Effects of treatment with gonadotropin releasing hormone agonist on the uterine leiomyomata structure

Objective. Our aim was to study the effects of the gonadotropin releasing hormone agonist on the uterine leiomyoma of infertile women. Material and methods. Sixty-seven nulliparous women (aged 24-39 years) with uterine leiomyomas, underwent ultrasonographic study of leiomioma volume, and were divided in two groups. Thirty-one had nodes greater than 300 cm(3) and were treated with goserelin 3.6 mg every 28 days for 6 months (group I); the other 36 patients did not receive medication (group II or control group). Sixteen patients from group I had less than or equal to 36% (median) reduction of the leiomyoma volume (subgroup Ia) and the other 15 women had reduction > 36% (subgroup Ib). All women underwent myomectomy. Results. The group with the greater leiomyoma reduction after treatment with goserelin (group Ib) showed a significantly lower percentage of ER+ when compared with group Ia and the control group. Group Ib had a significantly higher percentage of PR+ in relation to the control group, but not to group Ia. The number of blood vessels, AgNOR dots, and cells, and the amount of collagen were not different between the three groups studied. Leiomyomata reduction correlated negatively with the percentage ER+ cells, but positively with the PR+ cells, amount of collagen and number of blood vessels. No correlation was found between the number of AgNOR dots and cellularity. Conclusion. Our data strengthen the hypothesis that the uterine leiomyoma response to steroid hormones results from the presence of specific hormone receptors, and progesterone receptors may also play a role in the development of leiomyoma.