Prostate-Specific Membrane Antigen Expression in Neovasculature of Glioblastoma Multiforme

BACKGROUND: Glioblastoma (GBM) is the most malignant brain tumor with a poor prognosis that can be very difficult to cure, and the current treatment options have no optimal outcomes. Hence, it is essential to find new treatment modalities. Histologically, this tumor has high microvascular density that makes it desirable for vascular target agent drugs. Prostate-specific membrane antigen (PSMA) is a novel antigen with unique features that expresses in the vascular endothelium of some malignant tumors. MATERIALS AND METHODS: Formalin-fixed paraffin-embedded tissues from sixty patients who underwent GBM tumor resection from 2012 to 2016 were evaluated for the expression of PSMA by immunohistochemistry. Sections were also assessed for the extent and intensity of endothelial staining in tumor microvessels and for clinicopathologic factor correlation. RESULTS: A considerable PSMA expression level was detected in 66% of the cases, and the intensity was strong and moderate in 63%. There was no significant correlation neither between PSMA expression with tumor site, presence of necrosis, and endothelial proliferation nor with age and sex. CONCLUSION: The expression of PSMA in GBM, as observed in the current study, may suggest a new role of PSMA-targeted therapy and indicate more investigations focused on complementary treatment strategies that specifically target tumor vasculature.