Comparative immunohistochemical study of endometrioid and serous papillary carcinoma of endometrium

The aim of this study was to determine whether immunohistochemical analysis of molecular parameters can provide an alternative method for classification of endometrial cancer cases according to their aggressiveness.

Sixty-four cases of endometrial carcinoma were assigned to three groups: group I--28 cases of endometrioid well and moderately differentiated (G1-G2) carcinoma; group II--14 cases of endometrioid poorly differentiated (G3) carcinoma; group III--22 cases of serous papillary endometrial cancer. Immunohistochemistry was used to determine the existence of estrogen receptors (ER), progesterone receptors (PR), and the expression of bcl-2, p53, HER-2/neu and Ki-67.

There was a significant difference in the immunohistochemical profile of the studied molecular parameters comparing the three study groups. The endometrioid G1-G2 cases (group I) were characterized by increased immunoreactivity for ER and PR (85.7% and 78.6%, respectively), increased immunoreactivity for bcl-2 (42.8%) and low expression of p53 (14.3%) and HER-2/neu (14.3%). In contrast to group I cases, the serous papillary endometrial cancer cases (group III) were characterized by immunonegativity for ER, PR and bcl-2 and high immunoreactivity for p53 (81.8%) and HER-2/neu (45.4%). The endometrioid G3 cases (group II) demonstrated an intermediate immunoprofile, characterized by immunonegativity for ER, PR and HER-2/neu, low immunoreactivity for bcl-2 (7.1%) and high expression of p53 (57.1%). The expression of Ki-67 did not differ significantly comparing the different cases of endometrial cancer.

This study provides evidence that the immunohistochemical analysis of endometrial carcinoma differentiates between different grades and histological types, thus being useful in the distinction of high risk cases.