advanced NSCLC.
• To discuss the role of molecular drivers and predictive biomarkers in guiding NSCLC therapy.

Main Methods:

• Review of current literature on biomarker testing in cytology specimens for NSCLC.
• Discussion of molecular alterations (e.g., EGFR, ALK, ROS1) and their targeted therapies.
• Examination of programmed death ligand-1 (PD-L1) testing for immunotherapy selection.

Main Results:

• Biomarker testing in cytology specimens is essential for identifying actionable molecular alterations in NSCLC.
• Targeted therapies for EGFR mutations, ALK fusions, and ROS1 rearrangements have revolutionized NSCLC treatment.
• PD-L1 expression analysis in cytology samples aids in predicting response to immunotherapy.

Conclusions:

• Cytology specimens are a viable source for comprehensive biomarker testing in advanced NSCLC.
• Accurate and timely biomarker testing from cytology samples is critical for implementing personalized treatment strategies.
• Advances in molecular diagnostics and immunotherapy have significantly improved outcomes for NSCLC patients.