Prostate-specific membrane antigen expression in clear-cell renal cell carcinoma: An angiogenic marker with clinicopathologic significance

Abstract

Background Clear-cell renal cell carcinoma (ccRCC) represents the majority of renal neoplasms with usual late presentation. Metastasis of ccRCC is very common owing to the vascular nature of this tumor. Identifying markers that could predict tumor behavior and metastatic potential is crucial to improve patient prognosis. Prostate-specific membrane antigen (PSMA) is a recently identified vascular marker that is expressed in many cancer types. This study aimed at evaluation of its clinicopathologic role in ccRCC. Materials and methods A total of 40 cases of ccRCC were recruited and subjected to immunohistochemical staining for PSMA. Statistical analysis was performed to assess its expression and its relationship with different clinicopathologic parameters. Results PSMA expression was positive in 72.5% of all cases. High expression was detected in 52.5% of cases, with positive correlation with high tumor grade (P=0.01), stage (0.04), and lymphovascular invasion (P=0.03). PSMA expression was positive in 83.3% of cases of tumor thrombus tissue, and 50% of these cases showed high expression. Two (50%) cases of metastatic lesions showed low positive expression for PSMA with high PSMA expression in 75% of the corresponding primary lesions. Conclusion PSMA is specifically expressed in the vasculature of ccRCC, showing a positive correlation with poor prognostic parameters. This renders PSMA as a promising prognostic marker and therapeutic target.