Combined down-regulation by aromatase inhibitor and GnRH-agonist in IVF patients with endometriomas—A pilot study

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.

Medical Management of Ovarian Endometriomas: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the effect of medical management on the size of ovarian endometriomas.

DATA SOURCE

Online databases were searched from inception to October 2022, including Ovid MEDLINE, Ovid EMBASE, PubMed, EBM Reviews-Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov , and Web of Science.

METHODS OF STUDY SELECTION

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we included all English-language, full-text articles that reported on change in endometrioma size (either diameter or volume) after medical interventions. Studies evaluating surgical interventions or postoperative recurrence were excluded. All screening and data extraction were performed independently by two authors. Risk of bias assessment was performed with either the Cochrane Risk of Bias Tool for randomized controlled trials or a modified Newcastle-Ottawa Scale for observational studies.

TABULATION, INTEGRATION, AND RESULTS

After removal of duplicates, 9,332 studies were screened, with 33 full-text articles deemed eligible for inclusion. In the meta-analysis, dienogest showed significant reduction in cyst diameter (reduction 1.32 cm, 95% CI, 0.91-1.73, eight studies, n=418 cysts) and volume (mean difference of log-transformed volume 1.35, 95% CI, 0.87-1.83, seven studies, n=282 cysts). Similarly, significant reductions were seen with the oral contraceptive pill (OCP) (1.06 cm, 95% CI, 0.59-1.53, nine studies, n=455), gonadotropin-releasing hormone (GnRH) agonists (1.17 cm, 95% CI, 0.42-1.92, four studies, n=128 cysts), norethindrone acetate (0.6 cm, 95% CI, 0.27-0.94, two studies, n=88 cysts), and danazol (1.95 cm, 95% CI, 1.18-2.73, two studies, n=34 cysts). Norethindrone acetate with aromatase inhibitor was also effective in reducing endometrioma volume (mean difference of log-transformed volume 1.47, 95% CI, 0.16-2.78, two studies, n=34 cysts).

CONCLUSION

Medical management with dienogest, OCPs, GnRH agonists, norethindrone acetate, norethindrone acetate with aromatase inhibitor, or danazol can reduce the size of ovarian endometriomas.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD 42022363319.

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.

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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.

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.

Pretreatment with a gonadotropin-releasing hormone agonist and an aromatase inhibitor may improve outcomes in in vitro fertilization cycles of women with stage I-II endometriosis

OBJECTIVE

To determine whether 2 months of pretreatment with 5 mg of letrozole daily plus leuprolide acetate at 3.75 mg monthly in women with laparoscopically confirmed American Society of Reproductive Medicine stage I-II endometriosis improves in vitro fertilization (IVF) outcomes.

DESIGN

Prospective cohort study.

SETTING

University-affiliated tertiary hospital.

PATIENT(S)

Women with laparoscopically confirmed endometriosis treated in the period from 2012 to 2016.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcomes: clinical pregnancy and live-birth rate; secondary outcomes: stimulation parameters and pregnancy.

RESULT(S)

A total of 68 patients were included in the final analysis. Thirty-six women received a gonadotropin-releasing hormone (GnRH) agonist and an aromatase inhibitor (AI), and 32 women received a GnRH agonist alone. The women did not differ in mean age, antral follicle count, basal serum level of follicle-stimulating hormone, or previous pregnancies. The stimulation parameters were similar between both groups: gonadotropin dose, number of collected oocytes, number of blastocysts. All women underwent a single blastocyst transfer. The grade of embryos transferred did not differ. Clinical pregnancy (24 [66.7%] vs. 13 [40.6%]) and live-birth (22 [61.1%] vs 10 [31.3%]) rates improved with aromatase inhibitor added to the GnRH agonist treatment versus a GnRH agonist alone.

CONCLUSION(S)

In this study, we present the first comparison in the medical literature comparing IVF outcomes in women with minimal and mild endometriosis pretreated with a GnRH agonist with or without an AI. This prospective cohort study suggests that combining these two treatment modalities which work at different sites may improve pregnancy outcomes with IVF treatment.

Effect of GnRH agonist and letrozole treatment in women with recurrent implantation failure

OBJECTIVE

To compare the influence of dual suppression with the use of GnRH agonist plus aromatase inhibitor compared with suppression with the use of GnRH agonist alone or no suppression at all in patients with idiopathic recurrent implantation failure (RIF).

DESIGN

Retrospective cohort study.

SETTING

University-affiliated reproductive center.

PATIENT(S)

A total of 523 infertile women who failed two blastocyst transfers underwent a third frozen blastocyst transfer. Women with known endometriosis were excluded.

INTERVENTION(S)

A total of 204 subjects were not pretreated, 143 received 2 months of GnRH agonist (3.75 mg intramuscular leuprolide acetate monthly) only, and 176 received GnRH agonist and aromatase inhibitor (5 mg oral letrozole daily for 60 days). Demographic and stimulation information was collected and cycle outcomes reported.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rates.

RESULT(S)

Age, antral follicle count, basal FSH levels, duration of infertility, previous pregnancies, and full-term deliveries were similar (P>.05). Clinical pregnancy rates were higher among women who received GnRH agonist plus letrozole compared with women who received GnRH agonist only or women without pretreatment (63%, 42%, and 40%, respectively; P<.0001). Live birth rates were higher among women who received GnRH agonist plus letrozole compared with the other groups (56%, 36%, and 34%; P<.0001). No differences in pregnancy outcomes were noted between patients who did not receive pretreatment and those in the GnRH agonist only group.

CONCLUSION(S)

In patients with RIF, treatment with a GnRH agonist plus letrozole may improve live birth rates in subsequent cycles. We hypothesize that this improvement is due to alterations in the endometrium receptivity or treatment of undiagnosed endometriosis.

[Management by assisted reproductive technology in women with endometriosis: CNGOF-HAS Endometriosis Guidelines]

Should the presence of endometriosis change the management of assisted reproductive technology? There is no difference in pregnancy rate after IVF between an agonist or antagonist protocol in patients with endometriosis, so the choice between one or the other of these protocols is free. But the review of the literature has shown an improvement in the chances of pregnancy in case of prolonged ovulation suppression before stimulation for IVF with a GnRH agonist analogue or with oral contraception, especially in cases of severe endometriosis. Endometriosis, regardless of the stage and type of lesions, would have no effect on the IVF results in terms of pregnancy rate and live birth rate, but with a lower number of oocytes collected, especially in cases of severe endometriosis. In a context of superficial endometriosis without pain and of infertility, surgical treatment of superficial endometriosis is not recommended just to increase the chances of pregnancy in IVF. Surgery may have a place in case of failure of IVF to improve the results of the ART. In case of recurrence of endometriosis, surgery is not better than IVF, a medico-surgical concertation is recommended. In addition, studies on ovulation stimulation for IVF do not show any aggravation of the symptoms associated with endometriosis lesions, or an acceleration of its progression, or an increase in the rate of recurrence of the disease.

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.

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.

Use of aromatase inhibitors in practice of gynecology

Purpose

The conversion of androgens into estrogens by aromatase is called aromatization and is inhibited by aromatase inhibitors (AIs). The aim of this article is to evaluate the use of aromatase inhibitors in gynecological diseases such as endometriosis, leiomyoma, estrogen- dependent gynecologic neoplasia and infertility.

Methods

This is a review of literature combined with experience and use of aromatase ınhıbıtors ın practıce of gynecology.

Conclusion

AIs are promising agents in treatment of estrogen dependent disease. However lack of experience, side effects and cost are limiting factors for using these agents in infertility treatment. However there is need for larger, well designed randomized trials to generate robust data in order to establish the true potential of aromatase inhibitors.

Impact of endometriosis and its staging on assisted reproduction outcome: systematic review and meta-analysis

OBJECTIVE

To evaluate whether the presence or severity of endometriosis affects the outcome of assisted reproductive techniques (ART).

METHODS

In this systematic review, all studies comparing the outcome of ART in women with and those without endometriosis, or at different stages of the disease, were considered eligible. We used either risk ratio (RR) or mean difference (MD) and their 95%CIs for comparisons. The primary outcome was live birth; the secondary outcome was clinical pregnancy. Miscarriage and the number of oocytes retrieved were examined as additional outcomes.

RESULTS

We included 92 studies in the review and 78 in the meta-analysis: 20,167 women with endometriosis were compared with 121,931 women without endometriosis, and 1703 women with Stage-III/IV endometriosis were compared with 2227 women with Stage-I/II endometriosis. The following results were observed for the comparison of women with endometriosis vs women without endometriosis: live birth, RR = 0.99 (95%CI, 0.92-1.06); clinical pregnancy, RR = 0.95 (95%CI, 0.89-1.02); miscarriage, RR = 1.31 (95%CI, 1.07-1.59); number of oocytes retrieved, MD = -1.56 (95%CI, -2.05 to -1.08). The following results were observed for the comparison of women with Stage-III/IV vs Stage-I/II endometriosis: live birth, RR = 0.94 (95%CI, 0.80-1.11); clinical pregnancy, RR = 0.90 (95%CI, 0.82-1.00); miscarriage, RR = 0.99 (95%CI, 0.73-1.36); number of oocytes retrieved, MD = -1.03 (95%CI, -1.67 to -0.39).

CONCLUSIONS

Women with endometriosis undergoing ART have practically the same chance of achieving clinical pregnancy and live birth as do women with other causes of infertility. No relevant difference was observed in the chance of achieving clinical pregnancy and live birth following ART when comparing Stage-III/IV with Stage-I/II endometriosis. The quality of the evidence for the additional examined outcomes was very low, not allowing meaningful conclusions to be drawn.

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 and IVF: are agonists really better? Analysis of 1180 cycles with the propensity score matching

OBJECTIVE

To compare the outcomes of patients with confirmed endometriosis undergoing in vitro fertilization (IVF)-embryo transfer (ET) treated with either gonadotropin-releasing hormone agonist (GnRHa) or gonadotropin-releasing hormone antagonist (GnRHant) using the propensity score (PS) matching.

DESIGN

Observational, retrospective analysis from January 2000 to December 2010.

SETTING

Private tertiary fertility clinic.

PATIENT(S)

Patients with endometriosis confirmed by ultrasound or surgery (American Fertility Society; AFS grades I-IV) that underwent an IVF-ET, stimulated with standard controlled ovarian hyperstimulation (COH) and GnRHa or GnRHant.

INTERVENTION(S)

A PS was assigned to all patients, which calculates the conditional probability of receiving a certain treatment; a higher PS (1) meant a higher probability of receiving treatment with GnRHa, and a lower PS (0) meant a higher probability of receiving GnRHant. The PS was calculated with a logistic regression model adjusted specifically for age, follicle stimulating hormone, antral follicle count and previous IVF cycles. All patients were divided into three groups according to their PS.

MAIN OUTCOME MEASURE(S)

pregnancy rate (PR) per cycle.

RESULTS

1180 patients were analyzed. Raw PR per cycle was 41.8% and 23.4%, and PR per ET was 44.3 and 27%, respectively. PR per cycle: 41.9 versus 30% in group A; in group B, 39.7% versus 36.4% and in group C, 15.4% versus 18.9%. The overall odds ratio for PR adjusted by PS was 1.10 [0.58-2.19].

CONCLUSIONS

After matching patients by PS, PR after COH with either GnRHa or GnRHant may be equally effective.

The use of aromatase inhibitors in in vitro fertilization

The use of aromatase inhibitors (AIs) in IVF patients remains controversial. AIs can be considered for ovulation induction for IVF in women who are normal and poor responders, are at risk of ovarian hyperstimulation syndrome or thrombosis, who have endometriosis, and/or are undergoing fertility preservation procedures as a result of estrogen-dependent cancers, primarily breast and endometrial cancers. Although the biologic plausibility of the capacity of AIs in IVF patients is promising, results should be interpreted with caution, because the efficacy of AIs needs to be proven in randomized trials.

New trends for the medical treatment of endometriosis

INTRODUCTION

Endometriosis is a benign sex hormone-dependent gynecological disease, characterized by the presence and growth of endometrial tissue outside the uterus; it affects 10% of women of reproductive age and is associated with infertility and pain. Treatment of endometriosis involves conservative or radical surgery, or medical therapies. The goals for endometriosis treatment may be the relief of pain and/or a successful pregnancy achievement in infertile patients. Treatment must be individualized with a multidisciplinary approach. The classical treatments carry adverse side effects and in some cases a negative impact on quality of life. New agents promise a distinct perspective in endometriosis treatment.

AREAS COVERED

The aim of this paper is to systematically review the literature evidence of new medical treatments for endometriosis, defined as pharmacological treatments not yet commonly available and currently under investigation.

EXPERT OPINION

These new medical therapies would be used associated with surgical treatment and, in the future, will render possible the association of hormone therapy with non-hormonal treatment for endometriosis.

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.

The emerging use of aromatase inhibitors for endometriosis treatment

Endometriosis is defined as the growth of endometrial tissue outside of the uterine cavity. The disease occurs primarily in women of reproductive age but recurrent endometriosis is also detected in post-menopausal women. Regardless of age, endometriosis is associated with pain and reduces the quality of life for millions of women world-wide. Conventional therapies focus on reducing systemic levels of estrogen which results in cessation of endometriotic implant growth and pain symptoms associated with the disease. However, these treatments are not effective in all women and are not without side effects. Based upon the discovery that endometriotic tissue over-expresses aromatase, an enzyme critical for estrogen production, emphasis has been placed upon the use of aromatase inhibitors for the treatment of endometriosis and its associated symptoms. This article will review the rationale behind the use of aromatase inhibitors in treating endometriosis and summarize those studies which have evaluated the use of aromatase inhibitors in the treatment of endometriosis and its associated symptoms.

Effect of androgen supplementation or modulation on ovarian stimulation outcome in poor responders: a meta-analysis

Many trials have evaluated the use of androgen supplements and androgen-modulating agents to improve outcome of poor responders undergoing IVF treatment. This study conducted a systematic review and meta-analysis of controlled trials of androgen adjuvants (testosterone, dehydroepiandrostereone) and the androgen-modulating agent (letrozole) in poor responders undergoing IVF treatment. Searches were conducted on MEDLINE, EMBASE, Cochrane Library, ISRCTN Register and ISI proceedings. All randomized and non-randomized controlled trials were included. Study selection, quality appraisal and data extraction were performed independently and in duplicate. The main outcome measure was clinical pregnancy rate. The secondary outcome measures were dose and duration of gonadotrophin use, cycles cancelled before oocyte retrieval, oocytes retrieved and ongoing pregnancy rates. A total of 2481 cycles in women considered as poor responders undergoing IVF/intracytoplasmic sperm injection (ICSI) treatment were included in nine controlled trials. Meta-analyses of these studies did not show any significant difference in the number of oocytes retrieved and ongoing pregnancy/live-birth rates with androgen supplementation or modulation compared with the control groups. There is currently insufficient evidence from the few randomized controlled trials to support the use of androgen supplementation or modulation to improve live birth outcome in poor responders undergoing IVF/ICSI treatment.