A randomized study of the effects of tibolone and transdermal estrogen replacement therapy in postmenopausal women with uterine myomas

Objective: To evaluate the effects of two types of hormone replacement ther apy, an estrogen-progestin combination and tibolone, on uterine myomas in m enopausal women. Study design: Thirty-eight menopausal women with one or mo re uterine myomas were randomized to treatment with a transdermal system co ntinuously releasing estradiol 50 mu g/day combined with oral medroxyproges terone acetate (MPA) 10 mg/day for 12 days/month or tibolone tablets 2.5 mg /day. The scheduled duration of both treatments was 12 months. Physical exa mination and abdominal/transvaginal ultrasonography were performed before e ntering the study and at 3, 6 and 12 months of treatment. At each ultrasono graphy the overall uterine volume was determined as well as the size of eac h myoma and the endometrial thickness and characteristics. Results: No stat istically significant difference was detected between the two groups at any time during treatment. However, within-group analysis showed a significant increase of uterine volume and of myoma number and size in the estrogen-pr ogestin group, whereas no such increase occurred in the patients treated wi th tibulone. Also, the mean endometrium width increased significantly from baseline to the end of treatment in the estrogen-progestin group, but not i n the tibulone group. Conclusions: Tibolone seems a valid alternative in me nopausal patients with uterine myomas as it provides adequate relief from m enopausal symptoms and avoids volume increase of the uterus and myomas. (C) 2000 Elsevier Science ireland Ltd. All rights reserved.