Maintenance of increased Bcl-2 expression in uterine leiomyomas after GnRHagonist therapy

OBJECTIVE: To compare the immunohistochemical expression of Bcl-2 in uterin e leiomyomas in patients undergoing myomectomy or hysterectomy with and wit hout preoperative treatment with the gonadotropin-releasing hormone recepto r agonist (GnRH-a) leuprolide acetate (LA). STUDY DESIGN: Retrospective case-control study. Seventeen patients with sym ptomatic uterine leiomyomata were included. Of the 17 patients, 7 were trea ted with LA (3.75 mg) in three monthly doses prior to myomectomy or hystere ctomy. Ten patients who did Mot receive LA and underwent hysterectomy for l eiomyomas served as controls. Formalin fixed, paraffin-embedded archival ti ssue from 17 leiomyomas were immunostained with a monoclonal antibody again st Bcl-2 protein. Positivity was scored semiquantitatively on a three-tier scale. RESULTS: Immunostaining for Bcl-2 protein was intense (2-3+) ii 7 LA-treate d and 10 untreated leiomyomas but T-I,IIS scarce (0-1+) in normal myometria l smooth muscle. CONCLUSION: Abundant expression of Bcl-2 protein may be responsible for the growth of leiomyomas by preventing apoptotic cell death. Its increased exp ression is maintained in GnRH-a-treated leiomyomas.