Uterine fibroids are tumours arising from smooth muscle tissues within the uterus. Another medical term for fibroids is leiomyoma or "myoma". Fibroids are the most common pelvic tumours in women and they are entirely benign.
Fibroids are very common and may affect as many as 25% of all women before the age of 50 years. Some women have a single fibroid mass and others have many fibroids. Fibroids can be small and not bother a patient but some fibroids can grow so large that they occupy the entire abdominal cavity in a woman’s pelvis.
Most fibroids do not cause any symptoms, but some women with fibroids can have:
- Heavy bleeding or painful periods. This can lead to anemia.
- Erratic periods (bleeding in between periods).
- Feeling of fullness or pain in the pelvic area.
- Enlargement of the lower abdomen. This can happen when fibroids are large and women may need to frequently urinate due to pressure on the bladder. The pressure can also cause constipation.
- Pain during intercourse
- Lower back pain
- Infertility or miscarriages.
For some women these symptoms can be mild, while for others they can be debilitating and greatly affect a woman’s quality of life.
If fibroids grow to a massive size, they can cause very serious bleeding, bowel obstruction or obstruction of the urinary collecting system so that women cannot empty the bladder. Cases like those constitute medical emergencies but are rare.
What causes Fibroids?
We don’t know for sure, but factors that can increase a women’s risk include hormones (estrogen and progesterone levels), early menarche, obesity, never having given birth, and family history.
Can fibroids be cancerous?
A women’s chances of developing a cancerous growth within the uterus do not increase because of uterine fibroids, neither does having them increase chances of getting other gynaecological cancers.
Sarcomas and carcinosarcomas are uncommon but highly aggressive malignant tumours (cancer) also arising from smooth muscle tissue of the uterus. We don’t believe that fibroids can turn into sarcomas.
However, sometimes it can be difficult to distinguish between fibroids (benign tumours) and sarcomas (malignant tumours).
How are fibroids diagnosed?
A doctor may be able to feel the lump or mass during a pelvic exam to determine the size and mobility. If a doctor suspects fibroids an ultrasound is the first step to determine what is causing the pelvic symptoms. Very large fibroids should be investigated by MRI scan. Women will be required to have an MRI scan prior to surgical treatment. An MRI will also help determine if there are other conditions present such as adenomyosis.
A definitive diagnosis requires tissue which can be obtained through a Pipelle, myomectomy (to remove the fibroids and preserve the uterus) or a hysterectomy (removal of uterus). A hysterectomy is the most common surgical procedure to treat fibroids.
In premenopausal women in whom ultrasound has shown the typical features of fibroids, a tissue diagnosis does not need to be obtained, if there is no abnormal bleeding pattern.
“Wait and see”
For women who have small fibroids without symptoms, they can usually be followed without any treatment. In many cases, fibroids will shrink over time. Fibroids normally stop growing or shrink once a woman reaches menopause.
Wait and see may not be the ideal option for women with very large fibroids or fibroids that cause symptoms and a definitive diagnosis is recommended.
There is a general lack of good quality data on the medical treatment of fibroids. It is generally accepted that medical treatment provides initial symptom relief in a large number of women, but treatment fails after a year and recurrence of symptoms are very common. A US study suggested that 6 of 10 women who were randomly assigned to oral medical therapy required surgery to treat the fibroids by two years.
- Oral contraceptive pill: Experts are divided whether oestrogen-progesterone combination oral contraceptive pills are effective in the treatment of fibroids. It can be useful with women who experience heavy menstrual bleeding.
- Levonorgestrel-releasing IUD: There are no good quality studies available for the treatment of fibroids with an IUD. However, some gynaecologists believe that it provides good symptomatic relief particularly for women with heavy menstrual bleeding. Fibroids that grow into the uterine cavity should not be treated with an IUD.
- Systemic Progestins: This is widely given to women with fibroids for symptom control to stop bleeding. Whether progestins are effective on the fibroids or have a beneficial effect on the endometrium is unknown. I recommend progestins in case of mild symptoms short-term. Long-term progestin use can lead to diabetes, weight gain and thromboembolic complications.
- Tranexamic acid: Approved for symptomatic treatment of heavy menstrual bleeding. I recommend it to women in combination with progestins to stop very heavy bleeding for a short time.
Medications I do not recommend:
- GnRH agonists, antagonists: This is not recommended to treat fibroids. They require frequent injections and render patients menopausal, causing enormous risks and possible complications. Rapid regrowth of fibroids can occur once injections are stopped.
- Antiprogestins: While progesterone can stimulate growth of fibroids, their antagonists may cause endometrial hyperplasia and even cancer as a complication.
- Mifepristone (RU-486) has been shown to reduce uterine volume by 26% to 74%, provides symptomatic relief and improved quality of life. It is not approved in Australia for the treatment of uterine fibroids (due to political concerns).
Hysterectomy is the definitive procedure with no chance of recurrence of bleeding or pain beyond the postoperative recovery. I recommend hysterectomy for the following women:
- Post- or perimenopausal women with significant and long-standing symptoms.
- Women who failed previous conservative treatments described above.
- Women with fibroids and additional conditions that would be eliminated by hysterectomy (e.g., adenomyosis, history of breast cancer, increased risk of uterine or ovarian cancer).
Hysterectomy should be done vaginally or laparoscopically (key hole or minimally invasive surgery); if the opening of the abdomen is recommended, I recommend that patients look for a second opinion.
Myomectomy is a surgical option for women who have subserosal and intramural fibroids and who desire fertility. Myomectomy is possible because there is often a distinct tissue plane between the fibroid and the surrounding uterus. At myomectomy the uterus is opened and the fibroid(s) are removed one by one. In premenopausal women the surgical approach (open vs. laparoscopic) needs to be discussed. There is a risk of uterine rupture during pregnancy following laparoscopic myomectomy. Because of the surgical risks plus the risk of an underlying cancer I do not recommend a myomectomy to postmenopausal women.
Endometrial ablation is a good option for treatment of bleeding irregularities but not a preferred choice for women with fibroids.
- Uterine artery embolization is an option for women who wish to preserve the uterus but are not interested in pursuing fertility. It is a minimally invasive procedure but associated with a much higher risk of treatment complications and readmissions to hospital than hysterectomy.
- Magnetic resonance guided focused ultrasound is an emerging and novel procedure with very limited data to date. It cannot treat large fibroids. It was only introduced to Australia in 2009. Future studies will be required before the technique can be recommended as an alternative treatment for fibroids.
What I recommend
- Women who have no or only mild symptoms: Wait and see, yearly scans with the GP or IUD.
- Young women who wish to fall pregnant: myomectomy
- Women with significant symptoms or symptoms that recurred after conservative treatment and who do not wish to maintain fertility: hysterectomy