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 therapy, an estrogen-progestin combination and tibolone, on uterine myomas in menopausal women. Study design: Thirty-eight menopausal women with one or more uterine myomas were randomized to treatment with a transdermal system continuously releasing estradiol 50 μg/day combined with oral medroxyprogesterone 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 examination and abdominal/transvaginal ultrasonography were performed before entering the study and at 3, 6 and 12 months of treatment. At each ultrasonography the overall uterine volume was determined as well as the size of each myoma and the endometrial thickness and characteristics. Results: No statistically 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-progestin group, whereas no such increase occurred in the patients treated with tibolone. Also, the mean endometrium width increased significantly from baseline to the end of treatment in the estrogen-progestin group, but not in the tibolone group. Conclusions: Tibolone seems a valid alternative in menopausal patients with uterine myomas as it provides adequate relief from menopausal symptoms and avoids volume increase of the uterus and myomas. Copyright (C) 2000 Elsevier Science Ireland Ltd.