Effects of the levonorgestrel-releasing intrauterine system on cell proliferation, Fas expression and steroid receptors in endometriosis lesions and normal endometrium

Is endometriosis due to evolutionary maladaptation?

Similar to diabetes and unlike many pathogen-induced diseases, endometriosis is likely a result of maladaptation to the evolutionary heritage of humans. The objective of this article is to review the literature and improve understanding of the evolutionary factors behind endometriosis, leading to more effective prevention and treatment approaches. In primates, spontaneous decidualization of the endometrium evolved to ensure optimal implantation of a limited number of early embryos, unlike many non-primates which depend on early embryos to induce decidualization and subsequent pregnancy. Spontaneous decidualization results in menstrual bleeding when embryo implantation does not occur, and endometriosis is commonly believed to be caused by retrograde menstruation. Although direct evidence is lacking, it is likely that hunter-gatherer women experienced fewer menstrual periods due to pregnancy shortly after menarche, followed by repeated pregnancies and lactation. However, the mismatch between the evolved uterine physiology and rapid societal changes has led to modern women delaying pregnancy and experiencing numerous menstrual periods, potentially increasing the incidence of endometriosis. The symptoms of endometriosis are often managed by suppressing menstruation through systemic hormonal treatments, but these may have side effects. For patients with a family history of endometriosis or in the early stages of the disease, intrauterine devices releasing progesterone locally could prevent uterine bleeding and the development of endometriosis while preserving fertility and minimizing side effects.

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.

Progesterone Resistance in Endometriosis: Current Evidence and Putative Mechanisms

Endometriosis is an estrogen-dependent disease characterized by the growth of endometrial-like tissue outside the uterus. Progestins are currently the most commonly used treatment for endometriosis because of their excellent therapeutic effects and limited side effects. However, progestins have been unsuccessful in some symptomatic patients. The inability of the endometrium to respond properly to progesterone is known as progesterone resistance. An increasing body of evidence suggests the loss of progesterone signaling and the existence of progesterone resistance in endometriosis. The mechanisms of progesterone resistance have received considerable scholarly attention in recent years. Abnormal PGR signaling, chronic inflammation, aberrant gene expression, epigenetic alterations, and environmental toxins are considered potential molecular causes of progesterone resistance in endometriosis. The general objective of this review was to summarize the evidence and mechanisms of progesterone resistance. A deeper understanding of how these mechanisms contribute to progesterone resistance may help develop a novel therapeutic regimen for women with endometriosis by reversing progesterone resistance.

The role of levonorgestrel-releasing intrauterine system for recurrence prevention after conservative surgery among patients with coexistent ovarian endometrioma and diffuse adenomyosis: A retrospective case control study with long-term follow up

BACKGROUND

When ovarian endometrioma coexist with adenomyosis, the risk of postoperative recurrence increased. How is the effect of levonorgestrel-releasing intrauterine system (LNG-IUS) on symptomatic recurrence for those patients was unknown.

METHODS

This study retrospectively analyzed 119 women with coexistent endometrioma and diffuse adenomyosis who received laparoscopic excision of pelvic endometriosis from January 2009 to April 2013. Women were categorized into two groups: intervention group with LNG-IUS and control group with expectant observation after surgery. Data were compared in terms of preoperative history, laboratory and intraoperative findings, and clinical outcomes during follow-up, including pain regression, changes in uterine volume and recurrence.

RESULTS

During a median 79 months (range, 6-107) of follow-up, patients with LNG-IUS experienced a significantly lower symptomatic recurrence of either ovarian endometrioma or dysmenorrhea (11.1% vs. 31.1%, p = 0.013), compared with women under expectant observation by Kaplan-Meier survival analysis (χ² = 5.448, p = 0.020) and Cox univariate assessment (hazard ratio of 0.336, 95% confidence interval 0.128-0.885, p = 0.027). Patients treated with LNG-IUS demonstrated a more prominent reduction in uterine volume (-14.1 ± 20.9 vs. 8.7 ± 48.8, p = 0.003) and higher percentage of complete pain remission (95.6% vs. 86.5%). For multivariate analysis, use of LNG-IUS (aHR 0.159, 95%CI 0.033-0.760, p = 0.021) and severity of dysmenorrhea (aHR 4.238, 95%CI 1.191-15.082, p = 0.026) were two independent factors associated with overall recurrence.

CONCLUSION

Postoperative insertion of LNG-IUS may prevent recurrence in symptomatic women with comorbidity of ovarian endometrioma and diffuse adenomyosis.

Effects of Ethinyl Estradiol in Combined Oral Contraceptives on Cell Proliferation and Apoptosis in Ectopic Endometrial Tissue: A Randomized Controlled Study

Objective: Since endometriosis is an estrogen-dependent disease; therefore, combined oral contraceptives (COCs) may not be the best choice for the treatment of endometriosis. The objective of the present study was to investigate the effects of ethinyl estradiol (EE) and desogestrel (DSG) in COCs on cell proliferation and apoptosis in ectopic endometrial tissue as compared to DSG alone. Materials and methods: Forty-five women of reproductive age with at least one endometriotic cyst were recruited into this single-blind randomized controlled trial study and randomly divided equally into three groups. EE-DSG and DSG groups received EE (0.03 mg) and DSG (0.15 mg) or DSG alone daily for 28-35 days before surgery. The control group was prescribed nothing. Endometriotic cyst tissues were collected during ovarian cystectomy for immunohistochemistry. Results: Levels of Ki-67 positive cells in the ectopic endometrial tissue of the EE-DSG group were significantly higher than the DSG group (median [IQR]; 1.4[1.2] vs 0.6 [0.7], P <0.016). There were significantly more TUNEL-positive cells in the EE-DSG group compared to the DSG group (median [IQR]; 2.8[0.7] vs 1.8[1.4], P < 0.016, respectively). Moreover, the number of TUNEL-positive cells in the EE-DSG and DSG groups were significantly higher than the control (median [IQR]; 2.8[0.7] vs 0.2[0.2] and 1.8[1.4] vs 0.2[0.2], P <0.016). The levels of cells that positively stained for Bcl2 were not different among all groups. Conclusion: Progestin alone increased cell apoptosis in ectopic endometria. However, concurrent EE in COCs enhanced proliferation and promoted a greater apoptotic effect in ectopic endometria compared to progestin alone.

Medical management of endometriosis

INTRODUCTION

Endometriosis is a benign gynecologic disorder that is defined as functional endometrial tissue outside of the uterine cavity. It is an estrogen-dependent, inflammatory disease that leads to symptoms of pelvic pain, dysmenorrhea, dyspareunia, and infertility, occurring in 6-10% of reproductive aged women. The severity of the disease ranges from asymptomatic to debilitating symptoms that have a major impact on women's lives. It is a chronic, recurrent disease, frequently requiring long term management until menopause and beyond. It is considered a chronic disorder that is managed with surgery, medical treatment, and oftentimes, both. Current medical therapy for endometriosis is considered suppressive of the disease, rather than curative. Fortunately, many patients do experience improvement and control of their symptoms with medical therapy. However, long-term efficacy of the medical treatments is often limited by side effects and the cost of therapy, and symptoms do tend to recur after discontinuation of these medications.

AREAS COVERED

This review summarizes our understanding of the pathogenesis of endometriosis and provides more in-depth discussion of specific medical management options used to treat endometriosis, including mechanism of action and side effects. It also provides recommendations on strategy with a forward look to novel endometriosis treatments in the future.

EXPERT OPINION

The authors emphasize that endometriosis is a chronic disorder requiring long term medical therapy. Early diagnosis of endometriosis is key in preventing severe, debilitating symptoms and progression of disease. By utilizing our current knowledge of the pathophysiology of endometriosis and by correctly implementing currently available medical and surgical therapies we can significantly reduce the physical, psychosocial and financial burden of this chronic, recurrent and indolent disease. Current available medications are suppressive therapies, but the authors are looking forward to future therapies that can effectively cure or at least control endometriosis with minimal side effects. Future research should continue to look for the genetic trigger for endometriosis which can lead us to its underlying pathogenesis and eventually a cure or prevention.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

Progesterone receptor ligands for the treatment of endometriosis: the mechanisms behind therapeutic success and failure

BACKGROUND

Despite intense research, it remains intriguing why hormonal therapies in general and progestins in particular sometimes fail in endometriosis.

OBJECTIVE AND RATIONALE

We review here the action mechanisms of progesterone receptor ligands in endometriosis, identify critical differences between the effects of progestins on normal endometrium and endometriosis and envisage pathways to escape drug resistance and improve the therapeutic response of endometriotic lesions to such treatments.

SEARCH METHODS

We performed a systematic Pubmed search covering articles published since 1958 about the use of progestins, estro-progestins and selective progesterone receptor modulators, to treat endometriosis and its related symptoms. Two reviewers screened the titles and abstracts to select articles for full-text assessment.

OUTCOMES

Progesterone receptor signalling leads to down-regulation of estrogen receptors and restrains local estradiol production through interference with aromatase and 17 beta-hydroxysteroid dehydrogenase type 1. Progestins inhibit cell proliferation, inflammation, neovascularisation and neurogenesis in endometriosis. However, progesterone receptor expression is reduced and disrupted in endometriotic lesions, with predominance of the less active isoform (PRA) over the full-length, active isoform (PRB), due to epigenetic abnormalities affecting the PGR gene transcription. Oxidative stress is another mechanism involved in progesterone resistance in endometriosis. Among the molecular targets of progesterone in the normal endometrium that resist progestin action in endometriotic cells are the nuclear transcription factor FOXO1, matrix metalloproteinases, the transmembrane gap junction protein connexin 43 and paracrine regulators of estradiol metabolism. Compared to other phenotypes, deep endometriosis appears to be more resistant to size regression upon medical treatments. Individual genetic characteristics can affect the bioavailability and pharmacodynamics of hormonal drugs used to treat endometriosis and, hence, explain part of the variability in the therapeutic response.

WIDER IMPLICATIONS

Medical treatment of endometriosis needs urgent innovation, which should start by deeper understanding of the disease core features and diverse phenotypes and idiosyncrasies, while moving from pure hormonal treatments to drug combinations or novel molecules capable of restoring the various homeostatic mechanisms disrupted by endometriotic lesions.

Effect of pretreatment with a levonorgestrel-releasing intrauterine system on IVF and vitrified-warmed embryo transfer outcomes in women with adenomyosis

RESEARCH QUESTION

Does the use of a levonorgestrel-releasing intrauterine system (LNG-IUS) improve the ongoing pregnancy rate of vitrified-warmed embryo transfer in women with adenomyosis undergoing IVF?

DESIGN

This retrospective study included 358 women with adenomyosis undergoing IVF. Of these, 134 women were enrolled in the LNG-IUS group and another 224 women were in the control group. All women were screened for adenomyosis by transvaginal ultrasound and magnetic resonance imaging (MRI). There was no significant difference in the ages of women, FSH, cause of infertility, body mass index, total dose of gonadotrophin used and number of oocytes collected between the two groups. All comparisons performed were between patients undergoing vitrified-warmed embryo transfer.

RESULTS

Statistical differences were found in the ongoing pregnancy rates (41.8% vs 29.5%, P = 0.017) between the LNG-IUS group and control group. Logistic regression analysis showed that the odds ratio (OR) of ongoing pregnancy was significantly increased with LNG-IUS usage (adjusted OR = 1.628, 95% confidence interval 1.011-2.622). Also, differences were found in implantation rates (32.1% vs 22.1%, P = 0.005) and clinical pregnancy rates (44% versus 33.5%, P = 0.045) between the LNG-IUS group and control group.

CONCLUSIONS

The results of this study offer some support for evaluating the effect of pretreatment with LNG-IUS in women with adenomyosis in future randomized controlled trials.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

Differential expressions of estrogen and progesterone receptors in endometria and cyst walls of ovarian endometrioma from women with endometriosis and their responses to depo-medroxyprogesterone acetate treatment

BACKGROUND

Depo-medroxyprogesterone acetate (DMPA) is an injectable progestin contraceptive that provides a highly effective reduction of pelvic pain in women with endometriosis. Despite its wide use to treat pain associated with endometriosis, its precise mechanisms of action remain unclear. The aims of this study were to investigate the differential expressions of estrogen receptors (ERs), and progesterone receptors (PRs) in endometria and ovarian endometrioma cyst walls of women with endometriosis with and without DMPA treatment.

METHODS

Endometria and cyst walls of endometrioma were obtained from 25 to 45 year-old women who suffered from endometriosis and had ovarian endometrioma with the size ≥3 cm. The expression levels of ERs and PRs and the numbers of ER- and PR-positive cells before and after treatment with DMPA were evaluated by Western blot, real-time PCR, and immunohistochemistry.

RESULTS

The levels of ERα and ERβ expression, their corresponding mRNAs, and numbers of ERα- and ERβ-immunoreactive cells in stroma and glands of endometria of the DMPA group were significantly decreased when compared with those of the untreated groups (p < 0.05). In contrast, the levels of PRA/B expression and numbers of PRA/B positive cells in stroma and number of PRB positive cells in stroma and endometrial glands were significantly increased in endometria of the DMPA group when compared with those of the untreated groups. However, in cyst wall the expression levels of these proteins, their corresponding mRNAs, and immonoractive cells were low compared to those in endometria, and DMPA-treatment did not cause any significant changes in these parameters.

CONCLUSION

These data indicated that DMPA could upregulate the expressions of PRA/B and down-regulate ERα and ERβ in endometria but not in cyst walls from women with endometriosis.

Current understanding on pharmacokinetics, clinical efficacy and safety of progestins for treating pain associated to endometriosis

INTRODUCTION

Endometriosis is a chronic estrogen and progestogen responsive inflammatory disease associated with pain symptoms and infertility. The medical therapy of endometriosis aims to induce decidualization within the hormonally dependent ectopic endometrium, and it is often administered to ameliorate women' pain symptoms or to prevent post-surgical disease recurrence. A variety of progestins have been used in monotherapy for the medical management of women with endometriosis. Areas covered: This review aims to offer the reader a complete overview of pharmacokinetic (PK) and clinical efficacy of progestins for the treatment of endometriosis. Expert opinion: Each progestin has a distinct PK parameters and pharmacodynamics affinity not only for progesterone receptor, but also for other steroid receptors, such as estrogen, androgen, and glucocorticoid. Moreover, progestins can also be delivered in different formulations. All these characteristics influence their final biological effect. Randomized, controlled, non-blinded studies support the use of oral progestin-only treatment for pelvic pain associated with endometriosis. Currently, the only two progestins approved by Food and Drug Administration (FDA) for the treatment of endometriosis are norethindrone acetate (NETA) and depot medroxyprogesterone acetate (DMPA).

Characteristics of Women with Recurrent Endometriosis Pain after Laparoscopy and Levonorgestrel Intrauterine Device Placement

Introduction

The levonorgestrel (LNG)-intrauterine device (IUD) is effective for many, but not all, women with endometriosis in managing pelvic pain. The aim of this study was to explore the characteristics associated with recurrent endometriosis pain within 12 months after operative laparoscopy and LNG-IUD placement.

Methods

This retrospective case series was performed at a university-affiliated infertility and reproductive surgery practice and included women who underwent operative laparoscopy and LNG-IUD placement by a single surgeon from January 1, 2012 to October 7, 2015 (n = 32). Within 12 months post-operatively, the primary surgeon assessed pain reported by the patient and prescribed adjunctive oral hormonal therapy for recurrent pain symptoms. Data were collected using the patients’ electronic medical records. The main outcome was the presence of recurrent endometriosis pain within 12 months after operative laparoscopy with LNG-IUD placement.

Results

Of the 32 women who underwent laparoscopy and LNG-IUD placement, 26 presented for follow-up (81.2%) within 12 months, 15 of whom (57.7%) reported recurrent pain. The odds of poor pain control were higher among the women who were obese, among those who had undergone prior laparoscopy, and among those with a history of asthma, depression, or headaches.

Conclusions

The optimal management of endometriosis-related pain is highly patient-specific, and poor response to LNG-IUD may be associated with having had a prior laparoscopy, obesity, and certain medical comorbidities.

Dienogest reduces proliferation, NGF expression and nerve fiber density in human adenomyosis

OBJECTIVES

To evaluate the in vivo effect of dienogest on proliferation, apoptosis, aromatase expression, vascular density, nerve growth factor (NGF) expression and nerve fiber density in human adenomyosis tissue.

STUDY DESIGN

Twelve women who underwent hysterectomy for adenomyosis were enrolled. Six patients received dienogest treatment prior to hysterectomy (dienogest group), and age-matched six patients who had not received any hormonal treatment for ≥3 months before surgery (control group). Cell proliferation, vascular and nerve fiber density in adenomyosis tissue were evaluated by staining for Ki67, von Willebrand factor and PGP9.5, respectively. Apoptosis was detected using the TUNEL assay. The expression aromatase and NGF were evaluated by staining for corresponding antibodies.

RESULTS

The proportion of Ki67 positive epithelial cells was significantly lower in samples from dienogest-treated patients in comparison with controls (p<0.05). The density of blood vessels in adenomyosis was marginally lower in the dienogest group in comparison with controls but statistical significance was not reached (p=0.07). The intensity of NGF expression and the density of nerve fibers were significantly lower in the dienogest group compared with controls (p<0.05 for both).

CONCLUSION

This study demonstrates that adenomyosis, taken from patients treated with dienogest, shows remarkable histological features, such as reductions in proliferation, NGF expression and nerve fiber density. These findings indicate the impact of dienogest on local histological events, and explains its therapeutic effect on adenomyosis.

Immunohistochemical Analysis of the Effect of Dienogest on Ovarian Endometriotic Cysts

Dienogest is a novel progestin with potent oral progestational activity that inhibits the clinical symptoms of endometriosis. We herein evaluated the effect of dienogest on ovarian endometriotic cysts via immunohistochemistry. Ovarian endometriotic cyst specimens were collected from 12 patients treated with dienogest and 20 patients not treated with hormones (controls). The expression of estrogen receptor (ER)-α, progesterone receptor A (PRA), and Ki-67 was studied by immunohistochemistry. As compared with the controls, the cell proliferation index was significantly reduced in both epithelial and stromal cells of the endometriotic cysts following the use of dienogest (P = 0.022 and P = 0.004, respectively). However, there was no significant difference between endometriotic cysts with and without the use of dienogest in the expressions of ER-α and PRA in the epithelial and stromal cells. Irrespective of the use of dienogest, the expression levels of ER-α and PRA in the epithelial cells were low (median: 32% and 8%, respectively). Conversely, the expression levels of ER-α and PRA in the stromal cells were well preserved (median: 68% and 92%, respectively). In the controls, there was no significant difference between endometriotic cysts in the expression levels of Ki-67, ER-α and PRA in epithelial and stromal cells during the proliferative and secretory phases. The finding of a reduction in the cell proliferation index by the use of dienogest with no change in the expressions of hormonal receptors may not support the direct progestational effect of dienogest on ovarian endometriotic cysts.

Differential mRNA expression profiling in ovarian endometriotic tissue with versus without leuprolide acetate treatment

AIM

Leuprolide acetate, an analog of gonadotropin-releasing hormone (GnRH), regresses endometriotic tissue and reduces pain, resulting in clinical improvement upon treatment. The molecular mechanisms involved in the regression of endometriotic tissue, however, remain to be elucidated. In this study, we performed genome-wide gene expression profiling of clinical specimens of ovarian endometrioma to obtain insight into the effects of leuprolide acetate treatment.

METHODS

We obtained clinical samples from nine normal eutopic endometrium tissues, eight ovarian endometriotic tissues, and 12 leuprolide acetate-treated endometriotic tissues. We compared the gene expression profiles of the three groups using Affymetrix GeneChip Human genome arrays and bioinformatic analysis, including molecular concept analysis.

RESULTS

Leuprolide acetate-treated endometriotic tissue showed downregulated genes associated with the biological functions of steroid hormone regulation, cell proliferation, inflammation, and intracellular signaling. These genes included PTGDS, GRP, APLP2, PLTP, and FGFRL1. In contrast, genes upregulated by leuprolide acetate treatment were associated with cell growth inhibition and apoptosis. These genes included CARD11 and USP18.

CONCLUSIONS

These preliminary results based on GeneChip analysis suggest that leuprolide acetate treatment induces a modulation of gene expression that allows for cooperative alterations in disease state. This study gives new insight into the effects of leuprolide acetate treatment. Further investigations with quantitative reverse transcription-polymerase chain reaction and immunohistochemistry are needed to validate this study and to explore new therapeutic targets and biomarkers of endometriosis.

Emerging therapy for endometriosis

INTRODUCTION

Endometriosis is a chronic disease manifested by pain and infertility due to ectopic implantation of endometrial glands and stroma causing inflammation. Treatment of endometriosis utilizes a significant amount of health-care resources and requires chronic therapy. Management involves a combination of surgical and medical interventions and requires long-term treatment to avoid repeated surgeries.

AREAS COVERED

Whereas medical therapies exist for management of endometriosis-related pain, each class has its limitations including side effects, cost, and known duration of relief of symptoms. Development of effective, well-tolerated medical therapies that are appropriate for long-term use is crucial to provide adequate treatment for this chronic disease. This review discusses the various medical therapies available, their limitations, and emerging therapies being developed to address many of these concerns.

EXPERT OPINION

The authors recommend chronic suppressive therapy for management of endometriosis symptoms, particularly in the postoperative setting. Empiric treatment is appropriate for those patients without evidence of severe disease. Currently available option may not be effective for nor tolerated by all patients. Newer compounds, including gonadotropin-releasing antagonists and aromatase inhibitors combined with hormonal contraceptives, offer possible alternatives to currently available therapies.

Hormonal treatment for severe hydronephrosis caused by bladder endometriosis

The incidence of endometriosis cases involving the urinary system has recently increased, and the bladder is a specific zone where endometriosis is most commonly seen in the urinary system. In the case presented here, a patient presented to the emergency department with the complaint of side pain and was examined and diagnosed with severe hydronephrosis and bladder endometriosis was determined in the etiology. After the patient was pathologically diagnosed, Levonorgestrel-Releasing Intrauterine System (LNG-IUS) was administered to the uterine cavity. At the 12-month follow-up, endometriosis was not observed in the cystoscopy and symptoms had completely regressed. Hydronephrosis may be observed after exposure of the ureter, and silent renal function loss may develop in patients suffering from endometriosis with bladder involvement. For patients with moderate or severe hydronephrosis associated with bladder endometriosis, LNG-IUS application may be separately and successfully used after conservative surgery.

New trends of progestins treatment of endometriosis

The management of endometriosis with OC or progestins is generally safe, effective and well-tolerated and should constitute the first line of medical treatment in symptomatic patients who do not want to have children. Progestins, synthetic progestational agents, have been used in the management of symptomatic endometriosis both as primary therapy and as an adjunct to surgical time. A variety of oral agents have been employed in this regard and investigators have demonstrated differing degrees of benefit. The lack of a standardized instrument to evaluate painful symptoms makes comparative analysis more difficult. Concern about efficacy and side effect has pushed the research on the development of new well-tolerated drugs and to develop new administration routes to minimize general side effects. Aim of the present review is to present the results of clinical studies on new trends of progestins in the treatment of endometriosis.

Dienogest reduces proliferation, aromatase expression and angiogenesis, and increases apoptosis in human endometriosis

Dienogest is a novel progestin that is highly selective for progesterone receptors and inhibits endometriosis. However, it remains unknown how the administration of dienogest to patients with endometriosis impacts on their lesion tissues. The aim of this study was to evaluate the in vivo effect of dienogest on endometriosis tissue. We collected endometrioma tissues from patients treated with dienogest (N = 7) or not treated (N = 11, controls). Cell proliferation, aromatase expression and blood vessel density were evaluated by staining for Ki67, aromatase and the von Willebrand factor, respectively. Apoptosis was detected using the TUNEL assay. The proportion of Ki67 and aromatase positive epithelial cells was significantly lower in the dienogest group than in controls (p < 0.05, respectively). The number of TUNEL positive cells was significantly higher in the dienogest group (p < 0.05). The density of blood vessels in endometrioma was marginally lower in the dienogest group compared with controls (p = 0.20). Our study demonstrates that endometrioma taken from patients treated with dienogest show remarkable histological features such as reduction of proliferation, aromatase expression and angiogenesis, and increase of apoptosis. This study clarified the impact of dienogest on local histological events that explain its therapeutic effect on endometriosis.

Analysis of the levonorgestrel-releasing intrauterine system in women with endometriosis

Objectives

To compare the efficacy, safety and other clinical benefits of the levonorgestrel-releasing intrauterine system (LNG-IUS) and gonadotropin-releasing hormone analogues (GnRH-a) in women with endometriosis.

Methods

A systematic search was carried out using the Cochrane Central Register of Controlled Trials, PubMed, MEDLINE™ and EMBASE databases for all randomized controlled trials (RCTs) that evaluated the use of the LNG-IUS and GnRH-a in premenopausal women with endometriosis.

Results

Five RCTs studies were identified. A meta-analysis showed that, in women with endometriosis, both the LNG-IUS and GnRH-a reduced pain visual analogue scale scores (weighted mean difference [WMD] 0.03 [95% confidence interval [CI] −0.53, 0.59]), serum levels of CA125 (WMD −12.29 [95% CI −29.90, 3.32]), and American Society of Reproductive Medicine staging scores (WMD 1.10 [95% CI −27.98, 30.18]). Psychological and general wellbeing index scores were increased (WMD 1.50 [95% CI −6.19, 9.19]). Levels of low-density lipoprotein cholesterol were also significantly reduced in patients treated with the LNG-IUS (WMD 39.30 [95% CI 6.74, 71.86]).

Conclusions

The LNG-IUS had clinical efficacy equivalent to that of GnRH-a but may have some clinical advantages over GnRH-a in the treatment of endometriosis-associated symptoms. These observations will require further verification in additional studies employing larger patient populations.

Endometriosis: hormone regulation and clinical consequences of chemotaxis and apoptosis

BACKGROUND

The recruitment of immune cells by chemokines and the regulation of endometrial cell apoptosis are critical aspects of endometriosis biology. Here, we review the local (paracrine) and systemic hormone (endocrine) modulation of these two specific, but highly related phenomena.

METHODS

We searched Pubmed for items published in English between September 1991 and September 2011 and selected the studies evaluating the effects of hormones on chemokines or apoptosis in normal human endometrium and endometriosis.

RESULTS

Estradiol has proinflammatory and antiapoptotic effects in endometrial cells, and these effects appear to be exacerbated in women with endometriosis. In these women, physiological estradiol concentrations are able to induce an enhanced inflammatory response mediated by local chemokine production and to reinforce mechanisms of cell survival mediated by extracellular signal-regulated kinases and Bcl-2. The main effect of progestogens is to inhibit interleukin-8 and other chemokines in stromal cells from both eutopic and ectopic endometrium. Progesterone is also effective in inducing apoptosis in endometrial and endometriotic cells through the inhibition of Bcl-2 and nuclear factor-κB.

CONCLUSIONS

Estrogens and progestogens modulate chemotaxis and apoptosis in human endometrium and endometriotic cells and tissues. These endocrine and paracrine pathways are perturbed in women with endometriosis, contributing to inflammatory responses, abnormal tissue remodeling, therapeutic refractoriness and disease persistence. Ultimately, they promote adhesion formation and the clinical symptoms of pelvic pain and infertility. A more detailed understanding of the molecular mechanisms involved will offer new opportunities for novel pharmacological strategies to diagnose and treat endometriosis.

Long-term regression of experimental endometriosis in a rat model treated with local application of levonorgestrel-loaded biodegradable microspheres

BACKGROUND

A previous study demonstrated that local application of levonorgestrel-loaded polylactic acid microspheres (LNG microspheres) resulted in significant regression of endometriotic cysts in a rabbit model for 6 months without disturbing the metabolic parameters or ovarian function. In order to investigate the feasibility of local application of LNG microspheres as a long-term maintenance treatment for endometriosis, the suppressive effect of a single intra-cystic injection of LNG microspheres was studied for 1 year in a rat model.

METHODS AND RESULTS

Twenty four rats with experimental endometriotic cysts were randomized to be treated with a single intra-cystic injection of LNG microspheres (n = 8); 6-month GnRH agonist (GnRHa, n = 8) or control (n = 8). Intra-cystic injection of LNG microspheres and GnRHa treatment caused comparable regression and atrophy in endometriotic cysts in the first 6 months. Compared with the control, the wet weight of the endometriotic cysts was significantly lower in both groups at Month 6 but by Month 12 only remained low in the LNG microspheres group (P < 0.01). The immunostaining of estrogen receptors (ERs) in both the epithelium and stroma and progesterone receptors (PRs) in the stroma was significantly weakened in the LNG microspheres group at Month 6 and was not fully restored at Month 12 (P < 0.01). Metabolic parameters and estrous cycle were not disturbed by local application of LNG microspheres.

CONCLUSIONS

In a rat endometriosis model, the suppressive effect of a single intra-cystic injection of LNG microspheres was comparable to that of GnRHa, and was maintained for 1 year. The down-regulation of ERs and PRs might serve as possible mechanism of long-term effectiveness.

Emerging indications for the levonorgestrel-releasing intrauterine system (LNG-IUS)

The levonorgestrel intrauterine system (LNG-IUS), originally designed for long-term contraceptive use, has been on the Scandinavian market for approximately 20 years. Novel clinical indications for the LNG-IUS, derived mainly from investigator-initiated studies, are emerging. These include heavy menstrual bleeding associated with uterine fibroids, endometriosis, adenomyosis, as well as endometrial hyperplasia. In both cohort and randomized studies, the LNG-IUS is effective in decreasing heavy menstrual bleeding, also in women diagnosed with uterine fibroids. In randomized studies the LNG-IUS has shown comparable clinical efficacy to GnRH analogues or progestins for the symptomatic treatment of endometriosis. Experience with LNG-IUS in adenomyosis is based on prospective cohort studies. Dysmenorrhea has been reported to decrease in all women, and uterine volume was seen to diminish in some of these studies. In the treatment of endometrial hyperplasias, including atypical hyperplasia, the LNG-IUS is equal or superior to treatment with systemic progestins. Further studies are needed to examine the full potential of the LNG-IUS in such common clinical situations.

Is abnormal eutopic endometrium the cause of endometriosis? The role of eutopic endometrium in pathogenesis of endometriosis

Endometriosis (EM) is one of the most common diseases which severely affect the health and reproductive function of women of childbearing age. There are fundamental abnormal changes within the eutopic endometrium of women with endometriosis compared to normal endometrium of women without endometriosis. Eutopic endometrium shows enhanced ability of proliferation, implantation and angiogenesis, and greater probability of escaping the unfavorable conditions of the ectopic environment. Therefore, the character of eutopic endometrium determines the fate of the backward-flowing endometrial tissue – to live or to die. The abnormal endometrial tissue in EM patients flows backward to the pelvic cavity, completing a 3-step procedure of pathogenesis (attachment-aggression-angiogenesis), and ultimately develops into EM. Abnormal eutopic endometrium may also play important roles in endometriosis-associated infertility. This recognition regarding the pathogenesis of endometriosis ultimately will help to discover new methods for diagnosis and treatment. Endometrial markers for micro-invasive diagnosis and direct treatment of eutopic endometrium as the origin of the disease should be further investigated.

Changes in glandular and stromal estrogen and progesterone receptor isoform expression in eutopic and ectopic endometrium following treatment with the levonorgestrel-releasing intrauterine system

OBJECTIVES

The levonorgestrel (LNG) intrauterine system (LNG-IUS) has been shown to improve symptoms in women with minimal to moderate endometriosis. The precise mechanism for this is unknown. We hypothesized that this involves alteration in the expression of estrogen receptors (ER) and progesterone receptors (PR).

STUDY DESIGN

A prospective study of tissues obtained prospectively from 28 women with laparoscopically confirmed minimal to moderate endometriosis treated with LNG-IUS for 6 months. Endometrial and endometriotic biopsies obtained before and 6 months after treatment were processed and stained for ER-α, ER-β and PR expression by immunohistochemistry. Photographs were obtained and the receptors quantified.

RESULTS

The mean (±SD) age of the 28 women was 31±7.2 (range 18-42) years. Eight of them at initial biopsy were in the proliferative phase and 20 in the secretory phase. ER-α, ER-β and PR expression decreased significantly in the glandular (P<0.0001) and stromal (P<0.0001) compartments of the eutopic endometrium after treatment with LNG-IUS. Similarly, ER-α, ER-β and PR were significantly decreased in the stromal compartment of ectopic endometrium (P<0.0001), and significantly decreased in the ectopic glands of ER-α (P<0.0001), ER-β (P=0.0002) and PR (P=0.0064) expression.

CONCLUSION

The ameliorative effect of LNG-IUS on the symptoms of minimal to moderate endometriosis is likely modulated through a decrease in the expression of glandular and stromal ER-α, ER-β and PR in the ectopic endometrium.

Aberrant expression of apoptosis-related molecules in endometriosis: a possible mechanism underlying the pathogenesis of endometriosis

Endometriosis, a disease affecting 3% to 10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue under the influence of estrogen. It is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a "death" signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of antiapoptotic factors and decreased expression of preapoptotic factors. Further investigations may elucidate the role of apoptosis-associated molecules in the pathogenesis of endometriosis. Medical treatment with apoptosis-inducing agents may be novel and promising therapeutic strategy for endometriosis.

Hormonal contraceptives and endometriosis/adenomyosis

Over the past 50 years hormonal contraceptives have gradually developed to be cost-effective medical treatment modalities for primary and secondary therapy of endometriosis/adenomyosis. This is particularly true for the various estrogen/progestogen combinations as monophasic - particularly progestogen-dominant - preparations in cyclic, long-cyclic and continuous treatment forms. An alternative is the progestogen-only therapy used continuously. Therapeutic effects have been shown for peritoneal, ovarian and deep-infiltrating endometriosis as well as for adenomyosis. An individualized, medical long-term treatment concept to control endometriosis/adenomyosis-related symptoms, endometriosis/adenomyosis development and minimizing the recurrence rate needs to be further studied in women, who do not desire to become pregnant.

Levonorgestrel-releasing intrauterine system (Mirena) and Depot medroxyprogesterone acetate (Depoprovera) as long-term maintenance therapy for patients with moderate and severe endometriosis: a randomised controlled trial

BACKGROUND

Progestogen therapy has been found to be useful in controlling endometriosis. For patients after conservative surgery, long-term medical maintenance therapy should be sought to prevent recurrence and control symptoms. Levonorgestrel-releasing intrauterine system (LNG-IUS) may be a useful form of prolonged progestogen therapy for endometriosis.

AIMS

To evaluate and compare the efficacy and safety of LNG-IUS to depot medroxyprogesterone acetate (MPA) for patients with moderate or severe endometriosis following conservative surgery, in terms of symptoms control, recurrence prevention and patients' acceptance.

METHODS

A total of 30 patients after conservative surgery for endometriosis underwent randomisation. Of these patients, 15 received LNG-IUS and 15 had three-monthly depot MPA for three years. Their symptom control, recurrence, compliance and change in bone mineral density (BMD) were compared. The data were analysed using student's t-test and chi-square test.

RESULTS

Symptoms and recurrence were controlled by both therapies. The compliance was better in LNG-IUS Group with 13 patients staying on their therapy versus seven patients in Depot MPA Group. LNG-IUS users had a significantly better change in BMD (+0.023, +0.071 g/cm(2)) than Depot MPA users (-0.030, -0.017 g/cm(2)) in both hip and lumbar regions.

CONCLUSIONS

Levonorgestrel-releasing intrauterine system was effective in symptom control and prevention of recurrence. LNG-IUS users showed a better compliance. After three years, bone gain was noted with LNG-IUS, but bone loss with depot MPA.