Expression of MIB-1 in Endometrial Adenocarcinoma: Correlation with p53 Protein Expression and Histologic Prognostic Factors

Kim, Mi Jin; Shim, Young Ran; Kim, Dong Sug

Abstract

The evaluation of the proliferative potential of malignant neoplasm is of major interest for predicting their biological behavior. MIB-1, a monoclonal antibody against the Ki-67 antigen, is a marker of cell proliferation, which is widely applied to human cancers recently. To assess the growth potential of uterine endometrial carcinoma, we performed immunohistochemical staining of MIB-1 in 34 cases of endometrial adenocarcinoma (endometroid type) from the paraffin sections. We evaluated its correlation with p53 overexpression and known prognostic factors including FIGO grade, nuclear grade, myometrial invasion, and estrogen and progesterone receptors. As a result, the MIB-1 labelling index was significantly correlated with FIGO grade, nuclear grade and myometrial invasion (p<0.05) and there was no significant correlation between MIB-1, ER or PR status. The expression of p53 protein showed significant correlation with FIGO grade and nuclear grade (p<0.05) and there was no significant correlation among p53 protein, myometrial invasion, ER and PR status. The MIB-1 labelling index revealed striking difference between p53 positive and p53 negative group (p<0.05). We concluded that MIB-1 labelling index is associated with poor prognostic parameter in endometrial adenocarcinoma, and may be a useful marker for predicting tumor of high grade and deep myometrial invasion, if MIB-1 labelling index is more than 50% and is accompanied by p53 overexpression.