Platelets as regulators of cancer immunity: mechanisms and therapeutic perspectives

Platelets correspond to one of the most abundant components of the blood and shape the tumor microenvironment, modulate antitumor immune responses, and influence clinical outcomes in cancer patients. Recent studies have expanded our understanding of the mechanisms underlying platelet-immune interactions in cancer, including antigen presentation, immune cell activation, and immunosuppressive signaling. Consequently, platelet-based and platelet-targeted therapies have emerged as promising strategies for enhancing antitumor immunity and improving responses to immunotherapy. However, specifically targeting tumor-educated platelets while minimizing adverse effects, particularly bleeding complications, remains a major challenge. In this review, we summarize the current evidence supporting the dual role of platelets in cancer immunity and discuss how engineered platelets may be leveraged to optimize therapeutic outcomes, highlighting their potential clinical applications and the integration of platelet-targeted approaches into next-generation cancer immunotherapies.