Fibroids: Pathophysiology and current medical treatment

Uterine leiomyomas, or fibroids, are a major cause of abnormal uterine bleeding in women. These benign tumours develop during the reproductive years and their growth has been shown to be dependent on the ovarian steroid hormones oestradiol and progesterone. The growth promoting effects of these steroid hormones appear to be mediated through the local production of specific growth factors. Traditional treatment for leiomyomas has been surgical removal through either hysterectomy or myomectomy. Newer surgical techniques, such as hysteroscopic removal of leiomyomas, endometrial ablation, or uterine arterial embolization, are now being tested as effective but less invasive methods of treatment. Non-surgical treatment of leiomyomas has been primarily through the use of gonadotrophin-releasing hormone agonists which suppress circulating oestradiol and progesterone levels by shutting down the pituitary-ovarian axis. The suppression in steroid hormone levels results in significant fibroid shrinkage, but long-term use of these compounds is not recommended because patients suffer significant bone loss. New antisteroidal compounds, such as the antiprogestin RU 486 and the selective oestrogen-receptor modulator raloxifene, are now being tested as possible therapeutic agents for fibroids.