Differential effect of gonadotropin-releasing hormone analogue treatment on estrogen levels and sulfatase activity in uterine leiomyoma and myometrium

Medical Therapies for Uterine Fibroids - A Systematic Review and Network Meta-Analysis of Randomised Controlled Trials

Background

Uterine fibroids are common, often symptomatic and a third of women need repeated time off work. Consequently 25% to 50% of women with fibroids receive surgical treatment, namely myomectomy or hysterectomy. Hysterectomy is the definitive treatment as fibroids are hormone dependent and frequently recurrent. Medical treatment aims to control symptoms in order to replace or delay surgery. This may improve the outcome of surgery and prevent recurrence.

Purpose

To determine whether any medical treatment can be recommended in the treatment of women with fibroids about to undergo surgery and in those for whom surgery is not planned based on currently available evidence.

Study Selection

Two authors independently identified randomised controlled trials (RCT) of all pharmacological treatments aimed at the treatment of fibroids from a list of references obtained by formal search of MEDLINE, EMBASE, Cochrane library, Science Citation Index, and ClinicalTrials.gov until December 2013.

Data Extraction

Two authors independently extracted data from identified studies.

Data Synthesis

A Bayesian network meta-analysis was performed following the National Institute for Health and Care Excellence—Decision Support Unit guidelines. Odds ratios, rate ratios, or mean differences with 95% credible intervals (CrI) were calculated.

Results and Limitations

A total of 75 RCT met the inclusion criteria, 47 of which were included in the network meta-analysis. The overall quality of evidence was very low. The network meta-analysis showed differing results for different outcomes.

Conclusions

There is currently insufficient evidence to recommend any medical treatment in the management of fibroids. Certain treatments have future promise however further, well designed RCTs are needed.

The Important Roles of Steroid Sulfatase and Sulfotransferases in Gynecological Diseases

Gynecological diseases such as endometriosis, adenomyosis and uterine fibroids, and gynecological cancers including endometrial cancer and ovarian cancer, affect a large proportion of women. These diseases are estrogen dependent, and their progression often depends on local estrogen formation. In peripheral tissues, estrogens can be formed from the inactive precursors dehydroepiandrosterone sulfate and estrone sulfate. Sulfatase and sulfotransferases have pivotal roles in these processes, where sulfatase hydrolyzes estrone sulfate to estrone, and dehydroepiandrosterone sulfate to dehydroepiandrosterone, and sulfotransferases catalyze the reverse reactions. Further activation of estrone to the most potent estrogen, estradiol, is catalyzed by 17-ketosteroid reductases, while estradiol can also be formed from dehydroepiandrosterone by the sequential actions of 3β-hydroxysteroid dehydrogenase-Δ⁴-isomerase, aromatase, and 17-ketosteroid reductase. This review introduces the sulfatase and sulfotransferase enzymes, in terms of their structures and reaction mechanisms, and the regulation and different transcripts of their genes, together with the importance of their currently known single nucleotide polymorphisms. Data on expression of sulfatase and sulfotransferases in gynecological diseases are also reviewed. There are often unchanged mRNA and protein levels in diseased tissue, with higher sulfatase activities in cancerous endometrium, ovarian cancer cell lines, and adenomyosis. This can be indicative of a disturbed balance between the sulfatase and sulfotransferases enzymes, defining the potential for sulfatase as a drug target for treatment of gynecological diseases. Finally, clinical trials with sulfatase inhibitors are discussed, where two inhibitors have already concluded phase II trials, although so far with no convincing clinical outcomes for patients with endometrial cancer and endometriosis.

Treatment of myomas by laparoscopic and laparotomic myomectomy and laparoscopic hysterectomy

The objective of this study was to evaluate the benefits, feasibility and limitations of laparoscopic myomectomy. It was a retrospective review (Canadian Task Force Classification II-2) at a university-based primary treatment centre for endoscopic surgery. The 216 evaluated patients were treated at the Department of Obstetrics and Gynaecology, University of Kiel, between January 1998 and November 2000. Of 216 patients with myomas, 178 (83%) underwent laparoscopic myomectomy, 27 (12%) laparoscopic hysterectomy and 11 (5%) laparotomic myomectomy. The study reviewed the indications and surgical techniques and evaluated the benefits and limitations of laparoscopic myomectomy. Nine patients were selected for Classic Intrafascial Supracervical Hysterectomy (CISH) and 18 for Laparoscopic Assisted Vaginal Hysterectomy (LAVH), i.e. 12% of the patients were selected for laparoscopic hysterectomy. In an additional 11 (5%) patients the laparoscopic approach was difficult because of the location of the myoma and the procedure converted to a laparotomic myomectomy. A total of 178 patients (83%) was treated by laparoscopic myomectomy. The mean hospital stay was three days. No serious complications occurred. Two patients suffered a uterine wound bleeding which was corrected and one patient an abdominal hematoma. Since this study mainly focuses on laparoscopic myomectomies (83%), hysteroscopic myomectomies were evaluated in a separate study. At our institution laparoscopic myomectomy is the first-step treatment for patients with myomatous uteri. Only a small percentage of patients had to undergo a laparotomy (5%) and for 27 patients (12%) hysterectomy proved to be the treatment of choice.

Is aromatase cytochrome P450 involved in the pathogenesis of endometrioid endometrial cancer?

Prospectively, the relationship between androgen levels in the utero-ovarian circulation, aromatase activity in endometrial and body fat tissue, and the presence or absence of endometrioid endometrial cancer was studied in postmenopausal women. In 43 women with endometrioid endometrial cancer and 8 women with a benign gynecological condition, a hysterectomy with bilateral salpingo-oophorectomy was performed. Using tritium water-release assays, aromatase activities in endometrial and body fat tissue were determined and related to the steroid levels from the peripheral and the utero-ovarian venous circulation (estradiol, androstenedione, testosterone) and to the presence or absence of endometrial cancer. Significant aromatase activity was found in both benign and malignant endometrial tissue samples. Aromatase activity in samples of endometrial tissue and in samples of body fat did not correlate with steroid levels in peripheral or utero-ovarian venous blood. Aromatase activity in samples of benign or malignant endometrium did not differ. Remarkably, in four women with mainly poorly differentiated endometrial cancer, very high aromatase activity was found in endometrial tissue. It is likely that multiple pathogenetic pathways exist that eventually lead to the formation of endometrioid endometrial cancer. The local availability of androgens and the finding that aromatase activity is present in both endometrial cancer and benign endometrial tissue support the hypothesis that aromatase activity in the endometrium may play a role in malignant transformation by converting androgens into mitogenic estrogens in the endometrial tissue.