Endoglin expression in upper urinary tract urothelial carcinoma is associated with intravesical recurrence after radical nephroureterectomy

Objectives To evaluate the expression and prognostic significance of endoglin in patients with upper urinary tract urothelial carcinoma. Methods zArchival formalin‐fixed and paraffin‐embedded tissues from 99 cases of primary upper urinary tract urothelial carcinomas treated with nephroureterectomy were retrieved. Tissue microarrays were constructed with triplicate tumor samples and paired non‐neoplastic urothelium. Tissue microarrays were analyzed using immunohistochemistry for endoglin, and the associations between clinicopathological parameters and outcome were studied. Results Endoglin expression was significantly higher in the endothelium of upper urinary tract urothelial carcinomas than in paired benign urothelium ( P  < 0.001). Endoglin expression was not associated with pathological T stage or tumor grade, and it was not associated with increased hazard ratios for cancer‐specific mortality, tumor recurrence in the lymph node or distant metastasis. However, expression of endoglin was significantly associated with intravesical recurrence, when adjusting for other relevant clinicopathological variables ( P  = 0.015). Conclusions Endoglin is overexpressed in the endothelium of upper urinary tract urothelial carcinomas when compared with normal urothelium, and this overexpression seems to be associated with a higher risk of intravesical recurrence. Therefore, endoglin could be a biomarker for the prediction of intravesical recurrence, as well as a potential therapeutic target.