Maruo T, Ohara N, Matsuo H et al.
Kobe University Graduate School of Medicine, Kobe, Japan.
Contraception 2007;75:S99–103.
Editor’s note: Uterine leiomyomas are common, occuring in as many as 30% of women over 35 years of age, and their growth is generally thought to be under the control of estrogen. The levonorgestrel-releasing intrauterine system IUS (LNg-IUS) has been shown to be beneficial in controlling menorrhagia in women with leiomyomas both by subjective assessment and by objective assessment of hemoglobin levels. The endometrial mechanism involved in the control of tumor growth is a combination of inhibition of proliferation and an increase in the levels of apoptosis. However, the mitogenic role of progesterone on leiomyoma remains unclear. The authors were therefore prompted to examine the effects of progesterone and the progesterone receptor modulator CDB2914 on these tumors. CDB2914 binds competitively to the progesterone receptor with high affinity and has few antiglucocorticoid effects.