Immunohistochemical Detection of Prostate Specific Membrane Antigen in Prostate Tumors

Abstract

This retrospective analytical case control study was carried out in Omdurman Teaching Hospital and Sudan University of Science and Technology- College of Medical Laboratory Science during the period from October 2017 to January 2018. It aimed to detect the expression of prostate specific membrane antigen in prostate tumors by immunohistochemistry. Forty previously diagnosed formalin-fixed paraffin-embedded prostate tissue blocks were collected, 20 (50%) of them were diagnosed benign prostatic hyperplasia as control group and the other 20 (50%) were prostatic adenocarcinoma with different grades and Gleason score as case group. Blocks were cut by a microtome and 4 μm sections were obtained. Sections were stained by enhanced polymer one step method and examined under the microscope for PSMA expression. Then results were analyzed by SPSS program version 14.0. The age of the study group ranged between 55-95 years and the mean age was 72 years. Of the 20 prostatic adenocarcinomas, 5 (25%) were well differentiated adenocarcinoma, 5 (25%) were moderately differentiated and 10 (50%) were poorly differentiated. Eighteen (45%) out of the 20 benign prostatic hyperplasia samples were negative for PSMA and 2 (5%) were positive, while 17 (42.5%) out of the 20 prostatic adenocarcinoma were positive and 3 (7.5%) showed negative expression. The study revealed a significant difference in the expression of PSMA between benign prostatic hyperplasia and prostatic adenocarcinoma as it is overexpressed in the latter (P value=0.000). It also revealed that the relation between the expression of PSMA and grade of cancer was statistically significant; as the expression increases with higher grades (P value=0.005). These findings conclude that PSMA is an important diagnostic and prognostic marker for prostate cancer.