Beyond Hemostasis: Platelets as Drivers of Immune Suppression in Cancer

Despite their primary role in hemostasis, pre-clinical evidence suggests that platelets also promote cancer progression. Mechanistically, platelets deliver tumor-supportive signals through direct contact or secreted mediators that can promote several cancer hallmarks, including angiogenesis, metastasis, and more recently, immune suppression. As the roles of platelets in cancer become ever more established in pre-clinical studies, the rationale for testing antiplatelet drugs in patients has also grown and now needs to be considered in the wider context of cancer immunotherapy. This review highlights recent mechanistic discoveries demonstrating how platelets promote tumor immune evasion and discusses how targeting platelets may synergize with cancer therapy.