Effects of treatment with gonadotropin releasing hormone agonist on the uterine leiomyomata structure

Current and Emerging Treatment Options for Uterine Fibroids

Uterine fibroids are the most common benign neoplasm of the female reproductive tract in reproductive age women. Their prevalence is age dependent and can be detected in up to 80% of women by the age of 50 years. Patients affected by uterine fibroids may experience a significant physical, emotional, social, and financial toll as well as losses in their quality of life. Unfortunately, curative hysterectomy abolishes future pregnancy potential, while uterine-sparing surgical and radiologic alternatives are variously associated with reduced long-term reproductive function and/or high tumor recurrence rates. Recently, pharmacological treatment against uterine fibroids have been widely considered by patients to limit uterine fibroid-associated symptoms such as heavy menstrual bleeding. This hormonal therapy seemed effective through blocking the stimulatory effects of gonadal steroid hormones on uterine fibroid growth. However, they are contraindicated in women actively pursuing pregnancy and otherwise effective only during use, which is limited because of long-term safety and other concerns. Accordingly, there is an urgent unmet need for safe, durable, and fertility-compatible non-surgical treatment options for uterine fibroids. In this review article, we cover the current pharmacological treatments for uterine fibroids including their comparable efficacy and side effects as well as emerging safe natural compounds with promising anti-uterine fibroid effects.

Update on the Role and Regulatory Mechanism of Extracellular Matrix in the Pathogenesis of Uterine Fibroids

Uterine fibroids (UFs), also known as leiomyomas, are benign tumors of the myometrium affecting over 70% of women worldwide, particularly women of color. Although benign, UFs are associated with significant morbidity; they are the primary indication for hysterectomy and a major source of gynecologic and reproductive dysfunction, ranging from menorrhagia and pelvic pain to infertility, recurrent miscarriage, and preterm labor. So far, the molecular mechanisms underlying the pathogenesis of UFs are still quite limited. A knowledge gap needs to be filled to help develop novel strategies that will ultimately facilitate the development of therapies and improve UF patient outcomes. Excessive ECM accumulation and aberrant remodeling are crucial for fibrotic diseases and excessive ECM deposition is the central characteristics of UFs. This review summarizes the recent progress of ascertaining the biological functions and regulatory mechanisms in UFs, from the perspective of factors regulating ECM production, ECM-mediated signaling, and pharmacological drugs targeting ECM accumulation. In addition, we provide the current state of knowledge by discussing the molecular mechanisms underlying the regulation and emerging role of the extracellular matrix in the pathogenesis of UFs and in applications. Comprehensive and deeper insights into ECM-mediated alterations and interactions in cellular events will help develop novel strategies to treat patients with this common tumor.

Uterine fibroids: current perspectives

Uterine fibroids are a major cause of morbidity in women of a reproductive age (and sometimes even after menopause). There are several factors that are attributed to underlie the development and incidence of these common tumors, but this further corroborates their relatively unknown etiology. The most likely presentation of fibroids is by their effect on the woman's menstrual cycle or pelvic pressure symptoms. Leiomyosarcoma is a very rare entity that should be suspected in postmenopausal women with fibroid growth (and no concurrent hormone replacement therapy). The gold standard diagnostic modality for uterine fibroids appears to be gray-scale ultrasonography, with magnetic resonance imaging being a close second option in complex clinical circumstances. The management of uterine fibroids can be approached medically, surgically, and even by minimal access techniques. The recent introduction of selective progesterone receptor modulators (SPRMs) and aromatase inhibitors has added more armamentarium to the medical options of treatment. Uterine artery embolization (UAE) has now been well-recognized as a uterine-sparing (fertility-preserving) method of treating fibroids. More recently, the introduction of ultrasound waves (MRgFUS) or radiofrequency (VizAblate™ and Acessa™) for uterine fibroid ablation has added to the options of minimal access treatment. More definite surgery in the form of myomectomy or hysterectomy can be performed via the minimal access or open route methods. Our article seeks to review the already established information on uterine fibroids with added emphasis on contemporary knowledge.

Does three-dimensional power Doppler ultrasound predict histopathological findings of uterine fibroids? A preliminary study

OBJECTIVES

To compare three-dimensional (3D) power Doppler sonographic characteristics of fibroids with histopathological parameters.

METHODS

We evaluated sonographically 73 fibroids before myomectomy or hysterectomy. For each, the total fibroid volume, a shell of 3 mm and a 1-cm(3) spherical sample from the most vascularized area on subjective assessment were captured. 3D power Doppler vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were generated in the acquired volumes. The degree of cellularity, ischemic necrosis and fibrosclerosis, as well as CD31 and Ki-67 staining for vascular density and proliferation index, respectively, were estimated using the surgical sample. Pathological data were considered as dependent variables and ultrasound data as independent variables in multivariable logistic regression models including patients' characteristics.

RESULTS

A high histological 'cellular activity score', combining hypercellularity, a fibrosclerosis rate < 25% and positive Ki-67 staining, was statistically related in multivariate analyses to high 3D power Doppler VI in spherical samples (odds ratio (OR), 1.1 (95% CI, 1.0-1.3), P < 0.05) and VFI (OR, 1.3 (95% CI, 1.0-1.8), P < 0.05). Positive CD31 staining was statistically related to high 3D power Doppler VI in spherical samples (OR, 1.1 (95% CI, 1.0-1.3), P < 0.05). In contrast, ischemic necrosis was statistically related to low 3D power Doppler VI in the total volume (OR, 0.6 (95% CI, 0.4-1.0), P < 0.05) and VFI (OR, 0.4 (95% CI, 0.1-1.1), P < 0.05).

CONCLUSION

Vascular density, ischemic necrosis and histological cellular activity score are statistically significantly associated with some 3D power Doppler indices.

A randomized, controlled clinical trial comparing the effects of aromatase inhibitor (letrozole) and gonadotropin-releasing hormone agonist (triptorelin) on uterine leiomyoma volume and hormonal status

OBJECTIVE

To examine and compare the efficacy and safety of GnRH agonist (GnRHa) vs. aromatase inhibitor in premenopausal women with leiomyomas.

DESIGN

Multicenter, randomized, controlled clinical trial.

SETTING

University hospitals.

PATIENT(S)

A total of 70 subjects with a single uterine myoma measuring >or=5 cm. Subjects were randomized into two groups with use of a random table. They were treated with aromatase inhibitor (group A) or GnRHa (group B).

INTERVENTION(S)

Group A received letrozole (2.5 mg/d) for 12 weeks. Group B received triptorelin (3.75 mg/mo) for 12 weeks.

MAIN OUTCOME MEASURE(S)

Measurement of myoma volume and E(2), FSH, LH, and T levels.

RESULT(S)

Total myoma volume decreased by 45.6% in group A and 33.2% in group B. Reductions in myoma volume in the two groups were statistically significant. There was no significant change in hormonal milieu in group A. The serum level of hormones significantly decreased in group B by the 12th week of treatment.

CONCLUSION(S)

Uterine myoma volume was successfully reduced by use of an aromatase inhibitor. Rapid onset of action and avoidance of initial gonadotropin flare with an aromatase inhibitor may be advantageous for short-term management of women with myomas of any size who are to be managed transiently and who wish to avoid surgical intervention, specifically women with unexplained infertility having uterine myoma.

Uterine leiomyoma with massive lymphoid infiltrate after colon cancer chemotherapy: an immunohistochemical investigation with special reference to lysosome-associated membrane protein expression

Uterine leiomyoma with massive lymphoid infiltration is a rare morphologic phenomenon. We describe the first case of uterine leiomyoma with lymphoid infiltration observed in a patient after chemotherapy for sigmoid cancer. We performed immunohistochemical analysis with a panel of antibodies to several markers. Detection of CD20, CD3, Ki67, CD68 and Epstein-Barr virus nuclear antigen assisted in the differential diagnosis and partial elucidation of the pathogenesis. In addition, we examined the lysosome-associated membrane proteins LAMP-1 and LAMP-2 for the first time in this lesion. Their expression was elevated, indicating enhanced autophagy, an indirect sign of degenerative changes in this benign tumor characterized by massive lymphoid infiltration.

Medical management of fibroids

The ideal medical therapy for fibroids is, arguably, a tablet that is taken by mouth, once a day or, even better, once a week, with minimal, if any, side-effects, that induces fibroid regression and thus a resolution of symptoms rapidly, but without affecting fertility. Such a magic bullet does not yet exist, and there are no indications that one is on the horizon. Driven by the observation that fibroid growth is hormone dependent, current medical treatments mainly involve hormonal manipulations. Gonadotrophin-releasing hormone analogues (GnRHa) have been the most widely used, and while they do cause fibroid regression, they can only be used in the short term, as temporizing measures in the perimenopausal woman, or pre-operatively to reduce fibroid size, influence the type of surgery, restore haemoglobin levels and apparently reduce blood loss at operation. They are notorious for rebound growth of the fibroids upon cessation of therapy, and have major side-effects. GnRH antagonists avoid the initial flare effect seen with GnRHa therapy, but otherwise do not appear to have any additional advantages over GnRHa. Selective oestrogen receptor modulators, such as raloxifene, have been shown to induce fibroid regression effectively in post-, but not pre-, menopausal women; even in the former group, experience with these drugs is limited, and they are associated with significant side-effects. Aromatase inhibitors only appear to be effective in postmenopausal women, have potentially significant long-term side-effects, and experience with their use is also limited. There are suggestions that the levonorgestrel intra-uterine system can cause dramatic reduction in menstrual flow in women with fibroids, but to date there have been no RCTs of its use in these women, in whom rates of expulsion of the device appear to be high. The progesterone antagonists mifepristone and asoprisnil have shown significant promise and warrant further research, as they appear to show efficacy in inducing fibroid regression without major side-effects. However, they and the other hormonal therapies that alter oestrogen and progesterone production or function significantly (danazol, gestrinone) are not compatible with reproduction. Therefore, the quest for the ideal medical therapy for fibroid disease continues, and increasing understanding of fibroid biology is ushering in non-hormonal therapies, although all are confined to laboratory experimentation at present. In the meantime, surgical and radiological approaches remain the mainstay effective therapies.

A comparative study of the effect of raloxifene and gosereline on uterine leiomyoma volume changes and estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically in premenopausal women

OBJECTIVE

To compare the mechanism of action of raloxifene and gosereline induced shrinkage of leiomyomas via estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically.

STUDY DESIGN

Thirty-two premenopausal women affected by uterine leiomyomas were randomized into two equal groups. Group A was treated with gosereline (3.6 mg subcutaneous injection monthly) and group B was treated with raloxifene (60 mg daily per os) for 3 months before undergoing surgery. At entry and at the end of the treatment the leiomyoma volume was measured ultrasonografically and the volume change was calculated. Immunohistochemical detection of estrogen receptor (ER), progesterone receptor (PR), bcl-2 and p53 were performed on leiomyoma tissue samples from group A, group B and the matched-control group. H-scores for ER, PR, bcl-2 and p53 were calculated. The mean volume changes of leiomyomas and immunohistochemical H-score differences of ER, PR, bcl-2 and p53 were compared between groups.

RESULTS

The leiomyoma volume decreased significantly after treatment in gosereline group from baseline of 65 cm(3) to 35 cm(3), and in raloxifene group from 68 cm(3) to 50 cm(3), p<0.05. The difference between the before and after treatment leiomyoma volumes between the two treatments was not statistically significant. H-score of ER expression was significantly lower in gosereline group compared to control group (54.4 versus 113.2, p = 0.001), whereas H-score of PR expression was significantly lower with both gosereline and raloxifene groups compared to control group (64.8 for gosereline versus 94.6 for control, 73.6 for raloxifene versus 94.6 for control, p = 0.001). The bcl-2 expression was higher in both gosereline and raloxifene groups compared to control group (173.7 for gosereline versus 94.7 for control, 179.7 for raloxifene versus 94.7 for control, p = 0.001). The p53 expression was only lower with gosereline than the control group (169.4 versus 205.6, p = 0.001), whereas there was no significant change between the raloxifene group and the control group (201.9 versus 205.6) (p>0.05).

CONCLUSION

Raloxifene was as effective as gosereline in reducing leiomyoma volumes. Decreased PR expression may be a mechanism for tumor growth reduction in raloxifene treatment. In both treatment modalities, the mechanism of shrinkage of leiomyomas could not be increased apoptosis mediated by bcl-2 and p53 expression and should be investigated by further studies.

Comparative Study of Different Dosages of Goserelin in Size Reduction of Myomatous Uteri

STUDY OBJECTIVE

To compare uterine size reduction obtained with three monthly subcutaneous injections of 3.6 mg of goserelin versus a single subcutaneous injection of 10.8 mg.

DESIGN

Prospective, randomized clinical trial (Canadian Task Force classification I).

SETTING

Department of Gynecology and Obstetrics at the Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo.

PATIENTS

Forty-five premenopausal women with uterine leiomyomas and uterine size greater than 600 cm(3) randomized to one of two groups.

INTERVENTION

Group A: 23 women received three monthly subcutaneous 3.6-mg doses of goserelin. Group B: 22 women received a single subcutaneous injection of 10.8 mg of goserelin. Follicle-stimulating hormone (FSH), estradiol, and hemoglobin levels were measured monthly. After 3 months, uterine size was determined by transvaginal and/or abdominal ultrasound.

MEASUREMENTS AND MAIN RESULTS

In group A, mean reduction of uterine size was 43% (426 cm(3)) at the end of treatment. In Group B, mean reduction of uterine size was 54% (494 cm(3)). Serum levels of FSH and estradiol were in postmenopausal range during treatment. Hemoglobin level improvement was equivalent in both groups.

CONCLUSION

Use of single injection of 10.8 mg of goserelin promoted significantly greater reduction in uterine size than three monthly 3.6-mg injections in patients with voluminous uterine leiomyomas.

Non-surgical management of leiomyoma: impact on fertility

PURPOSE OF REVIEW

This review is designed to discuss the literature, published from December 2002 to January 2004, on the non-surgical treatment of fibroid. All established and new modalities are reviewed, and all new developments in the field are discussed. The resulting impact on the treatment of infertility will also be evaluated.

RECENT FINDINGS

In the past year important advances occurred in the medical treatment of uterine fibroids. It was found, in a large randomized trial, that preoperative treatment with gonadotropin-releasing hormone analogue did not improve surgical results or decrease blood loss. However, important strides were made in understanding the molecular biology of the effect of the hormone analogue on fibroids. Other medical therapies investigated include danazol, raloxifene, mifepristone, aromatase inhibitors, and the levonorgestrel-containing intrauterine device. Most promising in terms of long-term usage for reduction of size and symptoms appears to be the combination of gonadotropin-releasing hormone analogue and raloxifene, although selective progesterone receptor modulators may also achieve this aim. However, none avoid producing an anovulatory state that inhibits fertility, and none have been shown to enhance fertility following discontinuation. Uterine artery embolization is another non-surgical technique under intense investigation. The year's literature suggests that while results are comparable with hysterectomy in terms of complication rate and patient satisfaction, there may be important issues for women who wish to undergo the procedure and retain future fertility. Specifically, there is a significant rate of premature ovarian failure, as well as occasional damage to the endometrial vasculature with resulting atrophy and adhesion formation. Improvements in technique, in particular the use of larger and more spherical microspheres for embolization, may reduce these unwanted effects. However, few data exist regarding the course of pregnancy and outcome following embolization.

SUMMARY

A number of non-surgical treatments exist for uterine fibroids, but none has been shown to be of value in the patient desiring future fertility. Myomectomy remains the standard of care for such women, and all other therapies should be designated experimental and limited to appropriate investigational studies.