Endoglin (CD105) expression in human renal cell carcinoma

OBJECTIVE To evaluate the prognostic potential of endoglin (CD105) expression in human renal cell carcinoma (RCC), as endoglin is a cell membrane glycoprotein expressed in tumour‐associated vascular endothelium and a marker of angiogenesis; intratumoral microvessel density assessed by endoglin staining has prognostic significance in some neoplasms. PATIENTS AND METHODS Tumour samples from 210 patients with RCC (168 conventional), diagnosed between 1982 and 1997, were assessed using the tissue microarray technique with immunohistochemical staining for endoglin. The expression of endoglin was related to clinical variables and survival. RESULTS Of the tumours, 75% expressed endoglin, and in conventional RCC the expression was inversely correlated to the Tumour‐Node‐Metastasis (TNM) stage (P = 0.008) and nuclear grade (P = 0.01). There was no correlation between endoglin expression and gender, age, tumour size or cell type. Patients with conventional RCC and high endoglin expression had a more favourable prognosis than those with tumours with lower expression (P = 0.04). A multivariate analysis of prognostic factors showed that TNM stage and nuclear grade were independent predictors of prognosis. Endoglin expression did not add further prognostic information. CONCLUSION These results indicate that endoglin expression is inversely related to stage and grade in RCC, and that it is associated with prognosis.