Prostate-specific membrane antigen expression in endothelial cells of renal tumor-associated neovasculature and risk of recurrence for renal cell carcinoma.

Abstract

377 Background: PSMA is highly expressed in prostate epithelial cancer cells and used not only for diagnostic but also for therapeutic purposes. Despite its name, PSMA is not specific in prostate cells and is also expressed endothelial cells within the neovasculature of other tumors including renal cell carcinoma. PSMA is particularly the correlation of increased PSMA expression with prostate cancer aggressiveness, but is unknown in renal cell carcinoma patients. Here we estimate whether PSMA expression in endothelial cells of renal tumor-associated neovasculature is associated with pathological venous invasion and prognosis for patients after renal tumor surgery. Methods: A total of 45 patients who underwent radical or partial nephrectomies performed at our institution were included in this study. We investigated pathological venous invasion and PSMA expression in tumor-associated vessels around renal cell carcinoma by immunostaining using removed tumor tissue. The PSMA immunostain was evaluated in tumor-associated vessels according to the staining intensity and divided into three groups: weak, moderate, and strong, respectively. Results: Higher PSMA expression group is increased the percentage of patients with histologically observed venous invasion. The level of PSMA immnostain were detected in 18 cases at weak, 11 at moderate, 16 at strong. Ten patients after surgery had recurrence during the observation period, and the prognosis was worse in the group with strong PSMA expression in tumor-associated vessels around renal cell carcinoma. Conclusions: PSMA expression in endothelial cells of renal tumor-associated neovasculature may be a novel prognostic factor for renal cell carcinoma.