EXPRESSION OF MIB-1 (PARAFFIN KI-67) AND AGNOR MORPHOLOGY IN ENDOMETRIAL ADENOCARCINOMAS OF ENDOMETRIOID TYPE

Cell kinetic information is an important adjuvant to histologic gradin g and to stage in some malignant tumors. Some studies have shown that in endometrial carcinomas, flow cytometric S-phase correlates with kno wn prognostic parameters. In the current study, the expression of silv er-stained nucleolar organizer regions (AgNORs) and MIB-1 (ki-67-paraf fin) was assessed on paraffin sections in 112 endometrial adenocarcino mas of endometrioid type (EC) (49 hormone users, 63 nonusers). The AgN OR morphology correlated significantly with MIB-1, mitotic count, and nuclear and architectural grade, but not with stage or previous hormon e treatment. MIB-1 correlated with all the above parameters except myo metrial invasion and stage. Only myometrial invasion and stage correla ted with short-term outcome; in such cases tumors from hormone users a nd nonusers were pooled. The median MIB-1 value was significantly lowe r in EC from hormone users compared with EC from nonusers; moreover, w hen tumors from hormone users and nonusers with poor outcome were exam ined separately only 29% (four of 14) of the tumors expressed MIB-1 le ss than the medians in the respective groups, indicating that a progno stic cutoff point may be different in the two groups. Because hormone replacement therapy is very common, this observation has implication f or future studies of growth fraction in EC. This is the first study to show that AgNOR morphology is significantly correlated with other mar kers of growth fraction and histologic grade.