A possible role of progestins in fibroids growth stimulation

Uterine fibroids is a hormone-dependent tumor. Estrogens are considered traditionally as a main stimulator of fibroids growth. However, there are many investigations which show not only estrogens but also gestagens can stimulates cell proliferation in fibroids. Progesterone modulates a mitotic activity in myometrium and fibroids nodes. Randomized clinical studies with agonists of re-leasing-hormone and hormone-replacement treatment demonstrates an ability of progestin's to stimulate fibroids growth in spite of hypoestrogenic background.