Prediction of the shrinking rate of uterine leiomyoma nodules using needle biopsy specimens.

To determine correlations between shrinkage of uterine leiomyomas after treatment with GnRH agonists (GnRH-a) or menopause and expression levels of estrogen receptors (ER), progesterone receptors (PR), and vascular endothelial growth factor (VEGF). Cohort study. University teaching hospital. A total of 26 women with uterine leiomyoma. Ten women were treated with buserelin acetate injection (1.8 mg), four courses every 4 weeks, and 16 women went into menopause naturally. Tumor shrinkage rates determined from magnetic resonance images taken before and after GnRH-a therapy and before and after natural menopause; immunohistochemical analysis of ER, PR, and VEGF in uterine leiomyoma biopsy specimens taken before intervention or within 6 months before menopause. Shrinkage rates of uterine leiomyomas were positively correlated with expression levels of ER in women treated with GnRH-a and in postmenopausal women managed conservatively, and with VEGF expression in women treated with GnRH-a. There were no significant correlations with PR expression levels in either group. Estrogen plays the predominant role in myoma shrinkage for women with GnRH-a therapy and naturally menopausal women.