PD-L1 Expression in Prostate Cancer: Anatomopathological Features, Methodological Pitfalls, and Therapeutic...

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Prostate cancer (PCa) is often immunologically 'cold,' with limited T-cell infiltration and immune suppression.
• Programmed death-ligand 1 (PD-L1) expression is typically low in untreated PCa but can increase in advanced or aggressive disease.
• PD-L1's role as a biomarker in PCa is unclear due to significant analytical variability in its assessment.

Purpose of the Study:

• To review the biological factors influencing PD-L1 regulation in PCa.
• To analyze methodological challenges in PD-L1 assessment (e.g., antibody clones, scoring methods, pre-analytical factors).
• To explore the correlation of PD-L1 expression with clinicopathological features and treatment responses.

Main Methods:

• Literature review synthesizing existing data on PD-L1 in prostate cancer.
• Analysis of factors contributing to heterogeneity in PD-L1 testing.
• Examination of associations between PD-L1 levels, disease characteristics, and outcomes.

Main Results:

• Higher PD-L1 expression is generally linked to adverse clinicopathological features in PCa.
• PD-L1 assessment shows considerable variability, complicating interpretation.
• PD-L1 expression may identify patients who could benefit from immune checkpoint inhibitors in specific contexts.

Conclusions:

• PD-L1 expression in PCa is influenced by disease progression and therapy.
• Standardized PD-L1 assessment methods are crucial for reliable interpretation.
• PD-L1 immunohistochemistry alone is inadequate for predicting immunotherapy efficacy in unselected PCa patients; novel biomarkers are needed.