Effect of hormone replacement therapy on postmenopausal endometrial bleeding.

The aim of the study was to determine the effect of postmenopausal hormone replacement therapy (HRT) (treatment using estrogen only and sequential and continuous combined estrogen-progestogen treatment) on endometrial bleeding and histological changes of the endometrium. In a six-year period (2000-2005), 5893 patients were given care and the incidence of postmenopausal uterine bleeding was detected in groups of patients having and not having received hormonal treatment at the Menopause Outpatient Unit of the authors' department. In the case of bleeding, fractioned abrasion was performed and the samples were analyzed histologically. Among the postmenopausal patients who had not been given hormonal treatment, the incidence of bleeding episodes was significantly higher as among those having received hormonal treatment. In the samples, findings of proliferative endometrium occurred significantly more often in case of non-treated patients and those treated with sequential combined hormone therapy compared to patients receiving continuous combined hormone therapy. Although it was statistically not significant, hyperplasia simplex and complex together showed a tendency of reduced incidence in patients medicated by continuous combined treatment. These findings suggest that continuous combined hormonal treatment started at the right time (even before the menopause) may reduce the chances of the development of hyperplasia. A significantly higher incidence of hyperplasia was noted in patients using estrogen treatment only. It is possible that unopposed estrogen treatment further engraves an already diagnosed endometrial hyperplasia. In the group having received hormonal treatment, no complex hyperplasia accompanied by atypia occurred, only hyperplasia simplex was diagnosed in these cases. As a result of continuous reliance on combined preparations, the endometrium had become atrophied, therefore the chance of hyperplasia-related changes and of bleeding as a side effect decreased significantly. According to the authors' experience, hormonal treatment does not pose a risk to the development of endometrial carcinoma; on the contrary, continuous combined preparations appear to reduce the risk of hyperplasia and, indirectly, the chances of the development of adenocarcinoma.