From Tumour to Bloodstream: Advancing PD-L1 Testing With Liquid Biopsies in Non-Small Cell Lung Cancer.

Area of Science:

• Oncology
• Immunology
• Molecular Diagnostics

Background:

• Immune checkpoint inhibitors (ICIs) have transformed non-small cell lung cancer (NSCLC) treatment, particularly for tumors lacking actionable genomic alterations.
• Current reliance on immunohistochemistry (IHC) for Programmed Death-Ligand 1 (PD-L1) assessment has modest predictive value, limiting optimal ICI benefit for many patients.

Purpose of the Study:

• To explore the potential of liquid biopsy as a complementary tool to tissue-based PD-L1 assessment in NSCLC.
• To review the predictive and prognostic value of liquid biopsy in advanced NSCLC for patient selection and treatment individualization.
• To discuss the technical and clinical implications of liquid biopsy in precision immuno-oncology.

Main Methods:

• A narrative review of recent advancements and ongoing research in liquid biopsy for NSCLC.
• Analysis of biomarkers such as circulating tumor cells (CTCs), extracellular vesicles (EVs), and circulating tumor DNA (ctDNA).
• Evaluation of liquid biopsy's role in tracking disease evolution and immune system interactions.

Main Results:

• Liquid biopsy offers a non-invasive method for assessing biomarkers like PD-L1, potentially enhancing patient selection for ICIs.
• Emerging evidence suggests liquid biopsy can provide predictive and prognostic information in advanced NSCLC.
• Advancements in liquid biopsy techniques are crucial for driving precision immuno-oncology.

Conclusions:

• Liquid biopsy holds significant potential to overcome the limitations of tissue-based PD-L1 assays in NSCLC.
• Establishing standardized and reproducible liquid biopsy methods is essential for clinical implementation.
• This approach promises to enable more individualized immunotherapy strategies for NSCLC patients.