Uterine myoma in postmenopause: a comparison between two therapeutic schedules of HRT

It is still controversial whether hormone replacement therapy (HRT) can affect the onset of uterine myomas or their growth in postmenopause. It is likely that some therapeutic schedules can influence the myometrial growth differently, due to a more potent stimulation of the uterine receptors. The aim of the present study is to evaluate the effects of two different hormonal treatment schedules on the risk of uterine myoma onset or progression.

In a 2 year prospective randomised study we compared an oral cyclic association of oestradiol valerate and cyproterone acetate versus a sequential combination of transdermal E(2) and per oral medrossiprogesterone acetate on 240 postmenopausal women with and without uterine myomas.

Among the patients without uterine myomas treated with the transdermal-oral combination we noted the onset of myomas in 5% of cases after 24 months of treatment, while no new uterine formation was observed for the orally treated women (P<0.01). Among the patients with uterine myomas at the beginning of the study, in the group transdermally treated we found a mean increase in myoma volumes of 25.3% in the following 24 months, which was significantly different compared with the initial volume of myomas. On the other hand, women treated with the oral combination showed no significant modification of myoma volumes at the end of the study.

Percutaneous-oral schedule of HRT seems to affect the growth of uterine myomas more than a single oral combination of oestradiol valerate and cyproterone acetate.