EXPRESSION OF C-ERBB-2 PROTEIN AND EPIDERMAL GROWTH-FACTOR RECEPTOR IN ENDOMETRIAL CARCINOMAS - CORRELATION WITH CLINICOPATHOLOGICAL AND SXSTEROID-RECEPTOR STATUS

Background. The c-erbB-2 (HER-2/neu) protein is a membrane glycoprotei n growth factor receptor showing molecular homology with the epidermal growth factor receptor (EGFR). In endometrial carcinomas, little is k nown about the relationship between the expression of c-erbB-2 protein and that of EGFR. Methods. The immunohistochemical reactivity of mono clonal antibodies against both of these proteins was examined in 34 en dometrial carcinomas, and the presence or absence of correlation with the clinicopathologic features or with the immunohistochemical express ion of sex steroid receptors (estrogen receptor [ER] and progesterone receptor [PR]) was analyzed. Results. Of the 34 patients, 22 (64.7%) h ad c-erbB-2 protein-positive and EGFR-negative tumor, and 8 (23.5%) ha d tumor positivity for both proteins. Four patients had tumors negativ e for both proteins. ER or PR positivity was found in 24 (70.6%) of th e 34 patients. Intense immunostaining for c-erbB-2 protein was found i n 5 (14.7%) of the 34 patients but was not correlated with the stage o r grade of differentiation in endometrial carcinoma. However, expressi on of EGFR in addition to c-erbB-2 protein was more frequently observe d with advancing stage of disease and was inversely correlated with th e grade of differentiation and with the expression of ER or PR of the tumor. Conclusion. The expression of EGFR, in addition to that of c-er bB-2 protein, is an important event that presumably is linked with pro gression or with a poorly differentiated state of endometrial carcinom as.