THE ROLE OF PROSTEIN (P501S) AND GATA3 IMMUNOSTAINING IN DIFFERENTIATING POORLY DIFFERENTIATED PROSTATIC CARCINOMA FROM HIGH GRADE UROTHELIAL CARCINOMA

Abstract

Background: Prostatic cancer (PC) is now recognized as one of the common medical problems facing the male population accounting for 33% of all malignant tumors. In Egypt, cancer bladder constitutes 30% of all cases attended at the National Cancer Institute with an overall incidence rate of 13.5/100,000 individual. The histological distinction between poorly differentiated prostatic adenocarcinoma and high grade urothelial carcinoma (UC) can be difficult. This distinction is important due to prognostic and therapeutic consideration. Aim of work: To differentiate between poorly differentiated prostatic adenocarcinoma and high grade UC immunohistochemically, using prostein (P501s) and GATA3.
Methods: Prostein (P501s) and GATA3 expressions were retrospectively analysed by immunohistochemistry in two groups. The first group consisted of 42 paraffin-embedded specimens of poorly differentiated prostatic adenocarcinoma and 45 paraffin-embedded specimens of high grade urothelial carcinoma (documented group). The second group consisted of 8 cases of prostatic biopsies and 5 cases of bladder biopsies in which the origin of the carcinoma couldn’t be assessed (problematic group). The expressions were correlated with clinicopathological variables.
Results: The immunoexpression of prostein was positive in 40/ 42 (95.3%) of poorly differentiated prostatic adenocarcinoma while showed negative staining in 100% of cases of high grade urothelial carcinoma (documented group) with a statistically highly significant correlation (p<0.0001). There is statistically significant an inverse correlation between prostein immunoexpression and the Gleason score for poorly differentiated prostatic adenocarcinoma (documented group) (p value = 0.02). GATA3 was positive in 44/45 (97.8%) of high grade urothelial carcinoma while negative in 100% of poorly differentiated prostatic adenocarcinoma (documented group) with a statistically highly significant correlation (p <0.001). There is an inverse correlation between the depth of invasion of high grade urothelial carcinoma and GATA3 immunoexpression and it was statistically significant (p =0.01). Prostein sensitivity and specificity for poorly differentiated prostatic adenocarcinoma (documented group) was 94.5% and 100% respectively, while the sensitivity of GATA3 for high grade urothelial carcinoma (documented group) was 88.9% and specificity was 100%.
Conclusions: Prostein (P501s) and GATA3 are useful markers in differential diagnosis between poorly differentiated prostatic adenocarcinoma and high grade urothelial carcinoma.
Keywords: Prostein(P501s) – GATA3 – urothelial carcinoma of urinary bladder – prostatic carcinoma Immunohistochemistry (IHC)