Adenomyosis: New Knowledge is Generating New Treatment Strategies

Dysregulated expression of GATA2 and GATA6 transcription factors in adenomyosis: implications for impaired endometrial receptivity

OBJECTIVE

To study the effect of adenomyosis on the localized expression of the GATA binding proteins 2 and 6 (GATA2 and GATA6) zinc-finger transcription factors that are involved in proliferation of hematopoietic and endocrine cell lineages, cell differentiation, and organogenesis, potentially leading to impaired endometrial implantation.

DESIGN

Laboratory based experimental study.

SETTING

Academic hospital and laboratory.

PATIENTS

Human endometrial stromal cells (HESCs) of reproductive age patients, 18-45 years of age, with adenomyosis were compared with patients with no pathology and leiomyomatous uteri as controls (n = 4 in each group, respectively). Additionally, midsecretory phase endometrial sections were obtained from patients with adenomyosis and control patients with leiomyoma (n = 8 in each group, respectively).

INTERVENTIONS

GATA2 and GATA6 immunohistochemistry and H-SCORE were performed on the midsecretory phase endometrial sections from adenomyosis and leiomyoma control patients (n = 8 each, respectively). Control and adenomyosis patient HESC cultures were treated with placebo or 10-8 M estradiol (E2), or decidualization media (EMC) containing 10-8 M E2, 10-7 M medroxyprogesterone acetate, and 5 × 10-5 M cAMP for 6 and 10 days. Additionally, control HESC cultures (n = 4) were transfected with scrambled small interfering RNA (siRNA) (control) or GATA2-specific siRNAs for 6 days while adenomyosis HESC cultures (n = 4) were transfected with human GATA2 expression vectors to silence or induce GATA2 overexpression.

MAIN OUTCOME MEASURES

Immunohistochemistry was performed to obtain GATA2 and GATA6 H-SCORES in adenomyosis vs. control patient endometrial tissue. Expression of GATA2, GATA6, insulin-like growth factor-binding protein 1 (IGFBP1), prolactin (PRL), progesterone receptor (PGR), estrogen receptor 1 (ESR1), leukemia inhibitory factor (LIF), and Interleukin receptor 11 (IL11R) messenger RNA (mRNA) levels were analyzed using by qPCR with normalization to ACTB. Silencing and overexpression experiments also had the corresponding mRNA levels of the above factors analyzed. Western blot analysis was performed on isolated proteins from transfection experiments.

RESULTS

Immunohistochemistry revealed an overall fourfold lower GATA2 and fourfold higher GATA6 H-SCORE level in the endometrial stromal cells of patients with adenomyosis vs. controls. Decidual induction with EMC resulted in significantly lower GATA2, PGR, PRL and IGFBP1 mRNA levels in HESC cultures from patients with adenomyosis patient vs. controls. Leukemia inhibitory factor and IL11R mRNA levels were also significantly dysregulated in adenomyosis HESCs compared with controls. . Silencing of GATA2 expression in control HESCs induced an adenomyosis-like state with significant reductions in GATA2, increases in GATA6 and accompanying aberrations in PGR, PRL, ESR1 and LIF levels. Conversely, GATA2 overexpression via vector in adenomyosis HESCs caused partial restoration of the defective decidual response with significant increases in GATA2, PGR, PRL and LIF expression.

CONCLUSION

In-vivo and in-vitro experiment results demonstrate that there is an overall inverse relationship between endometrial GATA2 and GATA6 levels in patients with adenomyosis who have diminished GATA2 levels and concurrently elevated GATA6 levels. Additionally, lower GATA2 and higher GATA6 levels, together with aberrant levels of important receptors and implantation factors, such as ESR1, PGR, IGFBP1, PRL, LIF, and IL11R mRNA in HESCs from patients with adenomyosis or GATA2-silenced control HESCs, support impaired decidualization. These effects were partially restored with GATA2 overexpression in adenomyosis HESCs, demonstrating a potential therapeutic target.

The impact of adenomyosis on IVF outcomes: a prospective cohort study

STUDY QUESTION

Does the presence of adenomyosis in women treated with IVF alter IVF outcomes?

SUMMARY ANSWER

Adenomyosis does not significantly alter IVF outcomes when adjusted for confounding factors including maternal age and smoking status.

WHAT IS KNOWN ALREADY

Studies evaluating adenomyosis and its impact on infertility, particularly when focusing on IVF, remain controversial. Many studies report that adenomyosis has a detrimental effect on IVF outcomes, however age is strongly related with both the prevalence of adenomyosis and worse reproductive outcomes.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study of women undergoing 4002 IVF cycles who had undergone a screening ultrasound assessing features of adenomyosis from 1 January 2016 to 31 March 2018 at a multi-site private fertility clinic. Of these women, 1228 fulfilled the inclusion criteria and commenced an IVF cycle, with a subset of 715 women undergoing an embryo transfer (ET). Women were defined as having adenomyosis if there was sonographic evidence of adenomyosis on ultrasound as per the Morphological Uterus Sonographic Assessment criteria, and were then compared to women without.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All women at a private multi-site IVF clinic who underwent a standardised ultrasound to identify features of adenomyosis and also commenced an IVF cycle were assessed for their outcomes. These included clinical pregnancy (defined as the presence of a gestational sac on ultrasound at 7 weeks’ gestation), clinical pregnancy loss, number of cancelled cycles, number of useful embryos for transfer or freezing and live birth rates. As a secondary aim, initiated stimulation cycles and those that had an ET were analysed separately to determine when an effect of adenomyosis on IVF might occur: during stimulation or transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

When adjusting for confounders, women with and without sonographic features of adenomyosis had no significant differences in most of their IVF outcomes including live birth rates.

LIMITATIONS, REASONS FOR CAUTION

Adenomyosis had a detrimental impact on IVF outcomes prior to adjusting for confounding factors. No allowance was made for the possibility that confounding factors may merely reduce the effect size of adenomyosis on IVF outcomes. Second, despite a power calculation, the study was underpowered as not all fresh cycles led to an ET.

WIDER IMPLICATIONS OF THE FINDINGS

This is one of the largest studies to evaluate adenomyosis and IVF outcomes, while also importantly adjusting for confounding factors. The results suggest that adenomyosis does not have the detrimental impact on IVF that has previously been suggested, possibly reducing the importance of screening for and treating this entity.

STUDY FUNDING/COMPETING INTEREST(S)

The study received no external funding. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

ACTRN12617000796381.

Role of angiogenesis in adenomyosis-associated abnormal uterine bleeding and subfertility: a systematic review

BACKGROUND

Adenomyosis commonly occurs with abnormal uterine bleeding (AUB) and is associated with subfertility and a higher miscarriage rate. Recent evidence showed abnormal vascularization in the endometrium in patients with adenomyosis, suggesting a role of angiogenesis in the pathophysiology of AUB and subfertility in adenomyosis and providing a possible treatment target.

OBJECTIVE AND RATIONALE

We hypothesized that the level of abnormal vascularization and expression of angiogenic markers is increased in the ectopic and eutopic endometrium of adenomyosis patients in comparison with the endometrium of control patients. This was investigated through a search of the literature.

SEARCH METHODS

A systematic search was performed in PubMed and Embase until February 2019. Combinations of terms for angiogenesis and adenomyosis were applied as well as AUB, subfertility or anti-angiogenic therapy. The main search was limited to clinical studies carried out on premenopausal women. Original research articles focusing on markers of angiogenesis in the endometrium of patients with adenomyosis were included. Studies in which no comparison was made to control patients or which were not published in a peer-reviewed journal were excluded. A second search was performed to explore the therapeutic potential of targeting angiogenesis in adenomyosis. This search also included preclinical studies.

OUTCOMES

A total of 20 articles out of 1669 hits met our selection criteria. The mean vascular density (MVD) was studied by quantification of CD31, CD34, von Willebrand Factor (vWF) or factor-VIII-antibody-stained microvessels in seven studies. All these studies reported a significantly increased MVD in ectopic endometrium, and out of the six articles that took it into account, four studies reported a significantly increased MVD in eutopic endometrium compared with control endometrium. Five articles showed a significantly higher vascular endothelial growth factor expression in ectopic endometrium and three articles in eutopic endometrium compared with control endometrium. The vascular and pro-angiogenic markers α-smooth muscle actin, endoglin, S100A13, vimentin, matrix metalloproteinases (MMPs), nuclear factor (NF)-kB, tissue factor (TF), DJ-1, phosphorylated mammalian target of rapamycin, activin A, folli- and myostatin, CD41, SLIT, roundabout 1 (ROBO1), cyclooxygenase-2, lysophosphatidic acid (LPA) 1,4-5, phospho signal transducer and activator of transcription 3 (pSTAT3), interleukin (IL)-6, IL-22 and transforming growth factor-β1 were increased in ectopic endometrium, and the markers S100A13, MMP-2 and -9, TF, follistatin, myostatin, ROBO1, LPA1 and 4-5, pSTAT3, IL-6 and IL-22 were increased in eutopic endometrium, compared with control endometrium. The anti-angiogenic markers E-cadherin, eukaryotic translation initiation factor 3 subunit and gene associated with retinoic-interferon-induced mortality 19 were decreased in ectopic endometrium and IL-10 in eutopic endometrium, compared with control endometrium. The staining level of vWF and two pro-angiogenic markers (NF-κB nuclear p65 and TF) correlated with AUB in patients with adenomyosis. We found no studies that investigated the possible relationship between markers of angiogenesis and subfertility in adenomyosis patients. Nine articles reported on direct or indirect targeting of angiogenesis in adenomyosis-either by testing hormonal therapy or herbal compounds in clinical studies or by testing angiogenesis inhibitors in preclinical studies. However, there are no clinical studies on the effectiveness of such therapy for adenomyosis-related AUB or subfertility.

WIDER IMPLICATIONS

The results are in agreement with our hypothesis that increased angiogenesis is present in the endometrium of patients with adenomyosis compared with the endometrium of control patients. It is likely that increased angiogenesis leads to fragile and more permeable vessels resulting in adenomyosis-related AUB and possibly subfertility. While this association has not sufficiently been studied yet, our results encourage future studies to investigate the exact role of angiogenesis in the etiology of adenomyosis and related AUB or subfertility in women with adenomyosis in order to design curative or preventive therapeutic strategies.

Endometriosis and adenomyosis are associated with increased risk of preterm delivery and a small-for-gestational-age child: a systematic review and meta-analysis

INTRODUCTION

The objective of this systematic review and meta-analysis was to evaluate the risk of preterm delivery and having a small-for-gestational-age (SGA) child in women with endometriosis and adenomyosis compared with women without these two diseases.

MATERIAL AND METHODS

Studies on endometriosis or adenomyosis and risk of preterm delivery and/or SGA infant were included. The systematic search was conducted for all published articles in PubMed and Embase published from 1950 to 2017 using specific search terms. After duplicates were removed, two authors independently reviewed all studies, initially based on title and subsequently based on abstract. Studies considered relevant were read in full text by both reviewers to identify if studies met the inclusion criteria.

RESULTS

The search found 21 studies on a total of 2 517 516 women meeting the inclusion criteria. Women with endometriosis had an increased odds of preterm delivery [odds ratio (OR) 1.47, 95% CI 1.28-1.69] and SGA infant (OR 1.26, 95% CI 1.04-1.549). Compared with endometriosis, adenomyosis implied an even higher odds of both preterm delivery (OR 3.09, 95% CI 1.88-5.09) and SGA infant (OR 3.23, 95% CI 1.71-6.09) as well.

CONCLUSIONS

Women with endometriosis or adenomyosis had a higher odds of preterm delivery and having a child that was SGA compared with women without endometriosis or adenomyosis. The odds of both adverse birth outcomes was highest among women with adenomyosis. The results suggest a closer prenatal monitoring among pregnant women with endometriosis or adenomyosis.

Adenomyosis and urinary system symptoms

OBJECTIVE

This study aims to investigate the presence and incidence of overactive bladder (OAB) syndrome in patients diagnosed with adenomyosis and to evaluate the impacts of urinary symptoms on the quality of life of the patients.

MATERIALS AND METHODS

A total of 108 individuals including 50 patients with adenomyosis and 58 controls who were admitted to the Obstetrics and Gynecology Department of Bursa, Cekirge State Hospital and Derince Training and Research Hospital between April 2015 and December 2015 were included. The Urogenital Distress Inventory (UDI-6) and Incontinence Impact Questionnaire (IIQ-7) were used to evaluate symptoms.

RESULTS

Irritative urinary symptoms such as nocturia and frequency were seen more frequently in the adenomyosis group (p = 0.001 and p = 0.035). Overactive bladder symptoms were more common in the adenomyosis group (p = 0.0001).

CONCLUSION

Our study showed that symptoms of urinary tract symptoms are common in patients with adenomyosis, which adversely affect the quality of life.

The significance and evolution of menstruation

Historically, the evolutionary origins of menstruation have been based on two theories: the ability to eliminate infectious agents carried to the uterus with spermatozoa and the comparative conservation of energy with menstruation compared to its absence. In the menstruating species, more recent theories have identified spontaneous decidualization as the key adaptive mechanism. Spontaneous decidualization is seen as a mechanism to provide the mother with protection from the invasive characteristics of the embryo. Physiologically, menstruation involves complex interactions of inflammation and vascular mechanisms to stabilize the endometrium and allow a regulated loss of endometrial tissues and blood. A variety of human illnesses can be better understood as vulnerabilities associated with these evolutionary developments, including recurrent pregnancy loss, placenta accreta, ectopic pregnancy, endometriosis, adenomyosis, dysmenorrhea, and chronic pelvic pain. While the evolutionary aspects of these diseases indicate why such illnesses can occur, in some instances, they also provide a basis for treatment, prevention and future research direction.

Myomas and Adenomyosis: Impact on Reproductive Outcome

Among uterine structural abnormalities, myomas and adenomyosis represent two distinct, though frequently coexistent entities, with a remarkable prevalence in women of reproductive age. Various mechanisms have been proposed to explain the impact of each of them on reproductive outcome. In respect to myomas, current evidence implies that submucosal ones have an adverse effect on conception and early pregnancy. A similar effect yet is not quite clear and has been suggested for intramural myomas. Still, it seems reasonable that intramural myomas greater than 4 cm in diameter may negatively impair reproductive outcome. On the contrary, subserosal myomas do not seem to have a significant impact, if any, on reproduction. The presence of submucosal and/or large intramural myomas has also been linked to adverse pregnancy outcomes. In particular increased risk for miscarriage, fetal malpresentation, placenta previa, preterm birth, placenta abruption, postpartum hemorrhage, and cesarean section has been reported. With regard to adenomyosis, besides the tentative coexistence of adenomyosis and infertility, to date a causal relationship among these conditions has not been fully confirmed. Preterm birth and preterm premature rupture of membranes, uterine rupture, postpartum hemorrhage due to uterine atony, and ectopic pregnancy have all been reported in association with adenomyosis. Further research on the impact of adenomyosis on reproductive outcome is welcome.

Expression Pattern of G-Protein-Coupled Estrogen Receptor in Myometrium of Uteri with and without Adenomyosis

Objective

To compare the expression of G-protein-coupled estrogen receptor (GPER) in the junctional zone and outer myometrium of the proliferative and secretory phases of women with and without adenomyosis.

Methods

A total of 76 women were included in this study, 42 with adenomyosis (proliferative phase, n = 23; secretory phases, n = 19) and 34 controls (proliferative phase, n = 16; secretory phases, n = 18). Protein and total RNA were extracted from the junctional zone (JZ) and outer myometrium (OM). GPER protein and mRNA expression levels were evaluated by the use of western blotting and real-time quantitative polymerase chain reaction (RT-qPCR).

Results

The expression of GPER protein and mRNA in women with adenomyosis was significantly higher than that of control subjects, both in the junctional zone and in the outer myometrium and both in the proliferative and in the secretory phases.

Conclusion

The significant and consistent increase in GPER expression in adenomyosis compared with control subjects, regardless of whether it was in the proliferative or secretory phases and regardless of whether it was in the JZ or OM, suggests that GPER plays an important role in the pathogenesis of the adenomyosis.

Molecular Characteristics of the Endometrium in Uterine Adenomyosis and Its Biochemical Microenvironment

Adenomyosis, which manifests with focally or diffusely scattered endometrial tissue within the uterine myometrium, is an endometriosis-like disease with controversial pathogenesis and compromised reproductive outcomes. This review, including the in vitro and in vivo studies performed on human or mouse models, is aimed to summarize the specific molecular characteristics of endometrium in the biochemical microenvironments of uterine adenomyosis. Many studies attributed the endometrium as the main cause of pathogenesis, with evidence of differential genetic expression and/or epigenetic modulation as well as estrogen-induced epithelial-mesenchymal transition. However, some studies indicated that the myometrium could play a role in the development of disease, based on findings of smooth muscle metaplasia and/or fibroblast-to-myofibroblast transdifferentiation by the influence of local biochemical factors. To date, it remains unclear whether adenomyosis is a genetically determined or a microenvironmentally induced disorder or whether the dysregulation of local factors may elicit the alteration of genetic expression in the endometrium. Similarly, it is uncertain whether the endometrial characteristics would remain consistent or could change along with a woman's reproductive life. Further longitudinal studies of the epigenetic controls or system biology are needed to elucidate the pathogenesis. Discovery of effective conservative treatments to improve the reproductive outcomes of patients with adenomyosis is still warranted.

Perfusion of the uterine junctional zone in nulliparous and primiparous women assessed by DCE-MRI, as a function of menstrual cycle and hormonal contraception

PURPOSE

To evaluate the perfusion parameters of inner and outer myometrium in healthy nulliparous and primiparous women who are and who are not currently using hormonal contraceptives by means of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

MATERIAL AND METHODS

We performed pelvic 1.5T DCE-MRI on 98 women: 18 nulliparous non-users, 30 nulliparous users, 12 primiparous non-users and 38 primiparous users of hormonal contraception (mean age respectively 26.4, 25.8, 30.23 and 28.18years). The nulliparous non-users underwent DCE-MRI investigations during their follicular, ovulatory and luteal phase. Perfusion parameters (iAUC/volume, Ktrans, Kep and Ve) were assessed in the anterior and posterior junctional zone (JZ), outer myometrium and cervix.

RESULTS

In nulliparous non-users, the mean Ktrans and iAUC/volume showed a decrease from follicular to luteal phase (0.82 vs 0.55min^-1 for Ktrans, p=0/027 and 1.28 vs 0.68 for iAUC/volume, p<0.001). The anterior JZ demonstrated lower Ktrans (p=0.050) and higher Kep (p=0.012), in nulliparous non-users, lower Ktrans in nulliparous users (p<0.001) and lower Ve in primiparous users (p=0.012) than the anterior outer myometrium. Ktrans at the anterior and posterior JZ wall in nulliparous users was lower than in non-users (p=0.001 and p=0.013) and Ve at the anterior JZ wall in primiparous users was lower than in non-users (p=0.044).

CONCLUSION

This study provides data on normal perfusion parameters of inner and outer myometrium, which may be potentially useful in assisted reproductive therapy.

Decreased Endometrial Expression of Leukemia Inhibitory Factor Receptor Disrupts the STAT3 Signaling in Adenomyosis During the Implantation Window

BACKGROUND

Adenomyosis was found to have negative impacts on embryo implantation. Leukemia inhibitory factor (LIF), proposed to be a molecular marker for endometrial receptivity, works through the LIF receptor (LIFR) on both the embryo and the endometrium. We aimed to evaluate the endometrial expression of LIF and LIFR and its subsequent signaling in patients with adenomyosis during the window of implantation (WOI).

METHODS

Endometrium was obtained during the WOI from patients with adenomyosis (age <45 years) who underwent hysterectomy and from age-matched controls who had no endometriosis or adenomyosis. The LIF and LIFR expressions were measured by polymerase chain reaction for messenger RNA expression, immunohistochemistry for protein intensity and localization, and immunofluorescent staining for colocalization. The ratio of signal transducer and activator of transcription 3 (STAT3) to extracellular signal-regulated kinase (ERK) phosphorylation was measured by Western blot of both the endometrium and the isolated human endometrial stromal cells (ESCs).

RESULTS

Patients with adenomyosis showed significantly and parallelly reduced LIF and LIFR expressions in the eutopic endometrium during WOI as compared with the control women and subsequently with remarkably reduced activation of STAT3 and ERK signaling. The significantly increased STAT3 and ERK phosphorylation induced by the LIF treatment in the cultured ESCs supported the linkage between the LIF-LIFR reaction and the signaling cascade.

CONCLUSION

Significant reduction in LIFR expression and the reduced activation of subsequent signaling strongly suggest a working model of how the implantation markers, LIF, may affect the endometrium of patients with adenomyosis. These molecular changes supported the declined implantation rates reported in patients with adenomyosis.

Adenomyosis: what is new?

Adenomyosis is described as the benign invasion of endometrium into the myometrium, with endometrial glands and stroma surrounded by the hypertrophic and hyperplastic myometrium. It may affect 20% of female population and most widely seen among perimenopausal and multiparous women. Its etiopathogenesis, diagnosis, clinical findings and current various treatment options will be discussed in this article.

Clinical applications of levonorgestrel-releasing intrauterine system to gynecologic diseases

The levonorgestrel-releasing intrauterine system (LNG-IUS), originally designed for contraception, has since been applied to various gynecologic diseases. This article summarizes the current status of clinical applications of LNG-IUS to the treatment of gynecologic diseases such as heavy menstrual bleeding, endometriosis, leiomyoma, adenomyosis, endometrial hyperplasia, and early-stage endometrial cancer.

Value of magnetic resonance imaging in diagnosis of adenomyosis and myomas of the uterus

STUDY OBJECTIVE

To estimate the diagnostic performance of magnetic resonance imaging (MRI) in detection of myomas and adenomyosis of the uterus.

DESIGN

Prospective cohort observational study (Canadian Task Force classification II-2).

SETTING

Department of obstetrics and gynecology, tertiary academic hospital.

PATIENTS

One hundred fifty-three consecutive women with an enlarged uterus accompanied by gynecologic symptoms and/or with an asymptomatic pelvic mass.

INTERVENTION

Total abdominal hysterectomy. All patients underwent MRI before the operation.

MEASUREMENTS AND MAIN RESULTS

The sensitivity, specificity, positive, and negative predictive value of MRI for the diagnosis of uterine pathology was calculated using histologic findings as the standard criterion for final diagnosis. Receiver operating characteristics curves were constructed to describe the diagnostic performance of MRI. In the diagnosis of myomas, MRI demonstrated sensitivity of 94.1%, specificity of 68.7%, PPV of 95.7%, and NPV of 61.1%. In the diagnosis of adenomyosis, MRI demonstrated sensitivity of 46.1%, specificity of 99.1%, PPV of 92.3%, and NPV of 88.5%. The area under the curve (AUC) for the diagnostic performance of MRI in the detection of myomas and adenomyosis was 0.81 and 0.73, respectively. Uterine sarcoma was diagnosed in 5 patients; in these cases, MRI demonstrated sensitivity of 60.0%, specificity of 99.2%, PPV of 75.0%, and NPV of 98.4%. The AUC for MRI in the diagnosis of uterine sarcomas was 0.80.

CONCLUSIONS

MRI exhibits a high AUC for the diagnosis of both adenomyosis and myomas. The PPV of MRI in the diagnosis of adenomyosis and myomas of the uterus is high as well. MRI seems to be a useful technique in everyday clinical practice in the diagnostic approach of these common conditions, enabling clinicians to select the most appropriate management.

The Endometrium in Adenomyosis

Eutopic and ectopic endometria of women with adenomyosis show a series of metabolic and molecular abnormalities that increase angiogenesis and proliferation, decrease apoptosis, allow local production of estrogens, create progesterone resistance, and impair cytokine expression. These changes enhance the ability of the endometrium to infiltrate the junctional zone myometrium and the growth of ectopic tissue. In addition, in these subjects several immunological abnormalities have been observed, together with an increased production of ‘free radicals’ leading to excessive growth of endometrial stromal cells that may facilitate the establishment of adenomyosis. A limiting factor is that these studies have been performed on hysterectomy specimens representing final stages of the disease. This increased knowledge has created new therapeutic options, including the block of local aromatase production through the use of selective estrogen receptor modulators, estrogen-progestin combinations and gonadotropin-releasing hormone super agonists. Also promising are investigations into the mechanism of dysmenorrhea and abnormal uterine bleeding.

Use of a murine endometriosis interna model for the characterization of compounds that effectively treat human endometriosis

Endometriosis is a chronic, estrogen-dependent disease characterized by the presence of ectopic endometrium either in the pelvic cavity (endometriosis externa) or within the uterus (endometriosis interna, adenomyosis). Key symptoms are pelvic pain, dysmenorrhea and infertility. Established rodent animal models used for drug research in endometriosis have certain limitations. Since rodents do not menstruate, they cannot develop endometriosis externa spontaneously, but they suffer from endometriosis interna. There is growing evidence that human endometriosis externa and interna represent two faces of the same disease. Both are estrogen-dependent and respond to similar treatment paradigms. Here, we addressed the question whether a murine endometriosis interna model may also be suitable for the characterization of drugs employed in human endometriosis. We examined the effects of danazol, Faslodex and cetrorelix in SHN mice that developed endometriosis interna after pituitary grafting. The GnRH antagonist cetrorelix and the estrogen receptor antagonist Faslodex, which negatively interfered with estrogen-mediated signaling, completely inhibited endometriosis interna, whereas danazol, an androgenic progestin, showed significant therapeutic activity in the majority of SHN mice. We conclude that this murine endometriosis interna model may be a valuable complement to established endometriosis externa models to support drug research in human endometriosis.

Infertility and adenomyosis

Classically, the diagnosis of adenomyosis has only been possible on a hysterectomy specimen, usually in women in their late fourth and fifth decades, and, therefore, evaluating any relationship with infertility was simply not possible. As a consequence, to this day, no epidemiologic data exists linking adenomyosis to a state of subfertility. Today, new imaging techniques have enabled a noninvasive diagnosis at a much earlier time and a number of single-case or small series reports have appeared showing that medical, surgical, or combined treatment can restore fertility in women with adenomyosis, an indirect proof of an association. At the functional level, several anomalies found in the so-called junctional zone, or inner myometrium, in adenomyosis patients have been shown to be associated with poor reproductive performance, mainly through perturbed uterine peristalsis. Additional evidence for an association comes from experimental data: in baboons, adenomyosis is associated with lifelong primary infertility, as well as to endometriosis. Finally, indirect proof comes from studies of the eutopic and ectopic endometrium in women with adenomyosis proving the existence of an altered endometrial function and receptivity. In conclusion, sufficient indirect proof exists linking adenomyosis to infertility to warrant systematic clinical studies.