Uterine fibroid tumors are noncancerous growths in the uterus. Frequently found in women between the ages 30-45, fibroids are the most common type of abnormal pelvic growth in women. They account for about one quarter of all hysterectomies performed in the United States each year.
Types and Symptoms
Fibroids develop from cells in the wall of the uterus. Tumors that grow within the uterine wall rarely produce symptoms if they are small.
Fibroids can also grow beneath the uterine lining. As they expand, they can stretch the endometrium, causing heavy menstrual bleeding and severe pain as the uterus tries to expel the mass. Even small fibroids in this location may cause these symptoms.
Some fibroids grow beneath the outside covering of the uterus, or appear to be attached by a stemlike structure to the uterus. All these tumors can grow much larger than the uterus itself.
Large uterine fibroids can cause pain, constipation, frequency of urination and increased menstrual pain and irregularity.
These tumors also can obstruct the fallopian tubes or block implantation of the fertilized egg. If conception does take place, the tumors can cause a miscarriage or premature labor. Rarely, a tumor can block the vagina, forcing a caesarean section.
The cause of uterine fibroids is unknown, but evidence suggests that their growth is tied to estrogen.
When a woman is pregnant or takes certain birth control pills, both of which increase estrogen levels, the normally slow growth rate of the fibroid often accelerates.
Fibroid tumors that cause no symptoms can be left untreated as long as they are monitored closely. However, large uterine fibroids usually require treatment.
Submucus leiomyomas bulging into the uterine cavity can be removed with a simple outpatient procedure where a telescope is placed into the uterine cavity and the tumor is cut out.
To preserve fertility, physicians often elect to perform a myomectomy, or surgical removal of the tumors only, which leaves the uterus in place. A woman who becomes pregnant after a myomectomy may require a caesarean delivery to prevent rupture of the uterus at the myomectomy site.
Hysterectomy, the only real "cure" for fibroids, is the surgical removal of the entire uterus. Hysterectomies are recommended for women with very severe fibroids, and for those who do not intend to become pregnant.
GnRH Agonist Therapy
Because growth of uterine fibroids is tied to estrogen production, the tumors often stop growing or even shrink after menopause. To create a similar effect in women without rendering them sterile, some physicians have been successfully using GnRH agonists; synthetic forms (analogs) of the naturally occurring gonadotropin releasing hormone (GnRH).
||GnRH agonists prescribed before surgery offer these advantages: reduces blood loss during surgery, and may eliminate the need for blood transfusions.
Mechanism of Action
Natural GnRH acts on the pituitary gland in the brain. It stimulates the secretion and release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). These hormones then trigger the ovary to secrete estrogen and progesterone. Ovarian hormones must be produced for ovulation to take place and for uterine fibroids to grow.
However, with continued administration of a GnRH agonist, production of these hormones decreases to menopausal or castrate levels. LupronÒ (leuprolide acetate) Injection and Lupron Depot (leuprolide acetate for depot suspension), manufactured by TAP Pharmaceuticals, are being prescribed by many physicians. As a result, uterine fibroids shrink, providing relief of the symptoms. Maximum shrinakage occurs after three months of treatment.
Leuprolide acetate may be used alone or in conjunction with surgery, depending on the patient and the extent of her fibroids. For the perimenopausal woman, a menopause induced by a GnRH agonist may provide the bridge to the natural state. For the woman of childbearing age, GnRH agonists can often shrink fibroid tumors enough to eliminate the need for a hysterectomy, thereby preserving fertility, when the fibroids alone are removed. Alternatively, their use may allow a simpler laparoscopic hysterectomy, thereby avoiding abdominal surgery.
Although Lupron can be administered daily as a subcutaneous injection, more commonly patients receive a once-a-month injection of Lurpon Depot.
GnRH agonists’side effects are common to menopause. These effects may include hot flashes, mood swings, headaches and vaginal dryness, and are reversible upon cessation of treatment. Patients may experience bone loss during prolonged medically induced menopause. Studies have shown bone loss to be reversible after treatment stops, and may be prevented by use of calcium supplements.
Allergic reactions may occur in some women. Although generally appearing as a localized reaction at the injection site, any type of welt, itching, or redness should be reported to the doctor.
Animal studies show no evidence of cancer.
Women should use barrier contraception during the entire course of GnRH agonist therapy. Lupron is not indicated for women who are pregnant or are trying to become pregnant while using the drug.
Why Should I Consider This Therapy?
GnRH agonists offer a way of altering reproductive hormones to treat conditions that are hormone dependent. Therefore they lessen many of the symptoms of uterine fibroids. A growing body of scientific evidence is showing that Lupron can safely and effectively treat a number of women's reproductive disorders.