The value of epithelial membrane antigen overexpression in hyperplastic and malignant endometrium and its relationship with steroid hormone receptor expression.

ABSTRACT

The aim of this study was to evaluate the value of epithelial membrane antigen overexpression (EMA OE) in benign, hyperplastic and neoplastic endometrium and to analyze its association with estrogen and progesterone receptors (ER, PR) immunohistochemistry, tumor grade and myometrial invasion in patients with endometrial carcinoma (EC). The OE of EMA was analysed immunohistochemically in nine patients with benign endometrium (BE), in 18 patients with atypical complex endometrial hyperplasia (ACH) and in 29 patients with EC. EMA OE was present in 13 of 29 patients (44.8%) with EC, in two of 18 patients (11.1 %) with ACH, and in none of nine patients with BE (p < 0.05). EMA OE of endometrial carcinoma was statistically correlated with the International Federation of Gynecology and Obstetrics (FIGO) grade (G1 vs G2 and G3, p < 0.05) and depth of myometrial invasion (< 1/2 vs > 1/2, p < 0.05). EMA OE was significantly associated with PR negativity (p < 0.001). However it did not show any association with ER immunohistochemistry (p = 0.14). PR immunohistochemistry had significant correlations with FIGO grade (p < 0.001) and depth of myometrial invasion (p < 0.05) but ER loss showed a nearly significant association only with advanced FIGO grade (p = 0.054). In conclusion, EMA shows increased expression as the lesion progresses to malignancy and can also aid discrimination between hyperplastic and neoplastic states. The correlation of imunohistochemical findings with tumor grade and myometrial invasion could help in predicting behavior of the tumor and planning treatment in patients with endometrial carcinoma.