Correlation of Endothelin-1 expression in prostate cancer withtumor prognostic markers: An Iranian experience

Background:The importance of Endothelin-1 expression in tumor aggressiveness and metastatic potentialhas been confirmed in a variety of different organs tumors including prostate gland as well asrecent trials of targeted therapy. As the prostate adenocarcinoma is one of the most commonmalignant tumors in males, looking for a marker with predictive value of aggressiveness andmetastatic potential in an apparently localized cancer in initial needle biopsy specimens couldhelp the clinicians to make the more appropriate decision for treatment planning and perhapschoosing targeted therapy.Materials and Methods:In a cross sectional study 83 patient who underwent radical prostatectomy were studied in 2groups: 43 with extraprostatic extension (EPE) and 40 without EPE. Immunohistochemicalstaining with Endothelin-1 was performed on Formalin Fixed Paraffin Embedded (FFPE)blocks of their pre-operative needle biopsies.Results:Endothelin-1 was positive in 11(26%) of 43 patients with no extraprostatic extension, butshowed increased expression in cases with extraprostatic extension up to 29 (72%) of 40patients (P<0.001). Endothelin-1 positive group showed higher serum PSA levels thanEndothelin-1 negative group (44.6 ± 10.2 ng/ml vs. 18.6 ± 6.8 ng/ml) with P=0.039.Thismarker 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 (P<0.001). The marker was positive in9(32.1%) of 28 patients with Gleason ´s score =6, 18(54.5%) of 33 patient with Gleason ´sscore =7, 10(58.8%) of 17 patients with Gleason´s score=8, 2(50%) of 4 patients withGleason´s score=9 and in 1(100%) patient with Gleason ´s score 10 (P=0.261).Conclusions:These results supported correlation of Endothelin-1 expression in needle biopsy specimenswith extraprostatic extension of tumor in radical prostatectomy specimens, perineurialinvasion and serum PSA levels at the time of diagnosis; But didn´t show correlation betweenexpression of Endothelin-1 and tumor Gleason´s score.