Hormonal Substitution Treatment, Proliferation of theBreast and the Risk of Breast Cancer

Overview

Objective:
The objective of the study was to investigate the changes of histopathological andimmunohistochemical parameters of breast tissue among the HRT users.Design: Prospective, pilot study.Setting: Departments of Gynecology and Obstetrics, Pathology and Radiology of the 2nd MedicalSchool, Charles University and the Teaching Hospital Motol, Praha 5, Czech Republic.Methods: The samples of breast issue were obtained by core cut biopsy and during the breastsurgery procedures in the study group of HRT users (no=48) and in the control group of womenwithout HRT (n=22). Proliferation index (Ki-67), expression of ERB2 oncoprotein and hormonalreceptors (ER, PR) were examined in the breast tissue in addition to routine histopathologicalexaminations.Results: We did not record increasing freqeuncy of proliferative and precancerous lesions in thegroup of HRT users. Ki-67 expression was very low both in HRT users and in the control group ofwomen. The values of estrogen receptors expression in breast tissue samples of women with HRTwere similar to the findings in the normal breast. The values of progesterone receptor expressionwere higher among the HRT users then non-users, but it can be considered as a normal responseof breast tissue to hormonal influence. Expression of ERB protein in HRT users was similar tothat found in non-users.Conclusion: The findings indicate that HRT has not increased the proliferation rate of the breasttissue in our study group, so this mechanism certainly does not increase the risk of breast cancer.

Key words:
HRT, Ki-67, breast tissue proliferation, breast cancer risk