Association Between Programmed Death-Ligand 1 Expression and the Vascular Endothelial Growth Factor Pathway in...

Area of Science:

• Oncology
• Immunology
• Vascular Biology

Background:

• Angiosarcoma is a rare vascular cancer with poor prognosis and resistance to conventional therapies.
• The tumor immune microenvironment, particularly immune checkpoint molecule expression, remains poorly understood in angiosarcoma.
• Understanding these factors is crucial for developing novel treatment strategies.

Purpose of the Study:

• To investigate the expression of programmed death-ligand 1 (PD-L1) and programmed death 1 (PD-1) in angiosarcoma.
• To correlate PD-L1 and PD-1 expression with vascular endothelial growth factor (VEGF)-related gene expression.
• To assess the association between PD-L1/PD-1 expression and clinical outcomes in angiosarcoma patients.

Main Methods:

• Retrospective analysis of 27 angiosarcoma tissue specimens (primary and metastatic).
• Immunohistochemistry (IHC) was used to characterize PD-L1 and PD-1 expression in tumor cells and tumor-infiltrating immune cells.
• RNA extraction and quantitative gene expression analysis of VEGF-related genes.

Main Results:

• PD-L1 expression was found in tumor cells (19%) and tumor-infiltrating immune cells (33%).
• PD-1 expression was identified in tumor-infiltrating immune cells (4%).
• No significant association was observed between PD-L1/PD-1 expression, VEGF-related gene expression, or patient survival.

Conclusions:

• PD-L1 and PD-1 expression is present in a notable proportion of angiosarcoma tumors and their microenvironment.
• Current findings do not support a link between PD-L1/PD-1, VEGF signaling, and prognosis in this cohort.
• Targeting the PD-1/PD-L1 pathway may still offer therapeutic potential for angiosarcoma patients refractory to standard treatments.