Cell cycle analysis and detection of proliferative cell nuclear antigen of the endometrium after hormone replacement therapy

Background: To understand the effect of sequential combined hormone replacement therapy (HRT) on the postmenopausal endometrium. Methods : Sonographic endometrial thickness. endometrial histopathology, flow cytometric cell cycle analysis and the level of proliferative cell nuclear antigen (PCNA) were studied. Results: One hundred and thirty-eight postmenopausal women were enrolled in this study. Among which, 97 women had their endometrium being adequately obtained: the most frequent type of histopathology was normal endometrium (91.8%). Endometrial hyperplasia was found in seven patients (7.2%), including typical simple hyperplasia (n = 1, 1%), focal simple hyperplasia (n = 5, 5.2%) and complex hyperplasia without atypia (n = 1, 1%). The proliferative fractions (PF S Plus G(2) - M phase) of cells from normal and hyperplastic endometrium of menopausal women after HRT were 8, 18 and 8.95%, respectively, which were lower than those from 29 premenopausal women without HRT. The level of PCNA of normal and hyperplastic endometrium in postmenopausal women after HRT was about 80 and 84%, respectively, of that from premenopausal endometrium. Conclusions: Our study showed the PF of the cell cycle and the level of PCNA were not increased in the menopausal endometrium under HRT as compared to the premenopausal controls. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.