IMMUNOHISTOCHEMICAL ANALYSIS OF RAS ONCOGENE PRODUCT P21 IN HUMAN ENDOMETRIAL CARCINOMA

Monoclonal antibody rp-28 directed against the ras gene product p21 ha s been used to evaluate ras p21 expression in endometrial lesions. End ometrial cancer showed a variable reactivity according to histological type: in well differentiated adenocarcinoma 63% were positive (12/19) ; in moderately differentiated adenocarcinoma 53% were positive (8/15) ; in poorly differentiated adenocarcinoma 40% were positive (2/5). The staining intensity of ras p21 seemed to be stronger in the more diffe rentiated types of endometrial carcinoma. In endometrial carcinoma wit h premenopausal women, 27% were positive (3/11), and with postmenopaus al women 71% were positive (20/28). The difference between premenopaus al and postmenopausal groups was statistically significant (Mantel-Hae nszel procedure, M-H(chi)2 = 6.765, P < 0.01). The results suggest the existence of different carcinogenetic mechanisms in these two groups of endometrial cancer.