Uterine fibroids, also known as leiomyomas or myomas, are the most common
gynecologic tumor in women of reproductive age, affecting approximately 30 to
40 percent of premenopausal females. The prevalence increases with age, with
an estimated 70 to 80 percent of women developing fibroids by age 50.1
While typically classified as benign, uterine fibroids can cause
troublesome symptoms to approximately 30 percent of affected women, including
heavy vaginal bleeding, pelvic pressure, pain, obstructive urinary and bowel
symptoms, as well as reproductive difficulties.1,2 Fibroids are one
of the most common indications for hysterectomy in the U.S., accounting for approximately
200,000 cases per year. Fibroid-related morbidity has a significant economic
impact on health care: the cost of health care for women with fibroids is more
than double that of women without this condition, and annual costs related to
the diagnosis of fibroids are over $2 billion.3
Fortunately, new approaches to managing uterine fibroids are improving the
outlook. Minimally invasive and non-invasive treatments such as MRgFUS (MRI-guided
focused ultrasound) - a novel therapy recently introduced f at Duke - are providing
effective treatment for fibroids while offering faster recovery and fewer complications
than hysterectomy.4 At the same time, new studies have increased our understanding
of the biology of uterine fibroids and created inroads for developing more effective
medical therapies.
What Causes Uterine Fibroids, and Who Is at Risk?
While the exact etiology of fibroids is still unclear, physician-scientists
at the Duke Center for Uterine Fibroid Biology and Therapy have co-authored several
of the most recent studies examining the underlying disease process that leads
to the formation of uterine fibroids.5,6,7 These studies indicate
that fibroids grow by accumulation of collagen and components of the extracellular
matrix. This fibrosis is similar to that observed in the formation of keloid
scars. The Center, which includes physician investigators, basic scientists,
and epidemiologists, is currently involved in several studies to elucidate the
molecular biology of uterine fibroid growth and etiology for associated bleeding
and subfertility.
Factors implicated in the development of fibroids include genetic, hormonal,
and growth factors, especially transforming growth factor beta (TGFb)-related
cellular changes.8,9 Clinical risk factors associated with fibroids include obesity,
hypertension, nulliparity (having no biological children), family history, and
race. Up to 70 percent of African American women have uterine fibroids, and these
generally tend to be larger, more numerous, and produce more severe symptoms.1
How Are Uterine Fibroids Best Diagnosed?
Given the fact that uterine fibroids are highly prevalent in childbearing
women and are associated with decreased fertility, prompt and accurate diagnosis
is important. Uterine fibroids are most often diagnosed by ultrasound as part
of the evaluation for associated symptoms or when an enlarged uterus is found
on physical examination. However, other imaging modalities such as saline infusion
sonograpy (3-D) and MRI may provide more accurate diagnosis and better delineation
of fibroid size and location.
Fibroids are classified based on location within the uterine wall: subserosal,
intramural, and submucosal. These definitions are often used to determine appropriate
interventions and/or surgical approach.
What Are Current Treatment Approaches - And What Therapies Are on the Horizon?
Current treatment options for uterine fibroids run the gamut from medical
intervention to non-invasive and minimally invasive therapies to hysterectomy.
Several factors must be addressed in determining the appropriate treatment for
each individual, including size and location of fibroids, severity of symptoms,
and desire to retain fertility or uterine preservation.
Medical options. Current medical options for fibroid management are limited.
Of the established interventions, GnRh agonists are the most effective. GnRHa
have been used to control bleeding and pressure-related symptoms by reducing
fibroid size and decreasing bleeding. Within three to six months, fibroid size
is reduced by approximately 30 to 50 percent. However, these effects are short-
lived; fibroids grow and symptoms recur soon after treatment is discontinued.
Furthermore, due to hypoestrogenic effects, treatment time is limited to six
months, after which bone density can be affected. Add-back hormone therapy can
be used to combat this effect, but some studies have found that this regimen
may decrease the treatment efficacy. Hence GnRh agonists have been found to be
most useful as an adjunct to surgical treatment of fibroids, since preoperative
use results in improvement in hematocrit levels and less blood loss during surgery.10
Table 1 - Medical therapy for fibroids 10–16
DRUG CLASS |
MECHANISM |
EFFECTS |
CONSIDERATIONS |
GnRH agonists |
Suppression of ovarian steroidogenesis production - delayed pituitary downregulation |
Fibroid size and symptom reduction up to 50% within 3-6 months |
Hypoestrogenic side effects: hot flashes, vaginal dryness, headaches. Prolonged
use associated with reduced bone mineral density |
GnRH antagonists |
Suppression of ovarian steroidogenesis production - immediate pituitary downregulation |
Reduction in fibroid size 25-40% and symptom improvement within 3 weeks |
Hypoestrogenic side effects: hot flashes, vaginal dryness, headaches. Prolonged
use associated with reduced bone mineral density |
Oral contraceptives |
Endometrial stabilization, variable effects on leiomyomas |
May improve uterine bleeding, but no significant decrease in fibroid size |
Use judiciously - both estrogen and progesterone may promote fibroid growth
(increased mitotic activity) |
Progestin only |
Endometrial stabilization/atrophy, variable effects on leiomyomas |
Mixed results - both fibroid shrinkage and enlargement have been shown; may
induce amenorrhea |
Use judiciously - progesterone may promote fibroid growth (increased mitotic
activity) |
Androgens |
Combination hormonal and vascular effects (androgenic, progestogenic, antiprogestogenic,
and antiestrogenic actions) |
24% fibroid size reduction in 4 months, may improve bleeding symptoms
|
Side effects: weight gain, edema, acne, oily skin, hirsutism, voice changes,
headaches, hot flashes, altered libido, decreased breast size, and muscle cramps |
Aromatase inhibitors* |
Reduces estrogen synthesis and effects |
Fibroid size reduced 60-70% within 1-2 months in case report |
Hypoestrogenic side effects; further studies needed |
Antiprogestins* |
Anti-progesterone effect - reduces action and number of progesterone receptors
in fibroids and myometrium |
Improved symptoms in 60-75%, may induce amenorrhea, reduction in fibroid
volume 25-50% within 3 months
|
Side effects include hot flashes, elevated hepatic enzymes, and endometrial
hyperplasia |
Mixed progesterone receptor antagonist/agonists* |
Local progesterone-mediated effects on leiomyomas and endometrium |
Decreased menstrual bleeding (up to 80%) and fibroid size reduction up
to 36% within 12 wks, may induce amenorrhea
|
Maintains follicular phase estrogen levels, no adverse endometrial effects
- causes nonphysiologic secretory changes (clinical relevance unknown) |
Mixed estrogen receptor antagonist/agonists* |
Estrogen antagonist effects on fibroid and endometrium |
Inconsistent results - trend to decreased fibroid size in small heterogeneous
studies |
Side effects: leg cramps, hot flashes. Increased risk of thromboembolic events |
Antifibrotics* |
Interfere with growth factors, leiomyoma cell proliferation and extracellular
matrix/ collagen production |
Interfere with fibroid growth |
Long-term effects not known, further studies needed |
*Investigational medical therapies
Several other hormone-related medical treatments have been used to treat uterine
fibroids; however, most of these medications are still being evaluated in clinical
trials and are considered investigational.11 Some of these proposed interventions
are aimed at controlling fibroid growth and related symptoms by targeting ovarian
steroid production. These include combined birth control pills, progestin-only
preparations, androgens, both estrogen and progesterone receptor antagonists,
and mixed receptor antagonist/agonists. Other medications, such as antifibrotic
agents, target growth factors and affect extracellular matrix production and
angiogenesis within the fibroid. These medical treatments are summarized in Table
1. The Duke Center for Uterine Fibroid Biology and Therapy is actively investigating
new drug therapies to treat uterine fibroids, and we expect this to be an area
of significant advancement and progress over the next several years.
Non-medical options. Since most medical options are investigational and not
recommended as first-line, long-term treatment for symptomatic fibroids at this
time, the most common treatments remain either conservative surgical intervention
or definitive surgery. Until now, the most prevalent treatments have been hysterectomy
(surgical removal of the uterus) and myomectomy (surgical removal of individual
fibroids). However, more women are looking for options that provide minimal intervention
and shorter recovery time.
Minimally invasive surgical treatments can provide excellent results when
patient and fibroid characteristics are appropriate. In general, such treatments
are best suited for women with a few, discrete symptomatic fibroids, while extensive
fibroids are best treated with more definitive approaches. Minimally invasive
approaches include laparoscopic and hysteroscopic myomectomy, as well as uterine
artery embolization, a radiologic procedure that has also become more popular
over the last several years.
Table 2. non-medical treatment interventions - conservative and definitive
4, 17 - 19
| TREATMENT |
MECHANISM |
EFFECTS |
CONSIDERATIONS |
Uterine artery embolization |
Ischemic necrosis |
Fibroid size reduction 40-60% within 4 months, menorrhagia improvement
up to 85% |
Post-procedure pain, risk of major adverse events (such as serious
infectious complications)1-2%, may be associated with adverse pregnancy outcomes,
ovarian failure in 1-2% |
MRI-guided focused ultrasound |
Localized thermal necrosis |
Symptomatic improvement up to 71% within 3 months, fibroid size reduction
up to 30% - increased in proportion to treated fibroid volume, treatment effects
sustained up to 24 months with low rates of secondary or repeat procedures |
Patient selection criteria and fibroid characteristics important - post-treatment
volume determines efficiency/duration of clinical results; minimal risk of adverse
events (skin burn, nerve injury) |
Myolysis (Laparoscopic) |
Thermal necrosis |
Fibroid shrinkage up to 70% by 12 months |
Surgical risks, significant postoperative adhesions |
Laparoscopic myomectomy |
Excision |
Removal of large fibroids, high patient satisfaction with symptomatic improvement |
Surgical risks; often requires cesarean delivery with future pregnancy -
labor is not advised, due to small risk of uterine rupture |
Abdominal myomectomy |
Excision |
Removal of all palpable fibroids, high patient satisfaction with symptomatic
improvement |
Surgical risks; often requires cesarean delivery with future pregnancy -
labor is not advised, due to small risk of uterine rupture |
| Hysterectomy |
Excision |
Definitive treatment - high patient satisfaction rate with symptomatic improvement |
Surgical risks |
A recent addition to the treatment toolkit is MRI-guided focused ultrasound
(MRgFUS), in which precisely pinpointed, high-intensity ultrasound waves are
used to “burn away” fibroids without harming normal surrounding
tissues. This cutting-edge technology, which offers women the option of same-day,
non-surgical treatment, is available at Duke through the Duke MRI-Guided Focused
Ultrasound Treatment Program. With increasing availability of conservative treatment
choices, both patients and their physicians
have the opportunity to individualize therapy
based on the goals of each patient. More
details on the pros and cons of various nonmedical
therapies are in Table 2.
Phyllis C. Leppert, MD, PhD, is a professor and
vice chair for research in the Duke Department
of Obstetrics and Gynecology, and also
director of the new Duke Center for Uterine
Fibroid Biology and Therapy. Millie Behera, MD,
is an assistant professor in the Department of
Obstetrics and Gynecology, clinical director
of the Duke Center for Uterine Fibroid Biology
and Therapy, and director of the Duke MRI
Guided Focused Ultrasound Treatment Program.
1 Day Baird D, Dunson DB, Hill MC, Cousins D, Schectman JM. High cumulative
incidence of uterine leiomyoma in black and white women: ultrasound evidence.
Am J Obstet Gynecol. 2003 Jan;188(1):100 - 7
2 Buttram VC Jr, Reiter RC. Uterine leiomyomata: etiology, symptomatology,
and management. Fertil Steril. 1981 Oct;36(4):433 - 35
3 Hartmann KE, Birnbaum H, Ben-Hamadi R, Wu EQ, Farrell MH, Spalding J, Stang
P. Annual costs associated with diagnosis of uterine leiomyomata. Obstet Gynecol.
2006 Oct;108(4):930 - 7
4 Stewart EA, Gostout B, Rabinovici J, Kim HS, Regan L, Tempany CM. Sustained
relief of leiomyoma symptoms by using focused ultrasound surgery. Obstet Gynecol.
2007 Aug;110(2 Pt 1):279 - 87
5 Behera M, Feng L, Yonish B, Catherino W, Leppert PC. Thrombospondin-1 (TSP-1 and Thrombospondin-2 (TSP-2) mRNA and protein expression in uterine fibroids
and correlation to COL1A1 and hydroxyproline. Reprod Sci. 2007 Dec;14(8S):63
- 76
6 Catherino WH, Leppert PC, Stenmark MH, Payson M, Potlog-Nahari C, Nieman
LK, Segars J. Reduced dermatopontin expression is a molecular link between uterine
leiomyomas and keloids. Genes Chromosomes Cancer. 2004 Jul;40(3):204 - 17
7Leppert PC, Baginski T, Prupas C, Catherino WH, Pletcher S, Segars J. Comparative
ultrastructure of collagen fibrils in uterine leiomyomas and normal myometrium.
Fertil Steril. 2004 Oct;82 Suppl 3:1182 - 7
8Parker WH. Etiology, symptomatology, and diagnosis of uterine myomas. Fertil
Steril. 2007 Apr;87(4):725 - 36
9 Walker CL. Uterine fibroids: the elephant in the room. Science. 2005 Jun
10;308(5728):1589 - 92
10Lethaby A, Vollenhoven B, Sowter M. Efficacy of pre-operative
gonadotrophin hormone releasing analogues for women with uterine fibroids undergoing
hysterectomy or myomectomy: a systematic review. BJOG. 2002 Oct;109(10):1097
- 1108
11 Rackow BW, Arici A. Options for medical treatment of myomas. Obstet Gynecol
Clin North Am. 2006 Mar;33(1):97 - 113
12 Lingxia X, Taixiang W, Xiaoyan C. Selective estrogen receptor modulators
(SERMs) for uterine leiomyomas (Review). Cochrane Database Syst Rev. 2007 Apr
18;(2):CD005287.
13 Chwalisz K, Larsen L, Mattia-Goldberg C, Edmonds A, Elger W, Winkel CA.
A randomized, controlled trial of asoprisnil, a novel selective progesterone
receptor modulator, in women with uterine leiomyomata. Fertil Steril 2007 Jun;87(6):1399 - 412.
Epub 2007 Feb 20
14 Maruo T, Ohara N, Wang J, Matsuo H. Sex steroidal regulation of uterine
leiomyoma growth and apoptosis. Hum Reprod Update. 2004 May - Jun;10(3):207 - 20
15 Shozu M, Murakami K, Inoue M. Aromatase and leiomyoma of the uterus. Semin
Reprod Med. 2004 Feb;22(1):55 - 60
16 Shozu M, Murakami K, Segawa T, Kasai T, Inoue M. Successful treatment of
a symptomatic uterine leiomyoma in a perimenopausal woman with a nonsteroidal
aromatase inhibitor. Fertil Steril. 2003 Mar;79(3):628 - 31
17 The REST Investigators.
Uterine-artery embolization versus surgery for symptomatic uterine fibroids.
N Engl J Med. 2007 Jan25;356(4):360 - 70
18 Marshburn PB, Matthews ML, Hurst BS. Uterine artery embolization as a treatment
option for uterine myomas. Obstet Gynecol Clin North Am. 2006 Mar;33(1):125 - 44
19 Sharp HT. Assessment of new technology in the treatment of idiopathic menorrhagia
and uterine leiomyomata. Obstet Gynecol. 2006 Oct;108(4):990 - 1003
©Millie Behera M.D. and Phyllis Leppert,
MD, PhD
Duke Department of Obstetrics and Gynecology
http://www.dukehealth.org
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