OBJECTIVETo investigate the different expressions of endothelin-1 ET-1) in prostate cancer (PCa) and benign prostatic hyperplasia (BPH) tissues and their clinical significance.

METHODSA total of 36 BPH and 44 PCa specimens were examined for the expression of ET-1 by immunohistochemical technique (Elivision plus method). The staining intensity for ET-1 was assessed by light microscopy on a scale from "-" to "+ + +".

RESULTSPositive immunoreactivity was found in BPH and PCa, with a positive rate of 100%. Positive staining was located mostly in the cytoplasm of glandular epithelia and smooth muscle cells of both BPH and PCa and was noted in all stroma vascular endothelial cells. These were no significant differences in the intensity of positive staining for ET-1 between the groups of BPH and PCa (P > 0.05), bone metastasis (BM) and non-BM (P > 0.05), and highly and moderately differentiated PCa (P > 0.05), but the staining intensity for ET-1 was significantly higher in the poorly than in the highly and moderately differentiated PCa (P < 0.01).

CONCLUSIONET-1 has a high expression and the localization is the same in both BPH and PCa. It is involved in the development and progression of BPH and PCa.