ABSTRACT
An immunohistochemical study was carried out with monoclonal antibodies to estrogen receptors (Ers), Ki-67, BCL-2, P53 and human papillomaviruses (HPV) of normal cervix (7 cases), cervical leukoplakia (5 cases), CIN I (7 cases) and CIN II-III (6 cases). Correlations were also investigated between hyperestrogenemia and molecular changes in the exocervix. About two thirds of patients with leukoplakia and precancerous changes had clinical signs of hyperestrogenemia which led to proliferation of estrogen-sensitive parabasal cells. Due to neoplastic epithelial transformation the number of cells with Ki-67, P53 and HPV positive reactions in the nuclei increased, while Ers and BCL-2 expression decreased. Because active proliferative parabasal cells are needed for HPV replication we consider hyperestrogenemia as a factor stimulating development of neoplastic changes in the uterine cervix.