Objective:

To discuss the role of extracellular vesicles (EVs) in immune checkpoint regulation in breast cancer and their contribution to immune evasion and therapy resistance.

Approach:

• Literature Review: A review of studies from the past decade related to EV biology, immune checkpoints, and breast cancer was conducted using PubMed, Google Scholar, and Web of Science.

Key Findings:

• Tumor-derived EVs contribute to immunosuppression by impairing T-cell function and promoting immune tolerance.
• EVs facilitate metastatic progression and support resistance to immunotherapy.
• EV-mediated effects vary across different breast cancer subtypes, influencing treatment response and clinical outcomes.
• EVs may serve as minimally invasive biomarkers for disease monitoring and as therapeutic targets or delivery systems for precision medicine.

Interpretation:

EVs are implicated in modulating immune responses in breast cancer, particularly through the regulation of immune checkpoints such as PD-L1 and CTLA-4.

Limitations:

• The integration of EVs' mechanistic involvement in immune checkpoint regulation with clinical applications remains insufficiently explored.
• Further research is needed to evaluate the potential of EVs as diagnostic biomarkers and therapeutic targets.

Conclusion:

This review discusses the role of EV-mediated immune checkpoint regulation in breast cancer, highlighting the complexity of these interactions and the potential of PD-L1 and CTLA-4 as targets for immunotherapy.