Uterine fibroids

“I gave birth to a 6-lb, 7-oz fibroid!”

Stephanie, a single, African-American woman, discovered in her late 20s that she had several small fibroids and a large one growing within the walls of her uterus. The fibroids caused excessive bleeding and pain so intense that her gynecologist suggested surgery to remove them. Incredibly, 50–75% of women have or will suffer uterine fibroids, and roughly 30% of those women are of reproductive age. Many are not even aware that they have fibroids, because fewer than half of the cases cause symptoms. This is indeed astonishing.

Fibroids are tumors that are composed of smooth muscle cells and fibrous connective tissue that grow within the walls of the uterus. These tumors, also referred to as uterine myomas or leiomyomas, are typically benign and are most common in women who are of pre- or current menopausal age (30–50 years old). Fibroids are often confused with cysts. Fibroids are solid tissue; a cyst is a fluid-filled sac.

Fibroids may be as small as a pea or as large as 8 in. in diameter. Estrogen, a steroid hormone produced by the ovaries, causes uterine fibroids to flourish in the body. A woman with large fibroids will have an oversized uterus, causing her to look as though she is about four months pregnant. Surprisingly, the exact cause of fibroids is not known, but certain groups of women are more likely than others to develop them.

Risk factors
No specific risk factors that promote the formation of fibroids have been identified; however, researchers have discovered that the women most likely to develop fibroids are those who

• have never been pregnant,
• have a family history of fibroids, or
• are African-American.

Stephanie’s history puts her into a group that is likely to develop fibroids. Her condition was no surprise to her mother and two aunts, who all had suffered from fibroids and required surgery.

Symptoms
Because most women with fibroids are not aware that they have them, treatment is usually not needed unless they are linked with pain or unexplained bleeding. Depending on the size, location, and number of tumors, fibroids may be associated with the following symptoms:

• anemia,
• bleeding between periods,
• constipation,
• feeling of fullness in the lower part of the abdomen,
• heavy menstrual bleeding,
• lower back pain,
• miscarriage,
• pain during periods and/or sexual intercourse, and
• repeated urinary tract infections.

Most often, doctors recommend watching and waiting if the fibroids are small and not causing any problems. Because fibroids grow in response to estrogen, they usually stabilize or shrink after menopause, when estrogen levels fall. Therefore, more often than not, waiting for menopause will solve the problem. However, if the fibroids are coupled with excessive bleeding during or between periods, anemia may be forthcoming. Fibroids are also known to press on the bladder, causing frequent urination or incontinence. Additionally, fibroids may interfere with fertility by blocking the fallopian tubes or preventing the placenta from implanting properly in the uterus.

Diagnosis
Fibroids are usually identified through a pelvic exam but can easily be missed, or the symptoms may be mistakenly ascribed to other conditions such as adenomyosis or ovarian cysts. For this reason, if a woman is experiencing symptoms such as abnormal bleeding or cramping, an ultrasound examination is commonly performed to confirm the presence, size, and location of the tumors. Vaginal probe ultrasound only takes a few minutes, is not uncomfortable, and quickly provides very useful information, especially when the examiner is experienced in detecting uterine abnormalities. In some cases, the physician may look directly inside the uterus with a small scope or may request that a magnetic resonance imaging (MRI) procedure be performed. Regardless of the method chosen, once a positive diagnosis of fibroids has been made, several treatment options are available through consultation with a doctor.

Treatment
The choices for treatment of uterine fibroids are seemingly endless, but the common goal of all treatment is to reduce estrogen levels in the woman’s body, because the tumors depend on estrogen for growth. The most extreme treatment option of fibroids is a hysterectomy—a surgical procedure that completely removes the uterus. According to the National Center for Health Statistics, fibroids are the cause of one-third to one-half of the 600,000 hysterectomies performed in the United States annually. Although a hysterectomy eliminates fibroids, symptoms, and the chance for recurrence, it also prevents any possibility of pregnancy.

A procedure that is similar to the hysterectomy but avoids removal of the uterus is the myomectomy, an abdominal incision and surgical removal of the fibroids. The drawback to a myomectomy is that the risk of fibroid recurrence is high. About 50% of patients require repeat surgery within five years.

Figure 1. Fibroids and embolization. Myomas can take root in a variety of locations throughout the uterine walls and cavities. A myoma’s blood supply, however, can be cut off by the release of small plastic seeds into a uterine artery to block the flow of blood through the capillaries that feed the fibroid.

A third technique, uterine fibroid embolization, is a somewhat newer alternative to hysterectomy or myomectomy (Figure 1). This procedure “starves” fibroids, causing them to shrink. The technique involves snaking a tiny catheter through the femoral artery in the patient’s groin to the arteries that supply the fibroids with blood. The catheter delivers tiny plastic pellets that lodge in the blood vessels and cut off the blood and nutrient supply to the fibroid.

In a study conducted by the Stanford University Medical Center, 90% of 73 embolization patients experienced a reduction in their once-heavy menstrual bleeding. This outpatient procedure has been reported to decrease bleeding and pain from the fibroids immediately. This procedure also preserves fertility, because the ovaries and uterus are kept intact. It has been argued, however, that embolization can lead to early ovarian failure, because a small number of women have reported that their menstrual cycle completely stopped after the procedure. In addition, pain is commonly reported in connection with this method. Because this is a relatively new procedure, it cannot be said for certain whether patients will suffer a recurrence of fibroids.

Nickel–titanium needles are used in yet another treatment of fibroids—laser ablation. This system burns the core from a fibroid, causing it to die. A team of researchers from St. Mary’s Hospital in London successfully performed this surgical technique on 52 women. Four needles are inserted in the anterior abdomen and guided to the fibroid by an MRI. Three months after the procedure, the fibroids reportedly shrunk by an average of 35–50%. This treatment does not eliminate the fibroids, but it reduces them, thereby removing severe symptoms.

Medication
Various drugs are available to treat fibroids.This form of treatment is ever expanding and may ultimately represent a major treatment option.

Gonadotropin-releasing hormone is a compound prescribed to shrink fibroid tumors. This treatment works by reducing hormone production in the body, thus limiting fibroid growth. Danazol is an androgenic steroid most commonly used for the medical treatment of endometriosis, but it can also be useful by inducing amenorrhea—abnormal suppression or absence of menstruation—to control myoma-related anemia caused by heavy menstrual flow.

Another androgenic steroid, gestrinone, has also been tested. It causes volume reduction and amenorrhoea in women with myomas.

Hormones that reduce symptoms from fibroids include birth-control pills, progestins such as Megace, and the experimental drug RU-486, the “morning after” pill. In addition, nonsteroidal anti-inflammatory drugs such as the over-the-counter medication Motrin can also be helpful in controlling many of the symptoms caused by fibroids.

Preventive measures
Unfortunately, because the cause of the tumors is not entirely known, there is no way to prevent the onset of uterine fibroids. If a woman falls into any one of the categories that make her most at risk, she should be checked for fibroids at each visit to her doctor.

Stephanie, the 20-something African-American sufferer of uterine fibroids, opted for a myomectomy as her choice of treatment. “I want children someday, [so] a hysterectomy is out of the question,” Stephanie says with a hopeful grin. “It’s been two years since my operation. So far, no recurrence!”

Further reading

• Cutler, W. B. Hysterectomy: Before and After: A Comprehensive Guide to Preventing, Preparing for, and Maximizing Health after Hysterectomy; HarperCollins: New York, 1990.
• Stewart, E. A. Uterine Fibroids. Lancet 2001, 357, 293–298.