Tumor Vasculatures: A New Target for Cancer Immunotherapy

Immune cells rely on a functional vascular network to enter tissues. In solid tumors, blood vessels are abnormal and dysfunctional and, thus, immune effector cell infiltration is impaired. Although normalizing the tumor vasculature has been shown to improve the efficacy of cancer immunotherapies, recent studies suggest that enhanced immune stimulation also, in turn, improves tumor vascular normalization. Thus, this new paradigm of immune system–tumor vasculature mutual reprogramming opens the possibility of identifying new cancer treatment strategies that combine vascular targeting and immunotherapies. Here, we highlight current evidence supporting immune system–tumor vasculature crosstalk and outline how this relationship can provide new rationales for developing more effective combination immunotherapy strategies for treating human cancers.