Comparison of the effect of gonadotropin-releasing hormone agonist and dopamine receptor agonist on uterine myoma growth. Histologic, sonographic, and intra-operative changes.

Objective: To investigate the effect of 2 medications; Diphereline and Cabergoline, on uterine leiomyoma growth, and its histologic, sonographic, and intra-operative changes.

Methods: In an effort to treat large uterine leiomyoma in symptomatic patients in the Gynecology Clinics of the Alzahra Teaching Hospital of Tabriz University of Medical Sciences, Tabriz, Iran, from September 2007 to November 2008, 60 candidates randomized to receive Diphereline 3.75 mg, 4 times every 28 days (group I), and Cabergoline 0.5 mg, once a week for 6 weeks (group II), were included in this study. Clinical symptoms, feasibility of intra-operative dissection, intraoperative complications, sonographic, and pathologic characteristics of the tumor were evaluated.

Results: Thirteen patients from group I, and 10 patients from group II underwent surgery. There was a significant difference between the groups in the rate of lymphocyte infiltration (p=0.003), but not in other pathologic features. In both groups, the mitotic index was between 0-10. While there was no significant difference between the groups in the number (p=0.30), and volume of leiomyomas (p=0.65), however, changes in the uterine artery circulation was significant (p=0.001 [group I], p=0.026 [group II]). In addition, there was a significant difference between the groups for intra-operative hemorrhage and adhesion of leiomyomas to the uterine wall.

Conclusion: This study found that Cabergoline is as effective as Diphereline in the shrinkage of myomas, accompanied by improvement in the sonographic, clinical, and intra-operative outcomes without any adverse pathological changes, and could be a good medical regimen as an adjunct to surgical management.