Cathepsin D expression in renal cell cancer-clinical implications.

Abstract

Whereas the expression of Cathepsin D (Cath D) is suggested to enhance the biological aggressiveness of human malignancies, its role in renal cell carcinoma (RCC), however, has not been investigated. By tissue microarray analysis, tumor and benign tissue samples from 176 RCC patients were investigated for Cath D expression by immunohistochemistry and Western blots. Expression levels were correlated to clinical variables and to the postoperative outcome. High Cath D expression levels were detected in 29%/9% of tumor and benign tissue samples, respectively (p < 0.0001). In case of a high vs. low Cath D expression level, development of distant metastases was observed in 12% vs. 88% of cases (p < 0.05). With a median follow-up of 50 (2-146) months, high level Cath D expression was correlated with an improved long-term survival when compared with patients presenting with decreased expression [median long-term survival: 82 vs. 53 months in case of a high vs. low expression level] (p < 0.05). The Cath D staining pattern predicted a reduced risk for metastatic spread and tumor dependent death, hereby indicating its role as a biological variable revealing additional prognostic information for renal cell cancer patients. Increased expression of Cath D in tumor vs. benign tissue samples might indicate a role for the development and progression of RCC.