Relationship between expression of PD-L1 and tumor angiogenesis, proliferation, and invasion in glioma.

Programmed death ligand 1 (PD-L1) is highly expressed in many cancers. We investigated the expression of PD-L1 and its relationship with vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 and KI-67 expression in 64 patients with primary glioma. The expression rate of PD-L1 in glioma patients was 78.12%. PD-L1 levels correlated with the tumor grade (p = 0.013), VEGF status (p = 0.002) and KI-67 status (p = 0.002). In addition, PD-L1 levels correlated positively with VEGF (r = 0.314, p = 0.011) and KI-67 (r = 0.391, p = 0.001) levels when the data were treated as continuous variables. This is the first report suggesting that PD-L1 is important for glioma angiogenesis and proliferation. Thus, further research should be conducted to assess the combination of targeted VEGF therapy and anti-PD-L1 immunotherapy for the treatment of glioma.