Correlation of Endothelin-1 expression in prostate cancer with tumor prognostic markers: an Iranian experience

Abstract

<h3>Background</h3> The importance of Endothelin-1 expression in tumor aggressiveness and metastatic potential has been confirmed in a variety of different organ tumors including prostate gland as well as recent trials of targeted therapy. As the prostate adenocarcinoma is one of the most common malignant tumors in males, looking for a marker with predictive value of aggressiveness and metastatic potential in an apparently localized cancer in initial needle biopsy specimens could help clinicians to make the more appropriate decision for treatment planning and perhaps choosing targeted therapy. <h3>Method</h3> In a cross sectional study, 83 patients who underwent radical prostatectomy were studied in 2 groups: 43 with extraprostatic extension (EPE) and 40 without EPE. Immunohistochemical staining with Endothelin-1 was performed on formalin fixed paraffin embedded (FFPE) blocks of their pre-operative needle biopsies. <h3>Results</h3> Endothelin-1 was positive in 11 (26%) of 43 patients with no extraprostatic extension, but showed increased expression in cases with extraprostatic extension up to 29 (72%) of 40 patients (<i>p</i><0.001). The Endothelin-1 positive group showed higher serum PSA levels than the Endothelin-1 negative group (44.6 ± 10.2ng/mL vs 18.6 ± 6.8ng/mL) with <i>p</i>=0.039. This marker was positive in 29 (67%) of 43 patients with perineurial invasion and so in 11 (27%) of 40 patients who didn't show perineurial invasion (<i>p</i><0.001). The marker was positive in 9 (32.1%) of 28 patients with Gleason's score=6, 18 (54.5%) of 33 patients with Gleason's score=7, 10 (58.8%) of 17 patients with Gleason's score=8,2 (50%) of 4 patients with Gleason's score=9 and in 1 (100%) patient with Gleason's score 10 (<i>p</i>=0.261). <h3>Conclusions</h3> These results supported correlation of Endothelin-1 expression in needle biopsy specimens with extraprostatic extension of tumor in radical prostatectomy specimens, perineurial invasion and serum PSA levels at the time of diagnosis, but didn't show correlation between expression of Endothelin-1 and tumor Gleason's score.