Maintenance of increased Bcl-2 expression in uterine leiomyomas after GnRH agonist therapy.

OBJECTIVE: To compare the immunohistochemical expression of Bcl-2 in uterine leiomyomas in patients undergoing myomectomy or hysterectomy with and without preoperative treatment with the gonadotropin-releasing hormone receptor agonist (GnRH-a) leuprolide acetate (LA). STUDY DESIGN: Retrospective case-control study. Seventeen patients with symptomatic uterine leiomyomata were included. Of the 17 patients, 7 were treated with LA (3.75 mg) in three monthly doses prior to myomectomy or hysterectomy. Ten patients who did not receive LA and underwent hysterectomy for leiomyomas served as controls. Formalin-fixed, paraffin-embedded archival tissue from 17 leiomyomas were immunostained with a monoclonal antibody against Bcl-2 protein. Positivity was scored semiquantitatively on a three-tier scale. RESULTS: Immunostaining for Bcl-2 protein was intense (2-3+) in 7 LA-treated and 10 untreated leiomyomas but was scarce (0-1+) in normal myometrial smooth muscle. CONCLUSION: Abundant expression of Bcl-2 protein may be responsible for the growth of leiomyomas by preventing apoptotic cell death. Its increased expression is maintained in GnRH-a-treated leiomyomas.