Effects of Mifepristone on the expression of EGF in human uterine leiomyoma

Objective:To study the effects of Mifepristone on the expression of epidermal growth factor(EGF),estrogen receptor(ER) ,progesterone receptor(PR) and on sexual hormones in human uterine leiomyoma and myometrium.Methods:11 patients with uterine leiomyoma who had surgical indication received 12.5 mg of Mifepristone daily for 90 days beginning on the second to the third day of menstrual cycle.Complete blood count,serum sexual hormonal parameters,serum cortisol,liver function,ultrasound examination were monitored prior to and at the end of treatment.Hysterectomy or myomectomy was performed when the treatment finished.Leiomyomata and myometrial tissue were obtained for immunohistochemical EGF,ER and PR analyses using monoclonal antibody.Control group included 11 patients who had matched age,weight,size and position of leiomyoma,and operate in the follicular phase of the cycle.Results:After 90 days of Mifepristone treatment,the leiomyoma volume decreased 28.62% and the uterine volume decreased 51.43%.Hemoglobin was increased(P=0.017).Hormonal parameters were within the levels of follicular phase.In leiomyoma ER,PR,EGF positive rate of control group(P=0.003,P=0.000,P=0.001) and PR of study group(P=0.040) were higher than those in myometrium.In leiomyoma ER,PR,EGF positive rate of study group were significantly less than those of control group in myometrium(P=0.031,P=0.040,P=0.021).In myometrium PR,EGF positive rate of study group were less than those of control group(P=0.041,P=0.003).Conclusion:In leiomyoma EGF,ER,PR positive rate are higher than those in myometrium.Mifepristone can inhibited leiomyoma growth by inhibiting sexual hormone,resulting in a lower EGF,ER,PR expression in leiomyoma cells and a lower EGF,PR expression in myometrium cell and inhibiting the effect of augmenting EGF by progesterone.Mifepristone is a safe and effective drug for treating uterine leiomyoma.