Hormonal therapy for endometriosis: from molecular research to bedside

N-Myc and STAT Interactor is an endometriosis suppressor

In patients with endometriosis, refluxed endometrial fragments evade host immunosurveillance, developing into endometriotic lesions. However, the mechanisms underlying this evasion have not been fully elucidated. N-Myc and STAT Interactor (NMI) have been identified as key players in host immunosurveillance, including interferon (IFN)-induced cell death signaling pathways. NMI levels are markedly reduced in the stromal cells of human endometriotic lesions due to modulation by the Estrogen Receptor beta/Histone Deacetylase 8 axis. Knocking down NMI in immortalized human endometrial stromal cells (IHESCs) led to elevated RNA levels of genes involved in cell-to-cell adhesion and extracellular matrix signaling following IFNA treatment. Furthermore, NMI knockdown inhibited IFN-regulated canonical signaling pathways, such as apoptosis mediated by Interferon Stimulated Gene Factor 3, and necroptosis upon IFNA treatment. In contrast, NMI knockdown with IFNA treatment activated non-canonical IFN-regulated signaling pathways that promote proliferation, including β-Catenin and AKT signaling. Moreover, NMI knockdown in IHESCs stimulated ectopic lesions' growth in mouse endometriosis models. Therefore, NMI is a novel endometriosis suppressor, enhancing apoptosis and inhibiting proliferation and cell adhesion of endometrial cells upon IFN exposure.

Pollution and endometriosis: A deep dive into the environmental impacts on women's health

BACKGROUND

The interaction between pollution and endometriosis is a pressing issue that demands immediate attention. The impact of pollution, particularly air and water pollution, or occupational hazards, on hormonal disruption and the initiation of endometriosis remains a major issue.

OBJECTIVES

This narrative review aims to delve into the intricate connection between pollution and endometriosis, shedding light on how environmental factors contribute to the onset and severity of this disease and, thus, the possible public health policy implications.

DISCUSSION

Endocrine-disrupting chemicals (EDCs) in pollutants dysregulate the hormonal balance, contributing to the progression of this major gynaecological disorder. Air pollution, specifically PM2.5 and PAHs, has been associated with an increased risk of endometriosis by enhancing chronic inflammation, oxidative stress, and hormonal imbalances. Chemical contaminants in water and work exposures, including heavy metals, dioxins, and PCBs, disrupt the hormonal regulation and potentially contribute to endometriosis. Mitigating the environmental impact of pollution is required to safeguard women's reproductive health. This requires a comprehensive approach involving stringent environmental regulations, sustainable practices, responsible waste management, research and innovation, public awareness, and collaboration among stakeholders.

CONCLUSION

Public health policies have a major role in addressing the interaction between pollution and endometriosis in a long-term commitment.

Extensive heterogeneity in the expression of steroid receptors in superficial peritoneal endometriotic lesions

RESEARCH QUESTION

Is the expression of steroid hormone receptors (oestrogen receptor-α and progesterone receptor A/B) and proliferative markers (Bcl-2 and Ki67) uniform among superficial peritoneal endometriotic lesions?

DESIGN

A retrospective cohort study of 24 patients with surgically and histologically confirmed endometriosis. Immunofluorescence was used to determine the proportion of oestrogen receptor-α (ERα), progesterone receptor A/B, Bcl-2 and Ki67 positive cells in 271 endometriotic lesions (defined as endometriotic gland profile/s within an individual region of CD10 stromal immunostaining from a single biopsy) from 67 endometriotic biopsies from 24 patients. Data were analysed to examine associations related to menstrual cycle stage, lesion location and gland morphology.

RESULTS

Oestrogen receptor-α and progesterone receptor A/B expression in superficial peritoneal endometriotic lesions was extremely heterogeneous. Bcl-2 immunostaining in endometriotic lesions was also variable, whereas Ki67 immunostaining was minimal. Menstrual cycle stage associations were limited in steroid hormone receptor and Bcl-2 expression in lesions. Patterns in progesterone receptor A/B and Bcl-2 immunostaining were associated with lesion location. Bcl-2 was differentially expressed, based on lesion gland morphology.

CONCLUSIONS

These data demonstrate considerable diversity in the expression of steroid hormone receptors and Bcl-2 between lesions, even within an individual patient.

Clinical Efficacy, Pharmacokinetics, and Safety of the Available Medical Options in the Treatment of Endometriosis-Related Pelvic Pain: A Scoping Review

BACKGROUND

In this scoping review, we sought to identify published studies evaluating the drugs currently used in the treatment of endometriosis-related pelvic pain, with reflection on their chemical properties, pharmacokinetics, safety profile, and clinical efficacy.

METHODS

A literature search was conducted with the use of the PubMed and EMBASE electronic databases, focusing on identifying articles published in English between January 1990 and 2023.

RESULTS

Based on the included studies, current therapy options for the treatment of endometriosis-related pain identified and reviewed in this article were: (1) non-steroidal anti-inflammatory drugs; (2) combined oral contraceptive (COCs); (3) progestins; (4) gonadotropin-releasing hormone agonists and antagonists; (5) aromatase inhibitors (AIs); (6) selective estrogen and progesterone receptor modulators; and (7) levonorgestrel-intrauterine device.

CONCLUSIONS

Based on the published evidence, clinicians should consider NSAIDs, COCs, and progestins as the first-line medical therapies. Compared with second-line options, such as GnRH agonists/antagonists or AIs, the abovementioned first-line options are well tolerated, efficacious, and exhibit lower overall price. Future research priorities should be to identify novel target therapies and to evaluate the effects of available drugs through different routes of administration.

Anabolic androgenic steroids and cardiomyopathy: an update

Anabolic androgenic steroids (AAS) include endogenously produced androgens like testosterone and their synthetic derivatives. Their influence on multiple metabolic pathways across organ systems results in an extensive side effect profile. From creating an atherogenic and prothrombotic milieu to direct myocardial injury, the effects of AAS on the heart may culminate with patients requiring thorough cardiac evaluation and multi-disciplinary medical management related to cardiomyopathy and heart failure (HF). Supraphysiological doses of AAS have been shown to induce cardiomyopathy via biventricular dysfunction. Advancement in imaging including cardiac magnetic resonance imaging (MRI) and additional diagnostic testing have facilitated the identification of AAS-induced left ventricular dysfunction, but data regarding the impact on right ventricular function remains limited. Emerging studies showed conflicting data regarding the reversibility of AAS-induced cardiomyopathy. There is an unmet need for a systematic long-term outcomes study to empirically evaluate the clinical course of cardiomyopathy and to assess potential targeted therapy as appropriate. In this review, we provide an overview of the epidemiology, pathophysiology and management considerations related to AAS and cardiomyopathy.

Endometriosis Treatment: Role of Natural Polyphenols as Anti-Inflammatory Agents

Endometriosis is an estrogen-dependent common chronic inflammatory disease defined by the presence of extrauterine endometrial tissue that promotes pelvic pain and fertility impairment. Its etiology is complex and multifactorial, and several not completely understood theories have been proposed to describe its pathogenesis. Indeed, this disease affects women's quality of life and their reproductive system. Conventional therapies for endometriosis treatment primarily focus on surgical resection, lowering systemic levels of estrogen, and treatment with non-steroidal anti-inflammatory drugs to counteract the inflammatory response. However, although these strategies have shown to be effective, they also show considerable side effects. Therefore, there is a growing interest in the use of herbal medicine for the treatment of endometriosis; however, to date, only very limited literature is present on this topic. Polyphenols display important anti-endometriotic properties; in particular, they are potent phytoestrogens that in parallel modulates estrogen activity and exerts anti-inflammatory activity. The aim of this review is to provide an overview on anti-inflammatory activity of polyphenols in the treatment of endometriosis.

A Lifelong Impact on Endometriosis: Pathophysiology and Pharmacological Treatment

Endometriosis is a chronic inflammatory disease associated with bothersome symptoms in premenopausal women and is complicated with long-term systemic impacts in the post-menopausal stage. It is generally defined by the presence of endometrial-like tissue outside the uterine cavity, which causes menstrual disorders, chronic pelvic pain, and infertility. Endometriotic lesions can also spread and grow in extra-pelvic sites; the chronic inflammatory status can cause systemic effects, including metabolic disorder, immune dysregulation, and cardiovascular diseases. The uncertain etiologies of endometriosis and their diverse presentations limit the treatment efficacy. High recurrence risk and intolerable side effects result in poor compliance. Current studies for endometriosis have paid attention to the advances in hormonal, neurological, and immunological approaches to the pathophysiology and their potential pharmacological intervention. Here we provide an overview of the lifelong impacts of endometriosis and summarize the updated consensus on therapeutic strategies.

Hormonal drugs for the treatment of endometriosis

In the past, the primary approach for the treatment of endometriosis was represented by surgery; however, after the introduction of non-invasive diagnosis of endometriosis with the development of imaging technologies, medical treatment became the preferred approach, particularly in young patients. Hormonal drugs, by blocking menstruation, are the most effective for the treatment of endometriosis-related pain, independently of phenotype (ovarian, deep, or superficial endometriosis). Gonadotropin-releasing hormone analogs and oral antagonists act on hypothalamus-pituitary-ovary axis inducing iatrogenic menopause, thus reducing dysmenorrhea and all pain symptoms. The side effects, such as hot flushes and bone loss, may be reduced by an add-back therapy. However, the cost in terms of women's health remains high in view of a long-term treatment. Progestins are considered the first-line treatment, highly effective, and with reduced side effects. In addition to the well-known and largely used Norethisterone acetate and Medroxyprogesterone acetate, recently Dienogest has become one of the most used drugs in all endometriosis phenotypes for long-term treatment. Besides, Intrauterine levornogestrel or subcutaneous etonogestrel are valid alternative for long-term treatment.

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease on the background of progesterone resistance. Increased estrogen production, low estrogen metabolization, and altered estrogen receptors (ERs) expression contribute to the hyperestrogenic milieu within endometriotic lesions. Since estrogens play a crucial role in the pathogenesis of the disease, inhibition of estrogen production is one of the main targets of available and emerging drugs.

AREAS COVERED

Firstly, we described the molecular alterations responsible for estrogen dependence. Secondly, we reviewed available and emerging treatments that interfere, through central (gonadotropin-releasing hormone analogs (GnRH-a), GnRH antagonists) or local mechanisms (aromatase inhibitors (AIs), inhibitors of steroid sulfatase (STS) and hydroxysteroid dehydrogenase type 1 (17β-HSD1)), with estrogen dependence. Finally, we focused on emerging treatments targeting ERs (selective estrogen receptor modulators (SERMs), estrogen receptors agonists, and antagonists).

EXPERT OPINION

Available treatments interfering with estrogen pathways exert a contraceptive effect, have hypoestrogenic side effects, and cannot prevent or definitively treat the disease. Preclinical and animal studies are focusing on emerging drugs targeting ERs in order to overcome limitations of available treatments. These treatments may represent a promising option, as they may produce a more specific inhibition of disease activity within endometriotic implants, avoiding prolonged hypoestrogenic status and limiting systemic side effects.

Interferon Signaling in the Endometrium and in Endometriosis

Endometriosis is an estrogen-dependent inflammatory disease that develops in reproductive-aged women who experience pelvic pain and infertility. Even though endometriosis is not a new disease, its molecular etiology has not been clearly elucidated. Defects in the immune system might be one of the factors that promote endometriosis progression. For example, elevated levels of proinflammatory cytokines are associated with endometriosis. Interferon is one of the cytokines that is elevated in endometriotic tissues compared with normal endometrium. Therefore, high interferon levels play a crucial role in endometriosis progression. In addition to endometriosis, however, interferon has a critical role in endometrial function, particularly in the initiation and maintenance of pregnancy. Therefore, this review describes the double-edged sword of interferon signaling in normal endometrial function versus endometriosis progression and also discusses interferon targeting as a new nonhormonal therapy for endometriosis. This approach may increase the efficacy of endometriosis treatment and reduce the adverse effects associated with current hormonal therapy for this disease.

Current status and challenges of drug development for hormonal treatment of endometriosis: a systematic review of randomized control trials

OBJECTIVE

The aim of this systematic review is to summarize the data obtained from randomized controlled trials looking at new pharmacologic treatments for endometriosis published over the last decade with a focus on hormonal therapeutic options for endometriosis-associated pelvic pain (EAPP), excluding studies focusing on fertility.

METHODS

We identified relevant original studies in the English language through a search of the MEDLINE, Scopus, and EMBASE (2012 to present) databases using the appropriate MeSH terms and applying the article type filter 'randomized controlled trials'. A total of 219 records were found during the electronic search. After a detailed evaluation and review of the manuscripts, 11 primary articles met the inclusion criteria. A systematic review of the data was conducted.

RESULTS

This review included several emerging drug therapies for EAPP. Randomized control trials showed promising results with several oral gonadotropin-releasing hormone antagonists (elagolix, relugolix, ASP1707, linzagolix). However, studies of other hormonal agents such as aromatase inhibitors and selective progesterone receptor modulators have not yielded significant or new advantages. Selective estrogen receptor modulators have not been represented in randomized control trials and have failed to demonstrate clinical efficacy.

CONCLUSION

Although numerous novel agents are being investigated for the treatment of endometriosis, there is still no significant progress in the development of curative rather than suppressive drugs. Therefore, further efforts are needed to develop an effective and hopefully curative treatment for this chronic, costly, and overwhelming disease.

Novel pharmacological therapies for the treatment of endometriosis

INTRODUCTION

Endometriosis is a chronic, estrogen-dependent, inflammatory disease associated with pelvic pain, infertility, impaired sexual function, and psychological suffering. Therefore, tailored patient management appears of primary importance to address specific issues and identify the appropriate treatment for each woman. Over the years, abundant research has been carried out with the objective to find new therapeutic approaches for this multifaceted disease.

AREAS COVERED

This narrative review aims to present the latest advances in the pharmacological management of endometriosis. In particular, the potential role of GnRH antagonists, selective progesterone receptor modulators (SPRMs), and selective estrogen receptors modulators (SERMs) will be discussed. We performed a literature search in PubMed and Embase, and selected the best quality evidence, giving preference to the most recent and definitive original articles and reviews.

EXPERT OPINION

Medical therapy represents the cornerstone of endometriosis management, although few advances have been made in the last decade. Most studies have focused on the evaluation of the efficacy and safety of GnRH antagonists (plus add-back therapy in cases of prolonged treatment), which should be used as second-line treatment options in selected cases (i.e. non-responders to first-line treatments). Further studies are needed to identify the ideal treatment for women with endometriosis.

Urinary Tract Endometriosis: How to Predict and Prevent Recurrence after Primary Surgical Excision

STUDY OBJECTIVE

To investigate the clinical and surgical predictors of urinary tract endometriosis (UTE) relapse.

DESIGN

Retrospective single institutional study.

SETTING

Italian multidisciplinary referral center for endometriosis.

PATIENTS

Consecutive patients affected by UTE and surgically treated between January 2016 and March 2020.

INTERVENTION

Surgical excision for UTE. Uni- and multivariate logistic regression analyses were fitted to evaluate clinical and surgical predictors of recurrence.

MEASUREMENTS AND MAIN RESULTS

A total of 105 female age-reproductive patients were enrolled. Median age was 32 years (interquartile range, 24-37). Ureteral involvement was recorded in 53 patients (50.5%), being unilateral and bilateral in 46 patients (43.8%) and 7 patients (6.7%), respectively. Bladder involvement occurred in 52 patients (49.5%). Open surgical approach was performed in 24 cases (22.9%), whereas 30 patients (28.5%) and 51 patients (48.6%) were treated with laparoscopic and robot-assisted approach, respectively. Overall, 53 patients (50.5%) received adjuvant hormonal therapy. At a median follow-up of 39 months (interquartile range, 22-51), 30 patients (28.6%) experienced disease relapse, with 14 recurrences (13.3%) recorded at the level of the urinary tract. At multivariable analysis, age at first surgery <25 years (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.10-1.84; p = .02) and the presence of a concomitant autoimmune disease (OR, 1.45; 95% CI, 1.24-2.17; p = .02) were found as predictors of deep infiltrating endometriosis recurrence, whereas adjuvant postsurgical therapy showed a protective role (OR, 0.83; 95% CI, 0.53-0.98; p = .01).

CONCLUSIONS

Young age (<25 years) and the presence of autoimmune diseases were significant predictors for the development of disease recurrence, whereas adjuvant hormonal therapy showed a protective role.

Hormonal treatments for endometriosis: The endocrine background

Endometriosis is a benign uterine disorder characterized by menstrual pain and infertility, deeply affecting women's health. It is a chronic disease and requires a long term management. Hormonal drugs are currently the most used for the medical treatment and are based on the endocrine pathogenetic aspects. Estrogen-dependency and progesterone-resistance are the key events which cause the ectopic implantation of endometrial cells, decreasing apoptosis and increasing oxidative stress, inflammation and neuroangiogenesis. Endometriotic cells express AMH, TGF-related growth factors (inhibin, activin, follistatin) CRH and stress related peptides. Endocrine and inflammatory changes explain pain and infertility, and the systemic comorbidities described in these patients, such as autoimmune (thyroiditis, arthritis, allergies), inflammatory (gastrointestinal/urinary diseases) and mental health disorders.The hormonal treatment of endometriosis aims to block of menstruation through an inhibition of hypothalamus-pituitary-ovary axis or by causing a pseudodecidualization with consequent amenorrhea, impairing the progression of endometriotic implants. GnRH agonists and antagonists are effective on endometriosis by acting on pituitary-ovarian function. Progestins are mostly used for long term treatments (dienogest, NETA, MPA) and act on multiple sites of action. Combined oral contraceptives are also used for reducing endometriosis symptoms by inhibiting ovarian function. Clinical trials are currently going on selective progesterone receptor modulators, selective estrogen receptor modulators and aromatase inhibitors. Nowadays, all these hormonal drugs are considered the first-line treatment for women with endometriosis to improve their symptoms, to postpone surgery or to prevent post-surgical disease recurrence. This review aims to provide a comprehensive state-of-the-art on the current and future hormonal treatments for endometriosis, exploring the endocrine background of the disease.

Medical and Behavioral Aspects of Adolescent Endometriosis: A Review of the Literature

The majority of young women will experience discomfort associated with menstrual cycles and miss out on education and social opportunities. Endometriosis, the presence of endometrial glands and stroma outside of uterus, is the most common cause of secondary dysmenorrhea and characterized by pain despite treatment with nonsteroidal anti-inflammatory drugs and hormonal agents. The true prevalence of adolescent endometriosis is not clear. Delay in diagnosis leads to persistent pain, affects quality of life, and potentially contributes to disease progression and subfertility. A laparoscopic diagnosis is the gold standard, but the surgical appearance may differ from adults, as endometriotic lesions are usually red or clear, making their identification a challenge for gynecologists who are unexperienced with endometriosis in adolescents. A personalized medical–surgical treatment is regarded as the most effective therapeutic strategy to achieve remission of symptoms, suppress disease progression, and protect future fertility. Studies have demonstrated how adolescent endometriosis negatively affects patients’ quality of life and psychosocial functioning. Development of therapeutic interventions targeting psychosocial function and quality of life is imperative for adolescent patients.

Thai Interest Group for Endometriosis (TIGE) consensus statement on endometriosis-associated pain

This consensus statement has been developed by the Thai Interest Group for Endometriosis (TIGE) for use by Thai clinicians in the diagnosis and management of endometriosis. TIGE is a group of clinical and academic gynaecologists with a particular interest in endometriosis. Endometriosis is an oestrogen-dependent inflammatory disease which causes chronic symptoms such as dysmenorrhoea, chronic pelvic pain, dyspareunia and subfertility, and it is common in reproductive-age women. There is limited overall data on its prevalence in different clinical settings in Thailand, but it is clear that the disease causes significant problems for patients in terms of their working lives, fertility, and quality of life, as well as placing a great burden on national healthcare resources. Decisions about selecting the appropriate treatment for women with endometriosis depend on many factors including the age of the patient, the extent and severity of disease, concomitant conditions, economic status, patient preference, access to medication, and fertility need. Several hormonal treatments are available but no consensus has been reached about the best option for long-term prevention of recurrence. Bearing in mind differences in environment, genetics, and access to the healthcare system, this treatment guideline has been tailored to the particular circumstances of Thai women.

Application of Sol–Gels for Treatment of Gynaecological Conditions—Physiological Perspectives and Emerging Concepts in Intravaginal Drug Delivery

Approaches for effective and sustained drug delivery to the female reproductive tract (FRT) for treating a range of gynaecological conditions remain limited. The development of versatile delivery platforms, such as soluble gels (sol–gels) coupled with applicators/devices, holds considerable therapeutic potential for gynaecological conditions. Sol–gel systems, which undergo solution-to-gel transition, triggered by physiological conditions such as changes in temperature, pH, or ion composition, offer advantages of both solution- and gel-based drug formulations. Furthermore, they have potential to be used as a suitable drug delivery vehicle for other novel drug formulations, including micro- and nano-particulate systems, enabling the delivery of drug molecules of diverse physicochemical character. We provide an anatomical and physiological perspective of the significant challenges and opportunities in attaining optimal drug delivery to the upper and lower FRT. Discussion then focuses on attributes of sol–gels that can vastly improve the treatment of gynaecological conditions. The review concludes by showcasing recent advances in vaginal formulation design, and proposes novel formulation strategies enabling the infusion of a wide range of therapeutics into sol–gels, paving the way for patient-friendly treatment regimens for acute and chronic FRT-related conditions such as bacterial/viral infection control (e.g., STDs), contraception, hormone replacement therapy (HRT), infertility, and cancer.

Comparing endometriotic lesions with eutopic endometrium: time to shift focus?

Endometriosis is a heterogeneous disease in terms of patient symptoms, treatment responsiveness and the presentation of endometriotic lesions. This article explores the histological features of endometriotic lesions, highlighting their sometimes underappreciated heterogeneity. We note the variability in evidence for and against the menstrual cycle responsiveness of lesions and consider the utility of drawing parallels between endometriotic lesions and eutopic endometrium. We ask whether histopathologic features beyond just the presence/absence of endometrial-like glands and/or stroma could help improve disease stratification. At the same time, we acknowledge the desire of many clinicians and patients to avoid invasive surgery thereby limiting the ability to histologically phenotype lesions. The ability to derive clinically useful histological information from endometriotic lesions, in association with patient data, would be invaluable to clinicians to help improve treatment options in such a diverse group of patients. However, in suggesting that a shift in focus may enable the development of a better patient stratification system, we recognise that our wish for a single comprehensive stratification system may be beyond reach for a disease of such diverse presentation.

Assessment of Nerve Fiber Density and Expression of Hormonal Receptors Within Rectosigmoid Endometriosis Nodules

STUDY OBJECTIVE

To assess nerve fiber density and expression of hormone receptors in bowel endometriosis.

DESIGN

Cross-sectional study.

SETTING

Private hospital.

PATIENTS

Women with endometriosis undergoing laparoscopic segmental bowel resection (n = 54).

INTERVENTIONS

Tissue samples were obtained from patients with surgically treated rectosigmoid endometriosis.

MEASUREMENTS AND MAIN RESULTS

The rectosigmoid specimen containing the endometriosis nodule was manually sectioned and divided into 3 areas: core of the nodule, margin of the nodule, and healthy bowel tissue. The intensity of expression of estrogen and progesterone receptors was evaluated by immunohistochemistry and measured according to the Allred score. Nerve fibers were stained by immunohistochemistry using Protein Gene Product 9.5, and the density of nerve fillets was counted and expressed in number/mm². All glandular and stromal cells stained for estrogen; however, glandular cells stained more strongly than stromal cells (61.1% vs 35.2%; p = .01). Most of glandular and stromal cells stained strongly for progesterone receptors (90.7% vs 98.1%; p = .2). The density of nerve fibers was very high in the margin of the nodule (172.22±45.66/mm²), moderate in healthy bowel tissue (111.48±48.57/mm²), and very low in the core of the nodule (7.31±4.9/mm²); p = .01.

CONCLUSION

Both glandular and stromal cells within the rectosigmoid endometriosis nodule express estrogen and progesterone receptors. Higher intensity of expression of estrogen receptors occurs in glandular cells. The density of nerve fibers is extremely high at the nodule margin and very low in the center of the nodule.

Use of dopamine agonists to target angiogenesis in women with endometriosis

Endometriosis requires medical management during a woman's reproductive years. Most treatments aim to create a hypoestrogenic milieu, but for patients wishing to conceive, drugs that allow normal ovarian function are needed. Targeting angiogenesis, a hallmark of the disease, using dopamine agonists (DAs) is a promising strategy for endometriosis treatment. Herein, we review experimental and clinical data that investigate this concept. In experimental models of endometriosis, DAs (bromocriptine, cabergoline, quinagolide) downregulate proangiogenic and upregulate antiangiogenic pathways in inflammatory, endothelial and endometrial cells, blocking cellular proliferation and reducing lesion size. Impaired secretion of vascular endothelial growth factor (VEGF) and inactivation of its receptor type-2 are key events. VEGF inhibition also reduces nerve fiber density in lesions. In humans, quinagolide shows similar effects on lesions, and DAs reduce pain and endometrioma size. Moreover, a 20-fold downregulation of Serpin-1, the gene that encodes for plasminogen activator inhibitor 1 (PAI-1), has been observed after DAs treatment. Pentoxifylline, a PAI-1, increases pregnancy rates in women with endometriosis. Thus, the data support the use of DAs in the medical management of endometriosis to reduce lesion size and pain while maintaining ovulation. A combined approach of DAs and pentoxifylline is perhaps a smart way of targeting the disease from a completely different angle than current medical treatments.

Nanomedicines for Endometriosis: Lessons Learned from Cancer Research

Endometriosis is an incurable gynecological disease characterized by the abnormal growth of endometrium-like tissue, characteristic of the uterine lining, outside of the uterine cavity. Millions of people with endometriosis suffer from pelvic pain and infertility. This review aims to discuss whether nanomedicines that are promising therapeutic approaches for various diseases have the potential to create a paradigm shift in endometriosis management. For the first time, the available reports and achievements in the field of endometriosis nanomedicine are critically evaluated, and a summary of how nanoparticle-based systems can improve endometriosis treatment and diagnosis is provided. Parallels between cancer and endometriosis are also drawn to understand whether some fundamental principles of the well-established cancer nanomedicine field can be adopted for the development of novel nanoparticle-based strategies for endometriosis. This review provides the state of the art of endometriosis nanomedicine and perspective for researchers aiming to realize and exploit the full potential of nanoparticles for treatment and imaging of the disorder.

Liquid chromatography-mass spectrometry applications for quantification of endogenous sex hormones

Liquid chromatography, coupled with tandem mass spectrometry, presents a powerful tool for the quantification of the sex steroid hormones 17-β estradiol, progesterone and testosterone from biological matrices. The importance of accurate quantification with these hormones, even at endogenous levels, has evolved with our understanding of the role these regulators play in human development, fertility and disease risk and manifestation. Routine monitoring of these analytes can be accomplished by immunoassay techniques, which face limitations on specificity and sensitivity, or using gas chromatography-mass spectrometry. LC-MS/MS is growing in capability and acceptance for clinically relevant quantification of sex steroid hormones in biological matrices and is able to overcome many of the limitations of immunoassays. Analyte specificity has improved through the use of novel derivatizing agents, and sensitivity has been refined through the use of high-resolution chromatography and mass spectrometric technology. This review highlights these innovations, among others, in LC-MS/MS steroid hormone analysis captured in the literature over the last decade.

Spatial and temporal changes in the expression of steroid hormone receptors in mouse model of endometriosis

PURPOSE

Endometriosis is recognized as a steroid hormone-dependent disorder. However, controversies exist regarding the status of the steroid hormone receptor expression in endometriotic tissues. The purpose of this study was to determine the ontogeny of cellular changes in the expression of estrogen receptors (ERα, ERβ), G protein-coupled estrogen receptor 1 (GPER1), and progesterone receptors (PRs) in endometriosis using a mouse model.

METHODS

We used the autologous uterine tissue transfer mouse model and studied the mRNA and protein expression of ERα, ERβ, GPER1, and PR in ectopic lesions at 2, 4, and 8 weeks of induction of endometriosis.

RESULT

As compared to endometrium of controls, in the ectopic endometrium, ERα is reduced while ERβ was elevated in stromal cells; however, Gper1 and PR levels are reduced in both stromal and epithelial cells in a time-specific manner. There is a high inter-animal variation in the levels of these receptors in ectopic endometrium as compared to controls; the levels also varied by almost 100-fold within the same lesion resulting in "micro-heterogeneity." The expression of all these receptors also deferred between two lesions from the same animal.

CONCLUSION

In the endometriotic tissue, there is extensive inter-animal and intra-lesion heterogeneity in the expression of ERα, ERβ, GPER1, and PR. These changes are not due to the influence of the peritoneal environment but appear to be tissue intrinsic. We propose that the variable outcomes in hormonal therapy for endometriosis could be possibly due to heterogeneity in the expression of steroid hormone receptors in the ectopic endometrium.

Ulipristal Acetate Prior to Surgery for Endometriosis

Selective progesterone receptor modulators may have a role in the treatment of endometriosis. The aim of this report is to review the effect of ulipristal acetate (UPA) on endometriosis lesions and symptoms in women treated prior to surgery. A pathology review of eutopic endometrium and endometriotic lesions was conducted by two gynecologic pathologists. The main outcome measures reported are pain reduction, amenorrhea, and pathologic progesterone receptor modulator-associated endometrial changes (PAECs). Overall, fifteen women with endometriosis received UPA over a 27-month study period. UPA was administered in an intermittent fashion in the majority of patients while 27% of patients had continuous treatment, between 6 and 24 months. Eleven (73%) patients reported amenorrhea on UPA and 11 (92%) of 12 patients with pain reported pain reduction or resolution. Fourteen patients (93%) proceeded with surgical management. Thirteen (93%) patients underwent excision of suspected endometriosis at surgery. Twelve cases (86%) had concurrent eutopic endometrium specimens and PAEC was identified in 58% (n = 7). Among the 14 cases that underwent surgery, a total of 49 extraovarian sites were sampled. Endometriosis was definitively identified in 31 (63%) of these sites. Three cases (21%) showed morphologic features similar to PAEC within foci of endometriosis. All cases of PAEC-like features in endometriosis also had PAEC in the endometrium. These patients had all noted pain reduction and amenorrhea preoperatively. In conclusion, PAECs may be found in endometriosis lesions in patients treated with UPA. Further prospective investigation is required to evaluate the efficacy and safety of SPRMs in women with endometriosis.

Endometriosis and pain in the adolescent- striking early to limit suffering: A narrative review

Endometriosis, a condition in which uterine tissue grows outside the uterus, is a debilitating disease, affecting millions of women and costing the United States approximately $78 billion annually in pain- related disability. It is also the leading cause of chronic pelvic pain (CPP), which is often unresponsive to existing treatments. Adolescent women with the disease are at particular risk as there are often significant diagnostic delays, which in turn can exacerbate pain. Research and treatment guidelines for adolescents with endometriosis are largely based on studies for adult women due to the limited number of studies focusing on adolescents. The current paper critically reviews the literature as it pertains to endometriosis pathophysiology, mechanisms contributing to CPP, and treatment implications and recommendations with a focus on gaps related to adolescents.

Progesterone and Estrogen Signaling in the Endometrium: What Goes Wrong in Endometriosis?

In the healthy endometrium, progesterone and estrogen signaling coordinate in a tightly regulated, dynamic interplay to drive a normal menstrual cycle and promote an embryo-receptive state to allow implantation during the window of receptivity. It is well-established that progesterone and estrogen act primarily through their cognate receptors to set off cascades of signaling pathways and enact large-scale gene expression programs. In endometriosis, when endometrial tissue grows outside the uterine cavity, progesterone and estrogen signaling are disrupted, commonly resulting in progesterone resistance and estrogen dominance. This hormone imbalance leads to heightened inflammation and may also increase the pelvic pain of the disease and decrease endometrial receptivity to embryo implantation. This review focuses on the molecular mechanisms governing progesterone and estrogen signaling supporting endometrial function and how they become dysregulated in endometriosis. Understanding how these mechanisms contribute to the pelvic pain and infertility associated with endometriosis will open new avenues of targeted medical therapies to give relief to the millions of women suffering its effects.

Advances in the management of endometriosis in the adolescent

PURPOSE OF REVIEW

The present article provides an overview of the molecular mechanisms underlying adolescent endometriosis and advances in both medical and surgical management.

RECENT FINDINGS

Molecular and cellular features of endometriotic lesions differ from eutopic endometrium. There is altered estrogen-mediated cell signaling, proinflammatory pathways develop in the local microenvironment, along with impaired cellular immunity and growth factors, cytokines, and angiogenic factors play a critical role. This leads to proliferation and invasion by ectopic endometrial tissue, and natural clearance by the immune system fails. The inflammation, scarring, and adhesions are symptomatically expressed as dysmenorrhea, pelvic pain, and dyspareunia significantly compromising quality of life.In adolescence, there is a significant delay in diagnosis, often because of physician nonresponsiveness. The social, emotional, and physical impact on adolescents is underestimated. Medical management aimed at cessation of menses is paramount, if surgical management is needed, the goal is maximal excision. A variety of new medications, including GnRH and progesterone antagonists, selective estrogen and progesterone receptor modulators, aromatase inhibitors, statins, angiogenic inhibitors, and botanicals represent future treatment options.

SUMMARY

Early diagnosis of adolescent endometriosis is critical. An understanding of the complex proinflammatory pathways underlying its progression and tailored medical-surgical treatment offers the greatest potential to decrease disease symptomatology.

Anti-inflammatory cytokines in endometriosis

Although the pathogenesis of endometriosis is not fully understood, it is often considered to be an inflammatory disease. An increasing number of studies suggest that differential expression of anti-inflammatory cytokines (e.g., interleukin-4 and -10, and transforming growth factor-β1) occurs in women with endometriosis, including in serum, peritoneal fluid and ectopic lesions. These anti-inflammatory cytokines also have indispensable roles in the progression of endometriosis, including by promoting survival, growth, invasion, differentiation, angiogenesis, and immune escape of the endometriotic lesions. In this review, we provide an overview of the expression, origin, function and regulation of anti-inflammatory cytokines in endometriosis, with brief discussion and perspectives on their future clinical implications in the diagnosis and therapy of the disease.

LIM Kinase 1 Mediates Estradiol Effects on the Phosphorylation of Cofilin1 in Eutopic Endometrial Stromal Cells During the Invasion and Proliferation of Endometriosis

Endometriosis is an estrogen-dependent gynecological disease; however, the mechanism by which estradiol promotes the development of endometriosis, including invasion and proliferation, remains unclear. Estradiol is involved in cell invasion and proliferation by regulating the cytoskeleton. The abnormally high expression of cytoskeletal regulators (LIM kinase 1 [LIMK1] and cofilin1) is closely related to increased invasiveness and proliferation of eutopic endometrial stromal cells from endometriosis patients compared to normal eutopic endometrial cells. The aim of this study was to analyze the role of estradiol during invasion and proliferation through the LIMK1/cofilin1 pathway in the endometrium of women with endometriosis. To address this, primary eutopic endometrial stromal cells were isolated from the uteri of patients with endometriosis and cultured without estradiol. The phosphorylation of cofilin1 was analyzed by western blotting. Cell invasiveness and proliferation were evaluated following LIMK1 knockdown by RNA interference technology. We found that, before LIMK1silencing, the phosphorylation levels of cofilin1 and LIMK1 of eutopic endometrial stromal cells from endometriosis patients treated with estradiol were higher than cells not treated with estradiol ( P < .05 and P < .01, respectively). The total levels of cofilin1 and LIMK1 protein did not change ( P > .05 and P > .05, respectively). After LIMK1 silencing, the phosphorylation of cofilin1 by estradiol was significantly reduced, and invasiveness and proliferation were clearly and concurrently decreased ( P < .05 and P < .05, respectively). Thus, the phosphorylation of cofilin1 by estradiol is mediated by LIMK1, and estradiol is involved in regulating cell invasion and proliferation in endometriotic patients through the LIMK1/cofilin1 pathway.

HORMONAL THERAPY IN WOMEN OF REPRODUCTIVE AGE WITH ENDOMETRIOSIS: AN UPDATE

Medical therapy of endometriosis is under continuous reevaluation. Hereby we updated the drugs currently available or under investigation for the hormonal treatment of endometriosis.

Anti-endometriosis Mechanism of Jiawei Foshou San Based on Network Pharmacology

Jiawei Foshou San (JFS) is the new formula originated from classic Foshou San formula, composed with ligustrazine, ferulic acid, and tetrahydropalmatine. Previously JFS inhibited the growth of endometriosis (EMS) with unclear mechanism, especially in metastasis, invasion, and epithelial-mesenchymal transition. In this study, network pharmacology was performed to explore potential mechanism of JFS on EMS. Through compound-compound target and compound target-EMS target networks, key targets were analyzed for pathway enrichment. MMP-TIMP were uncovered as one cluster of the core targets. Furthermore, autologous transplantation of EMS rat's model were used to evaluate in vivo effect of JFS on invasion, metastasis and epithelial-mesenchymal transition. JFS significantly suppressed the growth, and reduced the volume of ectopic endometrium, with modification of pathologic structure. In-depth study, invasion and metastasis were restrained after treating with JFS through decreasing MMP-2 and MMP-9, increasing TIMP-1. Meanwhile, JFS promoted E-cadherin, and attenuated N-cadherin, Vimentin, Snail, Slug, ZEB1, ZEB2, Twist. In brief, anti-EMS effect of JFS might be related to the regulation of epithelial-mesenchymal transformation, thereby inhibition of invasion and metastasis. These findings reveal the potential mechanism of JFS on EMS and the benefit for further evaluation.

CYP17A1 rs743572 polymorphism might contribute to endometriosis susceptibility: evidences from a case-control study

This case-control study was aimed to evaluate the influence of cytochrome P450 family 17 subfamily A member 1 (CYP17A1) gene rs743572 polymorphism for the susceptibility to endometriosis.Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype rs743572 polymorphism in 143 endometriosis patients and 148 healthy controls. Hardy-Weinberg equilibrium (HWE) test was utilized to detect the representativeness of the study subjects. Association strength was presented by odds ratios (ORs) with corresponding 95% confidence intervals (CIs).Genotype distribution of rs743572 polymorphism was conformed to HWE test both in case and control groups, revealing the good representativeness of our study subjects. Significantly positive association was discovered between rs743572 TT genotype and endometriosis susceptibility (P = .042, OR = 1.952, 95% CI = 1.020-3.736). Rs743572 T allele was more frequently discovered in cases than that in controls, revealing the enhanced susceptibility to endometriosis (P = .041, OR = 1.407, 95% CI = 1.014-1.951). Confounding factors (age and body mass index) were utilized to adjust the results, and then we found that the association strength had no significant changes (TT vs CC, P = .039, OR = 1.961, 95% CI = 1.023-3.742; T vs C, P = .038, OR = 1.413, 95% CI = 1.016-1.957). But we failed to find any obvious association of rs743572 genotypes with endometriosis stages and characteristics.T allele of rs743572 polymorphism might act as a risk factor for endometriosis, although it had no effects on the disease stages and basic features.

Investigational drugs for the treatment of endometriosis, an update on recent developments

INTRODUCTION

Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis.

AREAS COVERED

This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents.

EXPERT OPINION

Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human.

Non-contraceptive benefits of intrauterine levonorgestrel administration: why not?

Levonorgestrel intrauterine systems (LNG-IUS) represent a modern therapy for an array of preexisting gynecological conditions, though they were first marketed in Finland in 1990. However, there are countries in which their use is extremely limited by social and cultural factors. This manuscript describes the possible reasons for this misuse, taking in consideration the clinical noncontraceptive benefits of intrauterine levonorgestrel in routinary practice. Medical diseases in which LNG-IUS represent a treatment include abnormal uterine bleeding, iron-deficiency anemia, endometrial hyperplasia, uterine fibroids, adenomyosis, endometriosis, and coagulopathies. The advantage of reducing the need for more radical treatments such as surgery or hysterectomy is well demonstrated, with remarkable benefits for patients. However, in many countries, surgery is still used as a first-line treatment and there is a need to define who could benefit from a less invasive option. It seems clear that such a reduced use of LNG-IUS depends on factors that imply both patients and practitioners, and that the role of counseling is becoming a key component in the decision-making process to reach the ultimate goal of compliance.

Predictive Biomarkers May allow Precision Therapy of Endometriosis

Introduction

Endometriosis is a chronic inflammatory gynecological disorder that causes pelvic pain. Due to the heterogeneity of the disease, response to any treatment in an individual is variable. We aimed to develop in vitro testing that could be adapted for use in precision therapy for endometriosis. We piloted a personalized medicine approach by identifying predictive biomarkers while determining the effect of bazedoxifene (BZA) and medroxyprogesterone acetate (MPA) on the gene expression of a progesterone receptor (PR), an estrogen receptor (ER), and an aromatase (CYP19A1) enzyme in cells cultured from biopsies of endometriosis patients. The differential expression of the most common molecular targets in endometriosis therapy correlated with cellular response.

Methods

Primary eutopic endometrial stromal cells were cultured from endometrial biopsies obtained in secretory phase from women between 24 and 42 years old with moderate-to-severe endometriosis (stages III and IV). Exclusion criteria included use of hormonal treatments and intrauterine contraception in the 6 months prior to surgery. Cells were treated either with BZA, MPA, or vehicle control. Total RNA was extracted from the treated and untreated cells. Differential expression of genes that are involved in the pathogenesis of endometriosis was determined by quantitative reverse transcriptase-polymerase chain reaction analysis.

Results

After determining the baseline expression levels of PRA/B, ERα and CYP19A1, response to treatment was monitored using Ki-67 as a marker of cell proliferation. MPA was effective in blocking proliferation in the group expressing high levels of PRA/B. Endometrium expressing high levels of CYP19A1 preferentially responded to BZA, a selective estrogen receptor modulator known to block estrogen action in endometrium.

Conclusions

PR expression may predict progestin resistance in endometriosis while CYP19A1 expression may indicate the need to block estrogen signaling.

Efficacy of elagolix in the treatment of endometriosis

INTRODUCTION

Much research has gone into developing medications that can be used to alleviate endometriosis-associated symptoms. In addition to already established medications, a new GnRH antagonist, elagolix, is in development. The novelty of this drug compared to other GnRH antagonists, is its nonpeptide structure, allowing it to be administered orally. Areas covered: We analyzed several Phase I, II and III clinical trials that have evaluated the safety and efficacy of this new medication. Expert opinion: Since many medications have been put on the market and have gained popularity for the treatment of endometriosis-associated symptoms, the demonstration of equality or superiority of effect, tolerability, as well as patient compliance should be assessed when introducing a new drug. While elagolix may have an advantage over established GnRH agonists, in that it does not lead to a 'flare-up' effect, it too, takes a toll on bone mineral density. Nevertheless, studies have shown that this new oral GnRH antagonist is well tolerated, and the side effects have been described as 'mild or moderate'. However, in order to examine whether elagolix can compete with or even surpass established gold-standard medical treatments in this field, further studies that directly compare elagolix to said treatments, might be necessary.

Progesterone receptor modulators for endometriosis

BACKGROUND

Endometriosis is defined as the presence of endometrial tissue (glands and stroma) outside the uterine cavity. This condition is oestrogen-dependent and thus is seen primarily during the reproductive years. Owing to their antiproliferative effects in the endometrium, progesterone receptor modulators (PRMs) have been advocated for treatment of endometriosis.

OBJECTIVES

To assess the effectiveness and safety of PRMs primarily in terms of pain relief as compared with other treatments or placebo or no treatment in women of reproductive age with endometriosis.

SEARCH METHODS

We searched the following electronic databases, trial registers, and websites: the Cochrane Gynaecology and Fertility Group (CGFG) Specialised Register of Controlled Trials, the Central Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO, clinicaltrials.gov, and the World Health Organization (WHO) platform, from inception to 28 November 2016. We handsearched reference lists of articles retrieved by the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) published in all languages that examined effects of PRMs for treatment of symptomatic endometriosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by the Cochrane Collaboration. Primary outcomes included measures of pain and side effects.

MAIN RESULTS

We included 10 randomised controlled trials (RCTs) with 960 women. Two RCTs compared mifepristone versus placebo or versus a different dose of mifepristone, one RCT compared asoprisnil versus placebo, one compared ulipristal versus leuprolide acetate, and four compared gestrinone versus danazol, gonadotropin-releasing hormone (GnRH) analogues, or a different dose of gestrinone. The quality of evidence ranged from high to very low. The main limitations were serious risk of bias (associated with poor reporting of methods and high or unclear rates of attrition in most studies), very serious imprecision (associated with low event rates and wide confidence intervals), and indirectness (outcome assessed in a select subgroup of participants). Mifepristone versus placebo One study made this comparison and reported rates of painful symptoms among women who reported symptoms at baseline.At three months, the mifepristone group had lower rates of dysmenorrhoea (odds ratio (OR) 0.08, 95% confidence interval (CI) 0.04 to 0.17; one RCT, n =352; moderate-quality evidence), suggesting that if 40% of women taking placebo experience dysmenorrhoea, then between 3% and 10% of women taking mifepristone will do so. The mifepristone group also had lower rates of dyspareunia (OR 0.23, 95% CI 0.11 to 0.51; one RCT, n = 223; low-quality evidence). However, the mifepristone group had higher rates of side effects: Nearly 90% had amenorrhoea and 24% had hot flushes, although the placebo group reported only one event of each (1%) (high-quality evidence). Evidence was insufficient to show differences in rates of nausea, vomiting, or fatigue, if present. Mifepristone dose comparisons Two studies compared doses of mifepristone and found insufficient evidence to show differences between different doses in terms of effectiveness or safety, if present. However, subgroup analysis of comparisons between mifepristone and placebo suggest that the 2.5 mg dose may be less effective than 5 mg or 10 mg for treating dysmenorrhoea or dyspareunia. Gestrinone comparisons Ons study compared gestrinone with danazol, and another study compared gestrinone with leuprolin.Evidence was insufficient to show differences, if present, between gestrinone and danazol in rate of pain relief (those reporting no or mild pelvic pain) (OR 0.71, 95% CI 0.33 to 1.56; two RCTs, n = 230; very low-quality evidence), dysmenorrhoea (OR 0.72, 95% CI 0.39 to 1.33; two RCTs, n = 214; very low-quality evidence), or dyspareunia (OR 0.83, 95% CI 0.37 to 1.86; two RCTs, n = 222; very low-quality evidence). The gestrinone group had a higher rate of hirsutism (OR 2.63, 95% CI 1.60 to 4.32; two RCTs, n = 302; very low-quality evidence) and a lower rate of decreased breast size (OR 0.62, 95% CI 0.38 to 0.98; two RCTs, n = 302; low-quality evidence). Evidence was insufficient to show differences between groups, if present, in rate of hot flushes (OR 0.79, 95% CI 0.50 to 1.26; two RCTs, n = 302; very low-quality evidence) or acne (OR 1.45, 95% CI 0.90 to 2.33; two RCTs, n = 302; low-quality evidence).When researchers compared gestrinone versus leuprolin through measurements on the 1 to 3 verbal rating scale (lower score denotes benefit), the mean dysmenorrhoea score was higher in the gestrinone group (MD 0.35 points, 95% CI 0.12 to 0.58; one RCT, n = 55; low-quality evidence), but the mean dyspareunia score was lower in this group (MD 0.33 points, 95% CI 0.62 to 0.04; low-quality evidence). The gestrinone group had lower rates of amenorrhoea (OR 0.04, 95% CI 0.01 to 0.38; one RCT, n = 49; low-quality evidence) and hot flushes (OR 0.20, 95% CI 0.06 to 0.63; one study, n = 55; low quality evidence) but higher rates of spotting or bleeding (OR 22.92, 95% CI 2.64 to 198.66; one RCT, n = 49; low-quality evidence).Evidence was insufficient to show differences in effectiveness or safety between different doses of gestrinone, if present. Asoprisnil versus placebo One study (n = 130) made this comparison but did not report data suitable for analysis. Ulipristal versus leuprolide acetate One study (n = 38) made this comparison but did not report data suitable for analysis.

AUTHORS' CONCLUSIONS

Among women with endometriosis, moderate-quality evidence shows that mifepristone relieves dysmenorrhoea, and low-quality evidence suggests that this agent relieves dyspareunia, although amenorrhoea and hot flushes are common side effects. Data on dosage were inconclusive, although they suggest that the 2.5 mg dose of mifepristone may be less effective than higher doses. We found insufficient evidence to permit firm conclusions about the safety and effectiveness of other progesterone receptor modulators.