A comparison of the effect of short-term aromatase inhibitor (letrozole) and GnRH agonist (triptorelin) versus case control on pregnancy rate and symptom and sign recurrence after laparoscopic treatment of endometriosis

A systematic literature review on patient-reported outcome domains and measures in nonsurgical efficacy trials related to chronic pain associated with endometriosis: an urgent call to action

ABSTRACT

Endometriosis, a common cause for chronic pelvic pain, significantly affects quality of life, fertility, and overall productivity of those affected. Therapeutic options remain limited, and collating evidence on treatment efficacy is complicated. One reason could be the heterogeneity of assessed outcomes in nonsurgical clinical trials, impeding meaningful result comparisons. This systematic literature review examines outcome domains and patient-reported outcome measures (PROMs) used in clinical trials. Through comprehensive search of Embase, MEDLINE, and CENTRAL up until July 2022, we screened 1286 records, of which 191 were included in our analyses. Methodological quality (GRADE criteria), information about publication, patient population, and intervention were assessed, and domains as well as PROMs were extracted and analyzed. In accordance with IMMPACT domain framework, the domain pain was assessed in almost all studies (98.4%), followed by adverse events (73.8%). By contrast, assessment of physical functioning (29.8%), improvement and satisfaction (14.1%), and emotional functioning (6.8%) occurred less frequently. Studies of a better methodological quality tended to use more different domains. Nevertheless, combinations of more than 2 domains were rare, failing to comprehensively capture the bio-psycho-social aspects of endometriosis-associated pain. The PROMs used showed an even broader heterogeneity across all studies. Our findings underscore the large heterogeneity of assessed domains and PROMs in clinical pain-related endometriosis trials. This highlights the urgent need for a standardized approach to both, assessed domains and high-quality PROMs ideally realized through development and implementation of a core outcome set, encompassing the most pivotal domains and PROMs for both, stakeholders and patients.

Hormonal Therapies before in vitro fertilization in women with endometriosis: The Minotaur's Labyrinth and the Ariadne's Thread

Endometriosis-related infertility is one of the most debated topics in reproductive medicine. In recent years, prolonged pre-cycle hormonal regimens gained attention as a mean of improving the assisted reproduction technologies (ART) success rates in endometriosis patients. GnRH agonists, dienogest, medroxyprogesterone acetate, and aromatase inhibitors are the most studied medications. Conflicting results and a high risk of bias exist in almost all of the conducted studies in the field. However, current evidence suggests that pre-cycle treatment with GnRH agonists may be beneficial for patients with stage III/IV endometriosis. Dienogest and medroxyprogesterone acetate-based progestin-primed ovarian stimulation protocol was shown to be comparable to the prolonged GnRH agonists protocol. Finally, aromatase inhibitors seem to be of limited benefit to the assisted reproductive outcomes of endometriosis patients. Although it is challenging to draw any clinical conclusions, pre-cycle hormonal treatments seem to be best indicated in endometriosis patients who had previously failed ART treatment.

Beyond the surface: Does stage I-II endometriosis impact fertility? Exploring the challenges of mild disease

Endometriosis is one of the most common gynecologic conditions that women face throughout their lives. Despite advances in technology, diagnosis and treatment of this relapsing and remitting condition is still challenging for many women. This review focuses on literature pertaining to minimal/mild (stage I/II) endometriosis and its impact on fertility. The effectiveness of medical interventions to improve infertility and obstetric outcomes in both natural and assisted reproductive technologies cycles remains debated. The recent ESHRE guidelines suggests that operative laparoscopy could be considered for rASRM stage I/II endometriosis as it improves ongoing pregnancy rates.

Systematic review and meta-analysis on the effect of adjuvant gonadotropin-releasing hormone agonist (GnRH-a) on pregnancy outcomes in women with endometriosis following conservative surgery

BACKGROUND

Endometriosis frequently results in pain and infertility. While conservative surgery offers some relief, it often falls short of ensuring satisfactory pregnancy outcomes. Adjuvant GnRH-a is administered post-surgery to mitigate recurrence; however, its impact on pregnancy outcomes remains debated. This study endeavors to assess the efficacy of adjuvant GnRH-a in enhancing pregnancy outcomes post-conservative surgery in endometriosis patients.

METHODS

Databases including PubMed, Embase, the Cochrane Library, Medline (Ovid), Web of Science, and Scopus were rigorously searched up to 02 August 2023, without linguistic constraints. Identified articles were screened using strict inclusion and exclusion criteria. Evaluated outcomes encompassed pregnancy rate, live birth rate, miscarriage rate, ectopic pregnancy rate, multiple pregnancy rate, mean postoperative pregnancy interval, recurrence rate, and adverse reaction rate. The Cochrane risk of bias tool and the Jadad score evaluated the included studies' quality. Subgroup and sensitivity analysis were implemented to analyze the pooled results. A meta-analysis model expressed results as standardized mean difference (SMD) and Risk ratio (RR).

RESULTS

A total of 17 studies about 2485 patients were assimilated. Meta-analysis revealed that post-surgery, the GnRH-a cohort experienced a marginally elevated pregnancy rate (RR = 1.20, 95% CI = 1.02-1.41; P = 0.03) and a reduced mean time to conceive (RR = -1.17, 95% CI = -1.70- -0.64; P < 0.0001). Contrarily, other evaluated outcomes did not exhibit notable statistical differences.

CONCLUSIONS

Incorporating adjuvant GnRH-a following conservative surgery may be deemed beneficial for women with endometriosis, especially before Assisted Reproductive Technology (ART). Nonetheless, owing to pronounced heterogeneity, subsequent research is warranted to substantiate these potential advantages conclusively.

REGISTRATION NUMBER

CRD42023448280.

A review of phase II and III drugs for the treatment and management of endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease that gives rise to pelvic pain and infertility. Although estroprogestins and progestins currently stand as the first-line treatments for this condition, demonstrating efficacy in two-thirds of patients, a significant portion of individuals experience only partial relief or symptom recurrence following the cessation of these therapies. The coexistence of superficial, deep endometriosis, and ovarian endometriomas, as three distinct phenotypes with unique pathogenetic and molecular characteristics, may elucidate the current heterogeneous biological response to available therapy.

AREAS COVERED

The objective of this review is to furnish the reader with a comprehensive summary pertaining to phase II-III hormonal treatments for endometriosis.

EXPERT OPINION

Ongoing research endeavors are directed toward the development of novel hormonal options for this benign yet debilitating disease. Among them, oral GnRH antagonists emerge as a noteworthy option, furnishing rapid therapeutic onset without an initial flare-up; these drugs facilitate partial or complete estrogen suppression, and promote prompt ovarian function recovery upon discontinuation, effectively surmounting the limitations associated with previously employed GnRH agonists. Limited evidence supports the use of selective estrogen and progesterone receptor modulators. Consequently, further extensive clinical research is imperative to garner a more profound understanding of innovative targets for novel hormonal options.

A Systematic Review of Systematic Reviews on the Use of Aromatase Inhibitors for the Treatment of Endometriosis: The Evidence to Date

Endometriosis is a chronic gynecologic condition that affects around 6-10% of reproductive age women. This clinical entity is characterized with pelvic pain, dysmenorrhea, dyspareunia, and infertility which are the most often presenting symptoms. Aromatase P450 is the key enzyme for ovarian estrogen biosynthesis and there is evidence that endometriotic lesions express aromatase and are able to synthesize their own estrogens. Aromatase inhibitors (AIs) are potent drugs that suppress the estrogen synthesis via suppression of aromatase. We performed a systematic review of systematic reviews and narrative reviews on the use of aromatase inhibitors in the medical management of endometriosis. We searched: PubMed (1950-2022), Google Scholar (2004-2022), Cochrane Library (2010-2022) and Researchgate (2010-2022). The search included the following medical subject headings (MeSH) or keywords: "Aromatase Inhibitors" AND "Endometriosis" AND "Systematic reviews" OR "Systematic review" AND "Reviews" OR "Reviews" AND "Endometriosis". The electronic database search yielded initially 12,106 studies from the different databases. Further assessment of the studies resulted in exclusion of (n = 12,015) studies due to duplicates and irrelevance; Finally, 24 studies were selected for inclusion, 5 were Systematic reviews and 19 were Narrative reviews. The 5 systematic reviews were assessed by AMSTAR-2 criteria and were found to have low quality. Narrative reviews were assessed with SANRA criteria and were found to have high-quality aromatase inhibitors are potent drugs that can manage the endometriosis-related symptoms in cases where initial medical management has failed to show positive results. However, their use is limited by the adverse effects that are linked with menopausal symptoms. aromatase inhibitors can be administered as an alternative treatment in patients. Future studies with randomized design are required to reach safer conclusions and further investigation. These studies should define the therapeutic dose, new add-back therapy modalities. Future directions should examine the most-appropriate way of administration and the duration of therapy.

A Review on the Use of Letrozole in Female and Male Infertility

Infertility in developing countries is a distinct and complex problem that disproportionately affects women. Though not a physically restraining disease, it causes a huge social burden on the emotional, financial, and psychosocial quotients of those who suffer from it. Assisted reproductive procedures are frequently used to treat infertility. Years ago, the emergence of ovulation induction represented a significant advancement in treating female infertility. Letrozole, an aromatase inhibitor, is a potential therapy for ovulation induction. Numerous clinical conditions, including anovulatory infertility, polycystic ovarian syndrome, unexplained infertility, and early stages of endometriosis-related infertility, as well as many with improved live birth rates, have been proven to benefit from letrozole treatment. Letrozole is a superior alternative to the widely utilized ovulation induction with clomiphene citrate. While clomiphene citrate has certain limitations, letrozole successfully overcomes these limitations because of its lack of prolonged anti-estrogenic activity, short half-life, and lack of estrogen receptor activation. In most cases, this results in mono-follicular development and excellent live birth rates. According to the most recent research, letrozole can be used as the first-line therapy to treat infertility caused by polycystic ovarian syndrome and other causes. Letrozole is also emerging as a possible treatment for male infertility of unknown cause, proving to be an effective way of influencing hormonal profiles and increasing various seminal parameters such as sperm motility and concentration, as it inhibits aromatization affecting the feedback mechanism to the hypothalamus. This review focuses on our current knowledge of the uses of letrozole for female and male infertility, its mechanisms, and its benefits.

ESHRE guideline: endometriosis

STUDY QUESTION

How should endometriosis be diagnosed and managed based on the best available evidence from published literature?

SUMMARY ANSWER

The current guideline provides 109 recommendations on diagnosis, treatments for pain and infertility, management of disease recurrence, asymptomatic or extrapelvic disease, endometriosis in adolescents and postmenopausal women, prevention and the association with cancer.

WHAT IS KNOWN ALREADY

Endometriosis is a chronic condition with a plethora of presentations in terms of not only the occurrence of lesions, but also the presence of signs and symptoms. The most important symptoms include pain and infertility.

STUDY DESIGN SIZE DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 1 December 2020 and written in English were included in the literature review.

PARTICIPANTS/MATERIALS SETTING METHODS

Based on the collected evidence, recommendations were formulated and discussed within specialist subgroups and then presented to the core guideline development group (GDG) until consensus was reached. A stakeholder review was organized after finalization of the draft. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

This guideline aims to help clinicians to apply best care for women with endometriosis. Although studies mostly focus on women of reproductive age, the guideline also addresses endometriosis in adolescents and postmenopausal women. The guideline outlines the diagnostic process for endometriosis, which challenges laparoscopy and histology as gold standard diagnostic tests. The options for treatment of endometriosis-associated pain symptoms include analgesics, medical treatments and surgery. Non-pharmacological treatments are also discussed. For management of endometriosis-associated infertility, surgical treatment and/or medically assisted reproduction are feasible. While most of the more recent studies confirm previous ESHRE recommendations, there are five topics in which significant changes to recommendations were required and changes in clinical practice are to be expected.

LIMITATIONS REASONS FOR CAUTION

The guideline describes different management options but, based on existing evidence, no firm recommendations could be formulated on the most appropriate treatments. Also, for specific clinical issues, such as asymptomatic endometriosis or extrapelvic endometriosis, the evidence is too scarce to make evidence-based recommendations.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in endometriosis care, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in endometriosis.

STUDY FUNDING/COMPETING INTERESTS

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payments. C.M.B. reports grants from Bayer Healthcare and the European Commission; Participation on a Data Safety Monitoring Board or Advisory Board with ObsEva (Data Safety Monitoring Group) and Myovant (Scientific Advisory Group). A.B. reports grants from FEMaLE executive board member and European Commission Horizon 2020 grant; consulting fees from Ethicon Endo Surgery, Medtronic; honoraria for lectures from Ethicon; and support for meeting attendance from Gedeon Richter; A.H. reports grants from MRC, NIHR, CSO, Roche Diagnostics, Astra Zeneca, Ferring; Consulting fees from Roche Diagnostics, Nordic Pharma, Chugai and Benevolent Al Bio Limited all paid to the institution; a pending patent on Serum endometriosis biomarker; he is also Chair of TSC for STOP-OHSS and CERM trials. O.H. reports consulting fees and speaker's fees from Gedeon Richter and Bayer AG; support for attending meetings from Gedeon-Richter, and leadership roles at the Finnish Society for Obstetrics and Gynecology and the Nordic federation of the societies of obstetrics and gynecology. L.K. reports consulting fees from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; honoraria for lectures from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; support for attending meetings from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; he also has a leadership role in the German Society of Gynecological Endocrinology (DGGEF). M.K. reports grants from French Foundation for Medical Research (FRM), Australian Ministry of Health, Medical Research Future Fund and French National Cancer Institute; support for meeting attendance from European Society for Gynaecological Endoscopy (ESGE), European Congress on Endometriosis (EEC) and ESHRE; She is an advisory Board Member, FEMaLe Project (Finding Endometriosis Using Machine Learning), Scientific Committee Chair for the French Foundation for Research on Endometriosis and Scientific Committee Chair for the ComPaRe-Endometriosis cohort. A.N. reports grants from Merck SA and Ferring; speaker fees from Merck SA and Ferring; support for meeting attendance from Merck SA; Participation on a Data Safety Monitoring Board or Advisory Board with Nordic Pharma and Merck SA; she also is a board member of medical advisory board, Endometriosis Society, the Netherlands (patients advocacy group) and an executive board member of the World Endometriosis Society. E.S. reports grants from National Institute for Health Research UK, Rosetrees Trust, Barts and the London Charity; Royalties from De Gruyter (book editor); consulting fees from Hologic; speakers fees from Hologic, Johnson & Johnson, Medtronic, Intuitive, Olympus and Karl Storz; Participation in the Medicines for Women's Health Expert Advisory Group with Medicines and Healthcare Products Regulatory Agency (MHRA); he is also Ambassador for the World Endometriosis Society. C.T. reports grants from Merck SA; Consulting fees from Gedeon Richter, Nordic Pharma and Merck SA; speaker fees from Merck SA, all paid to the institution; and support for meeting attendance from Ferring, Gedeon Richter and Merck SA. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (Full disclaimer available at www.eshre.eu/guidelines.).

The efficacy and safety of triptorelin-therapy following conservative surgery for deep infiltrating endometriosis: A multicenter, prospective, non-interventional study in China

Triptorelin is one of the most commonly used gonadotropin-releasing hormone agonists and has been used in the treatment of deep infiltrating endometriosis (DIE). This study aimed to evaluate the efficacy and safety of up to 24 weeks of triptorelin treatment after conservative surgery for DIE.This prospective, non-interventional study was performed in 18 tertiary hospitals in China. Premenopausal women aged ≥18 years treated with triptorelin 3.75 mg once every 28 days for up to 24 weeks after conservative surgery for DIE were included. Endometriosis symptoms were assessed, using a visual analogue scale (0-10 cm) or numerical range (0-10), at baseline (pre-surgery) and routine visits 3, 6, 9, 12, 18, and 24 months after surgery. Changes in symptom intensity over time were primary outcome measures.A total of 384 women (mean [standard deviation] age, 33.4 [6.2] years) were analyzed. Scores for all symptoms (pelvic pain, dysmenorrhea, ovulation pain, dyspareunia, menorrhagia, metrorrhagia, and gastrointestinal and urinary symptoms) assessed decreased from baseline over 24 months. Cumulative improvement rates in pelvic pain, dysmenorrhoa, ovulation pain, and dyspareunia were 74.4%, 83.6%, 55.1%, and 66.9%, respectively. The 24-month cumulative recurrence rate (≥1 symptom) was 22.2%. The risk of symptom recurrence was higher in patients with ≥2 versus 1 lesion (odds ratio [OR] 2.539; 95% CI: 1.458-4.423; P = .001) and patients with moderate (OR 5.733; 95% CI: 1.623-20.248; P = .007) or severe (OR 8.259; 95% CI: 2.449-27.851; P = .001) pain versus none/mild pain. Triptorelin was well tolerated without serious adverse events.Triptorelin after conservative surgery for DIE improved symptoms over 24 months of follow up. The recurrence rate of symptoms was low and triptorelin was generally well tolerated.Trial registration number: ClinicalTrials.gov, NCT01942369.

Is intracrinology of endometriosis relevant in clinical practice? A systematic review on estrogen metabolism

Endometriosis is a chronic, multifactorial, estrogen-dependent disease. The abnormal endocrine microenvironment of endometriosis lesions is considered a main feature and multiple enzymatic pathways leading to local increased synthesis of estrogens have been identified. However, the relevance of intracrinology in clinical practice is still lacking. Medline, Embase, Scopus database were systematically searched for studies reporting on local estrogens metabolism of endometriotic lesions. The main enzymatic pathways involved in the intracrinology of endometriosis such as aromatase (CYP19A1), 17β-hydroxysteroid dehydrogenase (HSD17B) type 1, type 2 and type 5, steroid sulfatase (STS), estrogen sulfotransferase (SULT1E1) were assessed with a critical perspective on their role in disease endocrine phenotyping, drug resistance and as therapeutic targets. Overall, studies heterogeneity and missing clinical data affect the interpretation of the clinical role of these enzymes. Although the use of some drugs such as aromatase inhibitors has been proposed in clinical practice for two decades, their potential clinical value is still under investigation as well as their modality of administration. A closer look at new, more realistic drug targets is provided and discussed. Altered expression of these key enzymes in the lesions have far reaching implication in the development of new drugs aimed at decreasing local estrogenic activity with a minimal effect on gonadal function; however, given the complexity of the evaluation of the expression of the enzymes, multiple aspects still remains to be clarified.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022311329, identifier CRD42022311329.

Ovulation induction with clomiphene citrate or letrozole following laparoscopy in infertile women with minimal to mild endometriosis: a prospective randomised controlled trial

We conducted a prospective randomised controlled trial to explore the efficacy of clomiphene citrate (CC) and Letrozole (LTZ) for improving fecundity in infertile women with minimal to mild endometriosis after operative laparoscopy. We found that the ovulation rate of LTZ (88.7%) and CC (84.5%) were significantly higher than that of Control (70.5%) (p < .001). However, there was no significant difference in cumulative clinical pregnancy rates at 3, 6, 12 months after laparoscopy among the three groups (LTZ: 30%, 34.3%, 38.6% vs CC: 28.6%, 42.9%, 50.0% vs Control: 18.6%, 24.3%, 31.4%, respectively). No significant difference was observed in live-birth rate among the three groups (p = 1.125). For infertile women with minimal to mild endometriosis, ovulation induction with letrozole or clomiphene citrate after laparoscopy significantly increases ovulation rate, which are comparable between them; but does not demonstrate a significant advantage on improving pregnancy rate and live-birth rate when compared to laparoscopy alone.Impact statementWhat is already known on this subject? Endometriosis significantly decreases fecundity of women. Operative laparoscopy was recommended as an effective option to increase spontaneous pregnancy rate in infertile women with minimal to mild endometriosis. However, there is still no optimum treatment strategy for improving fertility of women with endometriosis.What do the results of this study add? For infertile women with minimal to mild endometriosis, ovulation induction with letrozole or clomiphene citrate after laparoscopy significantly increases ovulation rate, which are comparable between them; but does not demonstrate a significant advantage on improving pregnancy rate and live-birth rate when compared to laparoscopy alone.What are the implications of these findings for clinical practice and/or further research? Our results suggest that operative laparoscopy in conjunction with ovulation induction may improve fertility of women with minimal to mild endometriosis. Further research could focus on prolonging cycles of ovulation induction or choosing alternative ovarian stimulation protocols. More RCTs are still needed to compare the efficacy of letrozole with CC in ovulation induction.

Mesenchymal Stem Cells in Preclinical Infertility Cytotherapy: A Retrospective Review

Infertility is a global reproductive disorder which is caused by a variety of complex diseases. Infertility affects the individual, family, and community through physical, psychological, social and economic consequences. The results from recent preclinical studies regarding stem cell-based therapies are promising. Stem cell-based therapies cast a new hope for infertility treatment as a replacement or regeneration strategy. The main features and application prospects of mesenchymal stem cells in the future of infertility should be understood by clinicians. Mesenchymal stem cells (MSCs) are multipotent stem cells with abundant source, active proliferation, and multidirectional differentiation potential. MSCs play a role through cell homing, secretion of active factors, and participation in immune regulation. Another advantage is that, compared with embryonic stem cells, there are fewer ethical factors involved in the application of MSCs. However, a number of questions remain to be answered prior to safe and effective clinical application. In this review, we summarized the recent status of MSCs in the application of the diseases related to or may cause to infertility and suggest a possible direction for future cytotherapy to infertility.

Novel therapeutic targets to improve IVF outcomes in endometriosis patients: a review and future prospects

BACKGROUND

Patients with endometriosis often experience infertility and have poor IVF outcomes, with low fertilization and pregnancy rates. Although many theories have tried to explain the mechanisms underlying infertility in these patients, none of them is conclusive.

OBJECTIVE AND RATIONALE

In this review, we discuss the pathologic mechanisms through which endometriosis likely leads to infertility along with the therapeutic options used to date to treat endometriosis-related infertility and, thereby, to improve IVF outcomes in patients with endometriosis.

SEARCH METHODS

We performed a comprehensive literature search of clinical outcomes in endometriosis and the molecular mechanisms contributing to oocyte quality using the PubMed database to identify human and animal studies published from 1992 until September 2020. In total, 123 manuscripts were included.

OUTCOMES

While some theories propose that endometriosis patients may have fertility problems as a result of decreased endometrial receptivity, others reinforce the idea that infertility could be associated with oocyte alterations and lower implantation rates. Single-cell RNA sequencing of oocytes from patients with endometriosis has identified dysregulated mechanisms involved in steroid metabolism and biosynthesis, response to oxidative stress and cell cycle regulation. Dysregulation of these mechanisms could result in the poor IVF outcomes observed in patients with endometriosis. Further, impaired steroidogenesis may directly affect oocyte and embryo quality. Increased oxidative stress in patients with endometriosis also has a detrimental effect on the follicular microenvironment, inducing cell cycle dysregulation in oocytes, poor oocyte quality, and infertility. Moreover, granulosa cells in the context of endometriosis undergo increased apoptosis and have an altered cell cycle that could adversely affect folliculogenesis, oocyte and embryo quality, and IVF outcomes. Endometriosis is also associated with inflammatory damage and impaired angiogenesis, which could be directly correlated with poor IVF outcomes. While therapeutic options using GnRH analogues, progestins and aromatase inhibitors do not improve endometriosis-related infertility, anti-inflammatory agents and antioxidant supplementation could improve oocyte quality as well as implantation and clinical pregnancy rates in patients with endometriosis.

WIDER IMPLICATIONS

Endometriosis is a heterogeneous disease whose pathogenesis is complex and could affect fertility by altering a collection of molecular mechanisms in oocytes. Thus, a single model is not sufficient to describe endometriosis-related infertility. Dysregulation of steroidogenesis, oxidative stress, cell cycle progression, inflammation and angiogenesis in the follicular environment and oocytes in individuals with endometriosis are all possible contributors to endometriosis-related infertility. Therefore, treatments targeting these mechanisms could be therapeutic alternatives to improve IVF outcomes for these patients.

Letrozole for Female Infertility

Letrozole, an aromatase inhibitor that blocks estrogen synthesis by inhibiting the final step of the estrogen biosynthetic pathway, has been used in the applications of a wide range of infertility settings. It has been more than 20 years since the initial clinical trial of letrozole for ovulation induction. In light of the accumulating clinical and basic evidence, the efficacy and safety of letrozole have been identified. This mini review focuses on our current knowledge of the applications and mechanisms of letrozole for female infertility and various questions are put forward about how letrozole could be more effectively used.

Aromatase inhibitors for the treatment of endometriosis: a systematic review about efficacy, safety and early clinical development

INTRODUCTION

Pharmacotherapy has a key role in endometriosis treatment and management, however, a significant proportion of patients have only intermittent or limited benefits with current treatment options. Therefore, novel therapeutic approaches are necessary.

AREAS COVERED

This systematic review provides an overview of the efficacy and safety of aromatase inhibitors (AIs) as monotherapies and combination therapies for endometriosis. A systematic literature search was performed from January 1990 to April 2020 in the electronic database MEDLINE, EMBASE, The Cochrane Library, and Web of Science.

EXPERT OPINION

Based on the critical role of estrogens and the rate-limiting step in the production of the estrogens represented by the aromatase enzyme, AIs are a potential therapeutic option for women affected by endometriosis. Nevertheless, further research is needed to clarify the efficacy of AIs in this setting. Adverse effects need to be investigated to clarify the preventive role of add-back therapy. On that basis, AIs should be adopted only as second-line therapy in patients who are refractory to standard treatments in the setting of scientific research. Further studies should define best dosages, appropriate add-back therapies, administration routes, treatment length, and which patients may benefit more from AIs.

Effects of omega-6/3 and omega-9/6 nutraceuticals on pain and fertility in peritoneal endometriosis in rats

Purpose:

To evaluate the effects of the nutraceuticals omega-6/3 and omega-9/6 on endometriosis-associated infertility and pain.

Methods:

Controlled experimental study, with each group composed of eight female rats. Fertility groups: sham-operated control (0.9% saline solution); control with endometriosis (0.9% saline); omega-6/3 (1.2 g/kg/day); omega-9/6 (1.2 g/kg/day); and meloxicam (0.8 mg/kg/day). Pain groups: sham-operated control (0.9% saline); control with endometriosis (0.9% saline); omega-6/3 (1.2 g/kg/day); omega-9/6 (1.2 g/kg/day); medroxyprogesterone acetate (5 mg/kg/every 3 days); and meloxicam (0.8 mg/kg/day). Peritoneal endometriosis was surgically induced. Pain was evaluated with the writhing test. Fertility was evaluated by counting the number of embryos in the left hemi-uterus.

Results:

The mean number of writhings was as follows: sham-operated, 11.1 ± 2.9; control with endometriosis, 49.3 ± 4.4; omega-6/3, 31.5 ± 2.7; omega-9/6, 34.1 ± 4.5; medroxyprogesterone acetate, 2.1 ± 0.8; meloxicam, 1 ± 0.3. There was a significant difference between both controls and all drugs used for treatment. Regarding fertility, the mean values were as follows: sham-operated, 6.8 ± 0.6; control with endometriosis, 4.2 ± 0.7; omega-6/3, 4.7 ± 1; omega-9/6, 3.8 ± 0.9; and meloxicam, 1.8 ± 0.9.

Conclusions:

The omega-6/3 and omega-9/6 nutraceuticals decreased pain compared to the controls. There was no improvement in fertility in any of the tested groups.

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.

[New medical treatments for painful endometriosis: CNGOF-HAS Endometriosis Guidelines]

OBJECTIVE

The objective of this work is to evaluate the place of new treatments in the management of endometriosis outside the context of infertility.

METHODS

A review of the literature was conducted by consulting Medline data until July 2017.

RESULTS

Dienogest is effective compared to placebo in short term (NP2) and long term (NP4) for the treatment of painful endometriosis. In comparison with GnRH agonists, dienogest is also effective in terms of decreased pain and improved quality of life in non-operated patients (NP2) as well as for recurrence of lesions and symptomatology postoperatively (NP2). Data on GnRH antagonists, selective progesterone receptor modulators as well as selective inhibitors (anti-TNF-α, matrix metalloprotease inhibitors, angiogenesis growth factor inhibitors) are insufficient to provide evidence of interest in clinical practice for the management of painful endometriosis (NP3).

CONCLUSION

Dienogest is recommended as second-line therapy for the management of painful endometriosis (Grade B). Because of lack of evidence, aromatase inhibitors, elagolix, SERM, SPRM and anti-TNF-α are not recommended for the management of painful endometriosis (Grade C).

[Medical treatment of endometriosis: Hormonal treatment of pain, impact on evolution and future perspectives]

CONTEXT

Endometriosis is a chronic painful disease, for which hormone therapy is usually offered as a first line option to women not willing to conceive.

OBJECTIVES

To analyse and synthesize the literature, from 2006 onwards, on pain control, and disease evolution in oemn using combined hormonal contraceptives, progestins and GnRH analogs. Data on other current and future treatment perspectives is included as well.

SOURCES

Medline (Pubmed), the Cochrane Library, and endometriosis treatment recommendations published by European Society of Human Reproduction and Embryology (ESHRE), National Institute for health and Care Excellence (NICE), American College of Obstetricians and Gynecologists (ACOG), Royal College of Obstetricians and Gynaecologists (RCOG) and Société des Obstétriciens et Gynécologues du Canada (SOGC).

STUDY SELECTION

Meta-analysis and clinical trials are included.

RESULTS

Study quality is heterogeneous in general. Hormone therapy inconstantly allows pain relief and prevention of endometrioma and rectovaginal wall nodules recurrence. Available molecules and routes of administration as well as risk benefit balance are evaluated. Data on future perspectives are limited to date and do not allow use in routine.

CONCLUSION

Hormonal treatment of endometriosis relies on combined hormonal contraceptives (using different routes of administration), progestins and particularly the levonorgestrel-releasing IUS, and GnRH analogs as a last option, in combination with an add-back therapy. Promising alternatives are currently under preclinical and clinical evaluation.

"Per vaginam" topical use of hormonal drugs in women with symptomatic deep endometriosis: a narrative literature review

PURPOSE

We aim to provide a comprehensive overview of the role of the vagina as a route for drug delivery and absorption, with a particular focus on the use of vaginal hormonal compounds for the treatment of deep infiltrating symptomatic endometriosis.

METHODS

A MEDLINE search through PubMed was performed to identify all published studies in English language on vaginal hormonal treatments for symptomatic endometriosis.

RESULTS

Main advantages of the vaginal route include avoidance of the hepatic-first pass metabolic effect, the possibility of using lower therapeutic dosages, and the reduction of side effects compared with the oral administration. Studies on endometriosis treatment mainly focused on the use of vaginal danazol (n = 6) and the contraceptive vaginal ring (n = 2). One pilot study evaluated the efficacy of vaginal anastrozole in women with rectovaginal endometriosis. Most investigations evaluated the vaginal use of hormonal agents in women with deep infiltrating endometriosis/rectovaginal endometriosis. Overall, a substantial amelioration of pelvic pain symptoms associated with endometriosis was observed, particularly of dysmenorrhea. A significant reduction in rectovaginal endometriotic nodule dimensions measured at ultrasound examination was detected by some but not all authors.

CONCLUSIONS

The vaginal route represents a scarcely explored modality for drug administration. High local hormonal concentrations might achieve a greater effect on endometriotic lesions compared with alternative routes. Future studies should focus on the use of the vagina for delivering target therapies particularly in patients with deeply infiltrating rectovaginal lesions.

Aromatase Inhibitors for Endometriosis-Associated Infertility; Do We Have Sufficient Evidence?

Orally active aromatase inhibitors (AIs) have gained attention for treatment of infertile women with endometriosis in whom aromatase p450 is aberrantly expressed. This review aimed to critically appraise and summarize the available evidence concerning the use of AIs for management of endometriosis-associated infertility. PubMed was searched to May 2015 with the following key words: endometriosis, infertility and aromatase. Priority was given for randomized controlled trials (RCTs) followed by other study designs. Main outcome measures were as follows: rates of clinical pregnancy, miscarriage and live birth as well as endocrine outcomes. Eighty-two abstracts were screened and six original articles were included. A RCT demonstrated that post-operative letrozole treatment did not improve spontaneous pregnancy rate. Another RCT reported no superiority of letrozole superovulation over clomiphene citrate (each combined with intrauterine insemination) in minimalmild endometriosis and previous laparoscopic treatment. Anastrozole significantly inhibited the growth of endometriotic cells and their estrogen production in culture. In assisted reproductive technology (ART) cycles, dual suppression (Agonist/anastrozole) was tested in a pilot study with a pregnancy rate of 45% however, high pregnancy loss (30%) occurred. A retrospective study showed that letrozole may improve endometrial receptivity in endometriotic patients undergoing in vitro fertilization (IVF). An opposite view from an in vitro study showed lower estradiol production and aromatase expression in cultured granulosa cells from endometriotic women undergoing IVF and marked reduction under letrozole. In conclusion, current evidence is limited. More trials are warranted to enhance our knowledge and provide a clear and unequivocal evidence to guide our clinical management of infertile women with endometriosis using AIs.

A prospective cohort study of endometriosis and subsequent risk of infertility

STUDY QUESTION

Is there a temporal relationship between endometriosis and infertility?

SUMMARY ANSWER

Endometriosis is associated with a higher risk of subsequent infertility, but only among women age <35 years.

WHAT IS KNOWN ALREADY

Endometriosis is the most commonly observed gynecologic pathology among infertile women undergoing laparoscopic examination. Whether endometriosis is a cause of infertility or an incidental discovery during the infertility examination is unknown.

STUDY DESIGN, SIZE, DURATION

This study included data collected from 58 427 married premenopausal female nurses <40 years of age from 1989 to 2005, who are participants of the Nurses' Health Study II prospective cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our exposure was laparoscopically confirmed endometriosis. Multivariate Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for infertility risk (defined as attempting to conceive for >12 months) among women with and without endometriosis.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified 4612 incident cases of infertility due to any cause over 362 219 person-years of follow-up. Compared with women without a history of endometriosis, women with endometriosis had an age-adjusted 2-fold increased risk of incident infertility (HR = 2.12, 95% CI = 1.76-2.56) that attenuated slightly after accounting for parity. The relationship with endometriosis was only observed among women <35 years of age (multivariate HR <35 years = 1.77, 95% CI = 1.46-2.14; multivariate HR 35-39 years = 1.20, 95% CI = 0.94-1.53; P-interaction = 0.008). Risk of primary versus secondary infertility was similar subsequent to endometriosis diagnosis. Among women with primary infertility, 50% became parous after the endometriosis diagnosis, and among all women with endometriosis, 83% were parous by age 40 years.

LIMITATIONS, REASONS FOR CAUTION

We did not have information on participants' intentions to conceive, but by restricting the analytic population to married women we increased the likelihood that pregnancies were planned (and therefore infertility would be recognized). Women in our cohort with undiagnosed asymptomatic endometriosis will be misclassified as unexposed. However, the small proportion of these women are diluted among the >50 000 women accurately classified as endometriosis-free, minimizing the impact of exposure misclassification on the effect estimates.

WIDER IMPLICATIONS OF THE FINDINGS

This study supports a temporal association between endometriosis and infertility risk. Our prospective analysis indicates a possible detection bias in previous studies, with our findings suggesting that the infertility risk posed by endometriosis is about half the estimates observed in cross-sectional analyses.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Institutes of Health (grant numbers: UM1 CA176726, HD52473, HD57210, T32DK007703, T32HD060454, K01DK103720). We have no competing interests to declare.

Variation in outcome reporting in endometriosis trials: a systematic review

OBJECTIVE

We reviewed the outcomes and outcome measures reported in randomized controlled trials and their relationship with methodological quality, year of publication, commercial funding, and journal impact factor.

DATA SOURCES

We searched the following sources: (1) Cochrane Central Register of Controlled Trials, (2) Embase, and (3) MEDLINE from inception to November 2014.

STUDY ELIGIBILITY

We included all randomized controlled trials evaluating a surgical intervention with or without a medical adjuvant therapy for the treatment of endometriosis symptoms.

STUDY DESIGN

Two authors independently selected trials, assessed methodological quality (Jadad score; range, 1-5), outcome reporting quality (Management of Otitis Media with Effusion in Cleft Palate criteria; range, 1-6), year of publication, impact factor in the year of publication, and commercial funding (yes or no). Univariate and bivariate analyses were performed using Spearman Rh and Mann-Whitney U tests. We used a multivariate linear regression model to assess relationship associations between outcome reporting quality and other variables.

RESULTS

There were 54 randomized controlled trials (5427 participants), which reported 164 outcomes and 113 outcome measures. The 3 most commonly reported primary outcomes were dysmenorrhea (10 outcome measures; 23 trials), dyspareunia (11 outcome measures; 21 trials), and pregnancy (3 outcome measures; 26 trials). The median quality of outcome reporting was 3 (interquartile range 4-2) and methodological quality 3 (interquartile range 5-2). Multivariate linear regression demonstrated a relationship between outcome reporting quality with methodological quality (β = 0.325; P = .038) and year of publication (β = 0.067; P = .040). No relationship was demonstrated between outcome reporting quality with journal impact factor (Rho = 0.190; P = .212) or commercial funding (P = .370).

CONCLUSION

Variation in outcome reporting within published endometriosis trials prohibits comparison, combination, and synthesis of data. This limits the usefulness of research to inform clinical practice, enhance patient care, and improve patient outcomes. In the absence of a core outcome set for endometriosis we recommend the use of the 3 most common pain (dysmenorrhea, dyspareunia, and pelvic pain) and subfertility (pregnancy, miscarriage, and live birth) outcomes. International consensus among stakeholders is needed to establish a core outcome set for endometriosis trials.

Aromatase inhibitors in the treatment of endometriosis

Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by 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.

Endometriosis: alternative methods of medical treatment

Endometriosis is an inflammatory estrogen-dependent disease defined by the presence of endometrial glands and stroma at extrauterine sites. The main purpose of endometriosis management is alleviating pain associated to the disease. This can be achieved surgically or medically, although in most women a combination of both treatments is required. Long-term medical treatment is usually needed in most women. Unfortunately, in most cases, pain symptoms recur between 6 months and 12 months once treatment is stopped. The authors conducted a literature search for English original articles, related to new medical treatments of endometriosis in humans, including articles published in PubMed, Medline, and the Cochrane Library. Keywords included "endometriosis" matched with "medical treatment", "new treatment", "GnRH antagonists", "Aromatase inhibitors", "selective progesterone receptor modulators", "anti-TNF α", and "anti-angiogenic factors". Hormonal treatments currently available are effective in the relief of pain associated to endometriosis. Among new hormonal drugs, association to aromatase inhibitors could be effective in the treatment of women who do not respond to conventional therapies. GnRH antagonists are expected to be as effective as GnRH agonists, but with easier administration (oral). There is a need to find effective treatments that do not block the ovarian function. For this purpose, antiangiogenic factors could be important components of endometriosis therapy in the future. Upcoming researches and controlled clinical trials should focus on these drugs.

National German Guideline (S2k): Guideline for the Diagnosis and Treatment of Endometriosis: Long Version - AWMF Registry No. 015-045

In this guideline, recommendations and standards for optimum diagnosis and treatment of endometriosis are presented. They are based on the analysis of the available scientific evidence as published in prospective randomized and retrospective studies as well as in systematic reviews. The guideline working group consisted of experts from Austria, Germany, Switzerland, and the Czech Republic.

Triptorelin for the treatment of endometriosis

INTRODUCTION

Over the past 30 years, gonadotropin-releasing hormone agonists (GnRH-a) have been used to induce a hypoestrogenic status in women with endometriosis with the aim to cause an improvement in pain symptoms similar to that observed after menopause. Triptorelin is one of the most commonly used GnRH-a.

AREAS COVERED

This review offers an explanation of the mechanism of action, of the pharmacokinetics and pharmacodynamics of triptorelin and gives the readers a complete overview of the studies on the clinical efficacy, tolerability and safety of this agent in patients with endometriosis.

EXPERT OPINION

The studies reviewed in the current manuscript demonstrate the efficacy of triptorelin in improving pain symptoms caused by endometriosis. Further, this effect is confirmed by the reduction in the volume of the endometriotic nodules during treatment. Future research should evaluate whether the pre-operative administration of triptorelin prior to surgical excision of endometriomas may be useful in preserving the ovarian reserve.

Systematic review of endometriosis pain assessment: how to choose a scale?

BACKGROUND

Numerous studies concerning endometriosis and pain have been reported. However, there is no consensus on the best method to evaluate pain in endometriosis and many scales have been used. Moreover, there are only a few descriptions of minimal clinically important differences after treatment (MCID) to evaluate variations in pain. In our study, we aim to identify pain scales used in endometriosis pain treatment, to address their strong and weak points and to define which would be the ideal scale to help clinicians and researchers to evaluate endometriosis-related pain.

METHODS

A search of the MEDLINE and EMBASE databases was carried out for publications in English, French or Portuguese from 1980 to December 2012, for the words: endometriosis, treatment, pain. Studies were selected if they studied an endometriosis treatment and a pain scale was specified. A quantitative and a qualitative analysis of each scale was performed to define strong and weak points of each scale (systematic registration number: CRD42013005336).

RESULTS

A total of 736 publications were identified. After excluding duplications and applying inclusion criteria 258 studies remained. We found that the visual analog scale (VAS) is the most frequently used scale. Both VAS and the numerical rating scale (NRS) show a good balance between strong and weak points in comparison with others such as the Biberoglu and Behrman scale. Concerning MCID, only VAS, NRS and Brief Pain Inventory scales have reported MCID and, among these, only VAS MCID has been studied in endometriosis patients (VAS MCID = 10 mm). Adding the Clinical Global Impression score (CGI) to the pain scale allows calculation of the MCID.

CONCLUSIONS

When using pain scales their strengths and weaknesses must be known and included in the analysis. VAS is the most frequently used pain scale and, together with NRS, seems the best adapted for endometriosis pain measurement. The use of VAS or NRS for each type of typical pain related to endometriosis (dysmenorrhea, deep dyspareunia and non-menstrual chronic pelvic pain), combined with the CGI and a quality-of-life scale will provide both clinicians and researchers with tools to evaluate treatment response.

Potential role of aromatase inhibitors in the treatment of endometriosis

Endometriosis is an estrogen-dependent chronic inflammatory disease affecting 5%–10% of reproductive-age women, with a prevalence of 5%–50% in infertile women and >33% of women with chronic pelvic pain. Third-generation aromatase inhibitors (AIs) are approved adjuvants for the treatment of estrogen receptor-positive breast cancer. Molecular studies have revealed the presence of aromatase P450, the key enzyme in the biosynthesis of ovarian estradiol, inside the endometriotic tissue, indicating local synthesis of estradiol. Thereby, AIs represent an appealing medical option for the management of different aspects of this enigmatic disease, especially pelvic pain and infertility. Accordingly, this review aims to evaluate the potential role of AIs in the treatment of endometriosis-associated symptoms, mainly pain and infertility. Notably, several studies have demonstrated that the combination of AIs with conventional therapy as oral contraceptive pills, progestins, or gonadotropin-releasing hormone analogs can be used to control endometriosis-associated pain and pain recurrence in premenopausal women, particularly those with pain due to rectovaginal endometriosis refractory to other medical or surgical treatment. Some case reports have shown promising results in the treatment of postmenopausal endometriosis as first-line treatment, when surgery is contraindicated, or as second-line treatment in the case of postoperative recurrence. Third-generation AIs, especially letrozole, have challenged clomiphene citrate as an ovulation-induction agent in patients with polycystic ovary syndrome and in cases of unexplained infertility. However, few studies are available regarding the use of AIs to treat endometriosis-associated infertility. Therefore, larger multicenter randomized trials using AIs for the treatment of endometriosis-associated infertility are needed to clarify its effect. The safety of AIs for ovulation induction or superovulation has generated a lively discussion. Data from recent retrospective and prospective studies have supported its safety.

Endometriosis: pathogenesis and treatment

Endometriosis is defined as the presence of endometrial-type mucosa outside the uterine cavity. Of the proposed pathogenic theories (retrograde menstruation, coelomic metaplasia and Müllerian remnants), none explain all the different types of endometriosis. According to the most convincing model, the retrograde menstruation hypothesis, endometrial fragments reaching the pelvis via transtubal retrograde flow, implant onto the peritoneum and abdominal organs, proliferate and cause chronic inflammation with formation of adhesions. The number and amount of menstrual flows together with genetic and environmental factors determines the degree of phenotypic expression of the disease. Endometriosis is estrogen-dependent, manifests during reproductive years and is associated with pain and infertility. Dysmenorrhoea, deep dyspareunia, dyschezia and dysuria are the most frequently reported symptoms. Standard diagnosis is carried out by direct visualization and histologic examination of lesions. Pain can be treated by excising peritoneal implants, deep nodules and ovarian cysts, or inducing lesion suppression by abolishing ovulation and menstruation through hormonal manipulation with progestins, oral contraceptives and gonadotropin-releasing hormone agonists. Medical therapy is symptomatic, not cytoreductive; surgery is associated with high recurrence rates. Although lesion eradication is considered a fertility-enhancing procedure, the benefit on reproductive performance is moderate. Assisted reproductive technologies constitute a valid alternative. Endometriosis is associated with a 50% increase in the risk of epithelial ovarian cancer, but preventive interventions are feasible.

The Place of Gonadotropin-Releasing Hormone Agonists in the Management of Endometriosis

Purpose

This review focuses on the use of the gonadotropin-releasing hormone (GnRH) agonists, a typically marginalized class of drugs, and describes their role in the management of endometriosis, with special interest in 4 regions: Western Europe, Eastern Europe, the Middle East and China.

Methods

The authors met in Dubai in November 2012 for a consensus meeting on the use of GnRH agonists in the 4 regions. The meeting was based on a review of the published regional guidelines for endometriosis and a selective literature search of articles published in the past 5 years that focused on the use of GnRH agonists in endometriosis.

Results

The guidelines place GnRH agonists as a second-line option for the management of pain in deep infiltrating endometriosis and to improve fertility in women planning to undergo in vitro fertilization. Published articles and personal evidence presented at the meeting suggest that surgery for endometriomas should be delayed as long as possible to conserve ovarian function and that GnRH agonist therapy after surgery may reduce their recurrence. However, although add-back therapy is advocated with the use of GnRH agonists, there is no consensus on when this should be started.

Conclusions

There are important regional differences in cultural sensitivities to diagnosis and treatment of endometriosis, as well as a diverging approach to surgery. Given the limitations and conflicts in the diagnosis and management of endometriosis, it is essential that the available drugs, including the GnRH agonists, are used in the most appropriate settings.

An update on the pharmacological management of endometriosis

INTRODUCTION

Endometriosis is a common disease that causes pain symptoms and/or infertility in women in their reproductive years. The disease is characterised by the presence of endometrium-like tissue - glands and stroma - outside the uterine cavity. Different treatment options exist for endometriosis including medical and surgical treatments or a combination of the two approaches. The most commonly used medications are non-steroidal anti-inflammatory drugs, GnRH agonists, androgen derivatives such as danazol, combined oral contraceptive pills, progestogens and more recently the levonorgestrel intrauterine system.

AREAS COVERED

The authors review current medical treatments used for symptomatic endometriosis and also discuss new treatment approaches. The authors conducted a literature search for randomised controlled trials related to medical treatments of endometriosis in humans, searched the Cochrane library for reviews and also searched for registered trials that have not yet been published on ClinicalTrials.gov.

EXPERT OPINION

The medical treatment of endometriosis is effective at treating pain and preventing recurrence of disease after surgery. Remarkably, the oral contraceptive pill taken continuously is as effective as GnRH-a, while causing far less side-effects. Conversely, no treatment currently exists for enhancing fecundity in women whose infertility is associated with endometriosis. As all existing therapies of endometriosis are contraceptive, great efforts should be targeted at researching novel products that reduce the disease expression without shuttering ovulation.

Aromatase inhibitors for the treatment of endometriosis

OBJECTIVE

To review the use of aromatase inhibitors (AIs) for the treatment of endometriosis.

DESIGN

Literature review.

CONCLUSION(S)

Most studies show that in reproductive-age women, the combination of AI with conventional therapy alleviates endometriosis-related pain. In postmenopausal women, using an AI alone has been shown to be an effective treatment, although more studies are needed in this subgroup. Side effects of using AIs appear to be tolerable in most women, although special consideration should be given to monitoring bone mineral density. More studies need to be done examining pregnancy rates and outcomes after AI treatment for endometriosis. In addition, larger randomized clinical trials using AIs need to be done. In summary, AIs may be effective in treating endometriosis-related chronic pelvic pain in both reproductive-age and postmenopausal women.

New treatment strategies and emerging drugs in endometriosis

Introduction: Endometriosis, histologically defined as the presence of endometrium-like tissue - glands and stroma - that develops outside of the uterine cavity, is still an enigmatic disease responsible for pelvic pain and infertility. The current treatments of endometriosis are surgery and hormonal therapies that act by suppressing ovulation and/or directly on steroid receptors located in endometriotic lesions. Areas covered: New hormonal and non-hormonal therapies are being developed for the treatment of endometriosis-related pain. The authors review the state of advancement and the results of novel treatments studied in registered trials ( www.ClinicalTrials.gov ). Cellular signaling pathways activated in endometriotic cells, which constitute potential targets for future treatments, are also described. Expert opinion: Therapeutic research efforts should focus on identifying and testing substances capable of acting locally on the lesions themselves, without interfering with ovulation, in order to be efficacious on both pain symptoms and infertility.

Association Rate between Incisional and Pelvic Endometriosis

Purpose

To investigate the association rate between abdominal wall and pelvic endometriosis in a population of Iranian patients, in University and private hospitals of Shiraz University of Medical Sciences.

Methods

30 women were diagnosed as abdominal wall endometriosis according to the clinical signs and symptoms (dysmenorrhea, dyspauronia and pelvic pain) and the sonographic findings. The mean age of the patients was 30.5 ±3.3 (range 21–35) years. All the patients underwent resection of abdominal wall mass and investigation of the pelvic cavity for detecting pelvic endometriosis by laparoscopy. The pelvic endometriosis was scored and the stage was determined.

Results

28 (93.3%) patients were found to have concomitant pelvic endometriosis. The mean score of pelvic endometriosis was 9.3 ± 6.6 (range 3–33). Of the patients, 10 (33.3%) suffered from stage I endometriosis, 16 (53.3%) from stage II, and 2 (6.7%) from stage III. Only 2 (6.7%) patients did not have concomitant pelvic endometriosis. The abdominal wall mass was successfully excised in all the cases. The histopathology diagnosis was confirmed in all the cases.

Conclusions

The association rate between abdominal wall and pelvic endometriosis is higher than that previously reported, up to 90%. Thus, routine investigation of the pelvic cavity is recommended in all the patients with abdominal wall endometriosis.

Aromatase inhibition for refractory endometriosis-related chronic pelvic pain

OBJECTIVE

To evaluate the use of an aromatase inhibitor for the treatment of endometriosis-related chronic pelvic pain.

DESIGN

Retrospective analysis.

SETTING

Academic medical center outpatient reproductive endocrinology clinic.

PATIENT(S)

Sixteen patients with endometriosis and chronic pelvic pain who previously failed conventional medical and/or surgical therapy.

INTERVENTION(S)

Treatment with the aromatase inhibitor letrozole (2.5 mg/d) plus a gonadotropin suppressor (norethindrone acetate, 2.5 mg/d, or a combination oral contraceptive [OC]) for an average of 6 months.

MAIN OUTCOME MEASURE(S)

Pain scores were reported at each visit using a visual analogue scale from 0 to 10 (0: no pain, 10: maximum pain).

RESULT(S)

Sixteen patients were treated with an aromatase inhibitor for 180 ± 31 days. The median pain score at the start of therapy was 7, and at the end of therapy it was 1.5. In the nine patients who were evaluated after discontinuing therapy, pain scores returned to pretreatment levels. We did not find any correlation between the length of treatment and the overall improvement in pain score.

CONCLUSION(S)

Letrozole plus a gonadotropin suppressor substantially improved pain symptoms in patients with endometriosis refractory to conventional therapies; however, pain recurred after treatment was completed.

Letrozole and norethisterone acetate versus letrozole and triptorelin in the treatment of endometriosis related pain symptoms: a randomized controlled trial

BACKGROUND

When aromatase inhibitors are used to treat premenopausal women with endometriosis, additional drugs should be used to effectively down-regulate gonadal estrogen biosynthesis. This randomized prospective open-label study compared the efficacy in treating pain symptoms and the tolerability of letrozole combined with either norethisterone acetate or triptorelin.

METHODS

Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T). The scheduled length of treatment was 6 months. A visual analogue scale and a multidimensional categorical rating scale were used to assess the severity of pain symptoms. The volume of the endometriotic nodules was estimated by ultrasonography using virtual organ computer-aided analysis. Adverse effects of treatment were recorded.

RESULTS

A total of 35 women were randomized between the two treatment protocols. Significantly more patients in group N rated their treatment as satisfactory or very satisfactory (64.7%) as compared to group T (22.2%; p=0.028). The intensity of both non-menstrual pelvic pain and deep dyspareunia significantly decreased during treatment in both study groups, though no statistically meaningful difference between the two groups was apparent. Reduction in the volume of endometriotic nodules was significantly greater in group T than in group N. Interruption of treatment due to adverse effects significantly differed between the groups, with 8 women in group T (44.4%) and 1 woman in group N (5.9%) interrupting treatment (p=0.018). Similarly, 14 women included in group T (77.8%) and 6 women included in group N (35.3%) experienced adverse effects of treatment (p=0.018). During treatment, mineral bone density significantly decreased in group T but not in group N.

CONCLUSIONS

Aromatase inhibitors reduce the intensity of endometriosis-related pain symptoms. Combining letrozole with oral norethisterone acetate was associated with a lower incidence of adverse effects and a lower discontinuation rate than combining letrozole with triptorelin.

Use of aromatase inhibitors to treat endometriosis-related pain symptoms: a systematic review

This systematic review aims to assess the efficacy of aromatase inhibitors (AIs) in treating pain symptoms caused by endometriosis. A comprehensive literature search was conducted to identify all the published studies evaluating the efficacy of type II nonsteroidal aromatase inhibitors (anastrozole and letrozole) in treating endometriosis-related pain symptoms. The MEDLINE, EMBASE, PubMed, and SCOPUS databases and the Cochrane System Reviews were searched up to October 2010. This review comprises of the results of 10 publications fitting the inclusion criteria; these studies included a total of 251 women. Five studies were prospective non-comparative, four were randomized controlled trials (RCTs) and one was a prospective patient preference trial. Seven studies examined the efficacy of AIs in improving endometriosis-related pain symptoms, whilst three RCTs investigated the use of AIs as post-operative therapy in preventing the recurrence of pain symptoms after surgery for endometriosis. All the observational studies demonstrated that AIs combined with either progestogens or oral contraceptive pill reduce the severity of pain symptoms and improve quality of life. One patient preference study demonstrated that letrozole combined with norethisterone acetate is more effective in reducing pain and deep dyspareunia than norethisterone acetate alone. However, letrozole causes a higher incidence of adverse effects and does not improve patients' satisfaction or influence recurrence of symptoms after discontinuation of treatment. A RCT showed that combining letrozole with norethisterone acetate causes a lower incidence of adverse effects and lower discontinuation rate than combining letrozole with triptorelin. Two RCTs demonstrated that, after surgical treatment of endometriosis, the administration of AIs combined with gonadotropin releasing hormone analogue for 6 months reduces the risk of endometriosis recurrence when compared with gonadotropin releasing hormone analogue alone. In conclusion, AIs effectively reduce the severity of endometriosis-related pain symptoms. Since endometriosis is a chronic disease, future investigations should clarify whether the long-term administration of AIs is superior to currently available endocrine therapies in terms of improvement of pain, adverse effects and patient satisfaction.

Functional microRNA involved in endometriosis

Endometriosis is a common disease seen by gynecologists. Clinical features involve pelvic pain and unexplained infertility. Although endometriosis is pathologically characterized by endometrial tissue outside the normal uterine location, endometriosis is otherwise not easily explained. Endometriomas, endometriotic cysts of the ovary, typically cause pain and distortion of pelvic anatomy. To begin to understand the pathogenesis of endometriomas, we describe the first transcriptome-microRNAome analysis of endometriomas and eutopic endometrium using next-generation sequencing technology. Using this approach, we generated a total of more than 54 million independent small RNA reads from our 19 clinical samples. At the microRNA level, we found 10 microRNA that were up-regulated (miR-202, 193a-3p, 29c, 708, 509-3-5p, 574-3p, 193a-5p, 485-3p, 100, and 720) and 12 microRNA that were down-regulated (miR-504, 141, 429, 203, 10a, 200b, 873, 200c, 200a, 449b, 375, and 34c-5p) in endometriomas compared with endometrium. Using in silico prediction algorithms, we correlated these microRNA with their corresponding differentially expressed mRNA targets. To validate the functional roles of microRNA, we manipulated levels of miR-29c in an in vitro system of primary cultures of human endometrial stromal fibroblasts. Extracellular matrix genes that were potential targets of miR-29c in silico were significantly down-regulated using this biological in vitro system. In vitro functional studies using luciferase reporter constructs further confirmed that miR-29c directly affects specific extracellular matrix genes that are dysregulated in endometriomas. Thus, miR-29c and other abnormally regulated microRNA appear to play important roles in the pathophysiology of uterine function and dysfunction.