Molecular basis for treating endometriosis with aromatase inhibitors

Chronic Pelvic Pain, Vulvar Pain Disorders, and Proteomics Profiles: New Discoveries, New Hopes

Chronic pelvic pain (CPP) is generally defined as non-cyclic pain perceived in the pelvic area that has persisted from three to six months or longer and is unrelated to pregnancy. The etiology of CPP is complex, multifactorial, with heterogeneous presentation, and includes several diseases such as endometriosis, adenomyosis, and interstitial cystitis/bladder pain syndrome. It may also be associated with sexual dysfunction, musculoskeletal disorders, and comorbid psychiatric symptoms. Vulvar pain disorders (VPDs) are typically categorized separately from chronic pelvic pain; among all VPDs, vulvodynia is a chronic vulvar pain of unknown etiology, lasting at least 3 months and that might be associated with other potentially linked factors. Proteomics represents a useful approach to study the proteome profiles of clinical samples. In this review, we have considered a selection of articles that have analyzed the protein abundance and novel protein species from various biological samples, including eutopic/ectopic endometrium, urine, serum, follicular, peritoneal fluid, and cervical mucus, potentially involved in the pathogenesis and progression of CPP and VPDs. These findings could represent valuable targets for paving the way for the differential diagnosis and therapeutic management of CPP and VDPs, thereby optimizing both the prevention and treatment of these conditions.

Expectant, Medical, and Surgical Management of Ovarian Endometriomas

Management options for ovarian endometriomas include expectant management, medical treatment, surgical treatment, in vitro fertilization (IVF), or a combination of the above. The choice of management depends on many clinical parameters that should be taken into consideration, the first of which is the main presenting symptom. Most patients are today referred to medical therapy as a first option in the case of associated pain, and to IVF in the case of associated infertility. When both symptoms are present, usually surgery is the preferred approach. Recently, however, surgical excision of an ovarian endometrioma has been associated with a postoperative reduction in the ovarian reserve, and recent guidelines suggest that the clinician should caution the patient as to the possible damage to the ovarian reserve in the case of surgery. However, evidence has been published as to a possible detrimental effect of the ovarian endometrioma on the ovarian reserve even if expectant management is followed. In this review, the current evidence on the conservative management of ovarian endometriomas, with particular focus on the issue of the ovarian reserve, is evaluated, and the different surgical techniques for the treatment of ovarian endometriomas are discussed.

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.

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

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

Anastrozole and levonorgrestrel-releasing intrauterine device in the treatment of endometriosis: a randomized clinical trial

BACKGROUND

To study the effectiveness of an aromatase inhibitor (Anastrozole) associated with levonorgestrel-releasing intrauterine device (LNG-IUD, Mirena®) in the treatment of endometriosis.

METHODS

Prospective, randomized clinical trial.

SETTING

University Hospital (single center). Elegibility criteria: Endometriomas > 3 × 4 cm, CA-125 > 35 U/mL and endometriosis symptoms.

PATIENTS

Thirty-one women randomized to anastrozole + Mirena® + Conservative Surgery(CS) (n = 8), anastrozole + Mirena® + transvaginal ultrasound-guided puncture-aspiration (TUGPA) (n = 7), Mirena® + CS (n = 9), or Mirena® + TUGPA (n = 7).

INTERVENTIONS

Anastrozole 1 mg/day and/or only Mirena® for 6 months; CS (ovarian and fertility-sparing) or TUGPA of endometriomas one month after starting medical treatment.

MAIN OUTCOME MEASURES

Visual analogic scale for symptoms, CA-125 levels, ultrasound findings of endometriomas and recurrences.

RESULTS

A significant improvement in symptoms during the treatment (difference of 43%, 95% CI 29.9-56.2) occurred, which was maintained at 1 and 2 years. It was more significant in patients including anastrozole in their treatment (51%, 95% CI 33.3-68.7). For CA-125, the most significant decrease was observed in patients not taking anastrozole (73.8%, 95% CI 64.2-83.4 vs. 53.8%, 95% CI 25.7-81.6 under Mirena® + anastrozole). After CS for endometriosis, a reduction of ultrasound findings of endometriomas and long-term recurrence occurred, with or without anastrozole. At 4.2 ± 1.7 years (95% CI 3.57-4.85), 88% of the patients who underwent CS were asymptomatic, without medication or reoperation, compared to only 21% if TUGPA was performed, with or without anastrozole (p = 0.019).

CONCLUSIONS

Dosing anastrozole for 6 months, starting one month before CS of endometriosis, reduces significantly the painful symptoms and delays recurrence, but has no other significant advantages over the single insertion of LNG-IUD (Mirena®) during the same time. Anastrozole and/or only Mirena® associated with TUGPA are not effective.

TRIAL REGISTRATION

Eudra CT System of the European Medicines Agency (London, 29-Sept-2008) Nº EudraCT: 2008-005744-17 (07/11/2008). Date of enrolment of first patient: 15/01/2009.

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.

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.

Effects of cisplatin on surgically induced endometriosis in a rat model

Research has strongly suggested that the features of endometriosis serve as a precursor lesion of ovarian cancer. Cisplatin (CDDP) is the preferred drug against these cancer types. The present study investigated the effects of CDDP on surgically induced endometriosis in a rat model. Endometriosis was surgically induced by the autologous transplantation of endometrial tissue. A total of 36 model rats were randomly divided into three groups. The rats in Group 1 (control group, n=12) received no medication. The rats in Group 2 (n=12) and Group 3 (n=12) were administered 35 mg/m² CDDP and 70 mg/m² CDDP, respectively, every four days. All rats were treated for a total of 24 days. The growth and histologic scores of the implants were calculated. The expression of protein markers, including vascular endothelial growth factor (VEGF), aromatase P450 (P450arom), transforming growth factor-β (TGF-β) and matrix metalloproteinase (MMP)-2, were assessed using immunohistochemistry, an enzyme-linked immunosorbent assay and western blot analysis. Following CDDP treatment, the mean implant sizes were significantly reduced in Groups 2 and 3 compared with the control group (P=0.01). The mean histologic scores were also significantly lower in Groups 2 and 3. Furthermore, the protein expression of VEGF, P450arom, TGF-β and MMP-2 was significantly lower in Groups 2 and 3 when compared with the control group. A loss of hair was observed in 4 rats, which only occurred in Group 3. A dose-dependent effect was observed in the two CDDP-treated groups. In conclusion, the expression of proliferation- and angiogenesis-associated proteins was significantly lower following treatment with CDDP. CDDP caused a significant regression in the size of the endometriotic implants and induced atrophy of these lesions in rats.

Expression of tumor suppressor programmed cell death 4 in endometrioid endometrial carcinomas and clinicopathological significance

Programmed cell death 4 (PDCD4), as a novel tumor suppressor, serves important roles in the pathogenesis of tumors. The expression of PDCD4 is downregulated or lost in various human tumors. However, the expression of PDCD4 in endometrial cancer and the clinicopathological significance remain unclear. The aim of the present study was to investigate the expression of PDCD4 in endometrioid endometrial carcinoma (EEC) and the association with clinicopathological parameters. The expression of PDCD4 in EEC tissues and control endometrium was detected by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. PDCD4 expression was also investigated in control endometrial glandular epithelial cells and the endometrial cancer KLE cell line by immunocytochemistry, and the association between PDCD4 expression and clinicopathological parameters of patients with EEC was analyzed. The results demonstrated that PDCD4-positive staining was mainly located in the cytoplasm of endometrial glandular epithelial cells and EEC cells. The staining index of PDCD4 in the proliferative phase was significantly increased compared with that in the secretory phase of control endometrium (P<0.001). There was significantly decreased PDCD4 expression in grade (G) 2/3 EEC tissues compared with the proliferative phase of control endometrium (P<0.001). PDCD4 expression was significantly associated with tumor grade. The PDCD4 levels in G1 EEC tissues were higher compared with the G2/3 EEC group (P<0.01). The results indicated that PDCD4 is associated with the histological grade of EEC, and that PDCD4 may be a valuable indicator of the degree of tumor malignancy in patients with EEC.

Future Directions in Endometriosis Research and Therapeutics

Background

Endometriosis is a disease common among women of reproductive age characterized by pain, anxiety and infertility. Defined as the growth of endometrial tissue in ectopic locations, endometriosis remains an enigmatic disease for which current treatments are less than ideal. Much of these shortcomings to current therapy stem from our incomplete understanding on the pathogenesis of the disease. It is generally accepted that endometriosis is an estrogen-dependent disease and, as such, the majority of treatment approaches aim at reducing estrogen action and/or production. Unfortunately, this approach is not effective in all women with endometriosis and in those women where success is achieved with their use, there is potential for health-comprising side effects.

Objective

The objective of this review is to summarize current approaches for treatment of endometriosis, discuss their limitations and potential reasons for lack of progress towards better therapeutics for this disease.

Results

In this review we summarize the current approaches for treatment of endometriosis, discuss their limitations and potential reasons for lack of progress towards better therapeutics for this disease.

Conclusion

Based upon the current state of knowledge, there is a strong necessity for through assessment at the level of the genome, miRNAome and proteome as well as the importance of integrating clinically-relevant endpoints in future studies which evaluate potential endometriosis therapies in experimental models of endometriosis.

Medical Management of Endometriosis

Endometriosis is a chronic medical condition that affects around 6% to 10% of reproductive age women. Pelvic pain, dysmenorrhea, and infertility are the most common presenting symptoms. The disease is characterized by estrogen-dependent growth of the endometrial glands and stroma outside the endometrial cavity. The diagnosis requires a high degree of suspicion and can be only confirmed on histopathology. Treatment includes medical and surgical options. Both hormonal and nonhormonal medical options are available and are tried at first with a goal to control pain and stop the growth of the endometriotic lesions. Nonsteroidal anti-inflammatory drugs, oral contraceptive pills, gonadotropin-releasing hormone (GnRH) agonists, aromatase inhibitors are some of the commonly used medications. With more research on the molecular and biochemical aspects of endometriosis, newer targets of therapy are being developed like selective progesterone receptor modulators, antiangiogenic factors and immunomodulators. In women who do not respond to medical therapy or have severe symptoms, surgical excision of the endometrial lesions and adhesions is often helpful and offers confirmatory diagnosis by histopathology.

TNFRp55 deficiency promotes the development of ectopic endometriotic-like lesions in mice

Endometriosis is an inflammatory disease depending on estradiol, with TNF-α being one of the most representative cytokines involved in its pathogenesis. TNF-α acts through its bond to the TNFRp55 and TNFRp75 membrane receptors. The aim of this study was to analyze the effect of the TNFRp55 deficiency on the development of ectopic endometriotic-like lesions. Endometriosis was induced surgically in mice of the C57BL/6 strain, wild type (WT) and TNFRp55-/- (KO). After four weeks, the peritoneal fluid was collected and the lesions were counted, measured with a caliper, removed, weighed, fixed or kept at -80°C. We evaluated the cell proliferation by proliferating cell nuclear antigen (PCNA) immunohistochemistry and apoptosis by TUNEL technique in the ectopic lesions. MMP-2 and MMP-9 activities (factors involved in invasiveness) were measured by zymography in the peritoneal fluid; estradiol and progesterone levels were measured by radioimmunoassay in the lesions and in the peritoneal fluid. We found that in KO animals the mean number of lesions established per mouse, the lesion volume, weight and cell proliferation increased and apoptosis decreased. In addition, the activity of MMP-2 and the estradiol level increased, whereas the progesterone level was not significantly modified. In conclusion, the deficiency of TNFRp55 promoted the establishment and development of endometriosis through an increase in the lesion size and high levels of estradiol which correlate with an increase in the MMP-2 activity. This is evidence of the possible association of the deregulation of the TNFRp55 expression and the survival of the endometriotic tissue in ectopic sites.

Involvement of 17β-hydroxysteroid dehydrogenase type gene 1 937 A>G polymorphism in infertility in Polish Caucasian women with endometriosis

Purpose

Endometriosis is considered to be an estrogen-related chronic inflammatory disease. The 17β-hydroxysteroid dehydrogenase 1 (HSD17B1) converts estrone to 17β estradiol. The role of HSD17B1 937 A>G (rs605059) single nucleotide polymorphism (SNP) in development of endometriosis is still disputable. This study evaluated the association of the HSD17B1 937 A>G (rs605059) SNP with infertile women affected by endometriosis from Polish Caucasian population.

Methods

The genotyping of cases (n = 290) and fertile women (n = 410) was conducted by high-resolution melting curve analysis.

Results

Statistical analysis demonstrated that the HSD17B1 937 A>G SNP is associated with endometriosis in stages I and II. The p_trend and p_allelic values calculated for the HSD17B1 937 A>G polymorphism were statistically significant and were equal to 0.001 and 0.0009, respectively. There was a significant association for the dominant model: (AG + GG vs AA) OR = 1.973 (95% CI = 1.178–3.304), p = 0.009, and for the recessive model: (GG vs AG + AA) OR = 1.806 (95% CI = 1.178–2.770), p = 0.006. However, we did not find statistical association of HSD17B1 937 A>G polymorphism with all infertile women with endometriosis or infertile women with endometriosis in stages III and IV.

Conclusion

Our genetic study demonstrated HSD17B1 937 G variant as a risk factor for infertility in women with stage I and II endometriosis in Polish Caucasian patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-017-0911-9) contains supplementary material, which is available to authorized users.

Pharmacologic treatment of the ovarian endometrioma

INTRODUCTION

Treatment of ovarian endometriomas is commonly achieved through laparoscopic surgery and this can be effective in eliminating the disease, although a majority of recent trials documented an adverse effect of surgery on ovarian reserve markers. With the advancement in imaging techniques, ovarian endometriomas are increasingly diagnosed at an earlier stage when the endometrioma may be smaller, less fibrotic and more responsive to medical treatment, making an evaluation of medical options critically important.

AREAS COVERED

The review focuses on currently utilized pharmacologic therapies for endometrioma (oral contraceptives, the levonorgestrel-releasing IUS, the hormone-releasing subdermal implant, Implanon); experimental and future treatments are also mentioned (GnRH antagonists, progesterone receptor modulators, antioestrogens, newer subdermal implants and intracystic administration of pharmacologic agents). Finally, the usefulness of post-operative adjuvant medical treatments is discussed Expert opinion: Today, reliable, non-invasive diagnostic procedures of an ovarian endometrioma are available and should be utilized to identify its presence and type of pathology. In a young patient, classic medical therapies such as oral contraceptives and synthetic progestins should be tried first to alleviate symptoms. Only when these regimens fail, should a minimally invasive surgery be envisaged. Following endoscopic surgery, adjuvant medical treatment may reduce recurrence of both symptoms and the lesion.

Selective Estrogen-Receptor Modulators and Aromatase Inhibitors: Promising New Medical Therapies for Endometriosis?

Endometriosis is an estrogen-dependent disease and estrogen-related pathways are imbalanced in women with endometriosis. One of the key enzymes in estrogen synthesis is aromatase. Inhibiting this pathway at several points is a promising idea for the treatment of endometriosis. The third generation of aromatase inhibitors is becoming more potent in efficacy, with fewer side effects than previous generations, but cotreatment with other hormones is needed to inhibit ovarian stimulation. Other components that promote estrogen synthesis such as COX-2 can also be potentially targeted. Selective estrogen-receptor modulators could also be interesting in view of their tissue-specific effect. However, all these new drugs are still in an early phase of development. At present, it is too early to conclude that aromatase inhibitors, COX-2 inhibitors or selective estrogen-receptor modulators really present any added value compared with the existing drugs that can be used to achieve hormonal suppression in the medical treatment of endometriosis.

Effect of Caffeic Acid Phenethyl Ester on the Regression of Endometrial Explants in an Experimental Rat Model

The objective of this study is to determine the effects of antioxidant and anti-inflammatory caffeic acid phenethyl ester (CAPE) on experimental endometriosis, peritoneal superoxide dismutase (SOD) and catalase (CAT) activities, and malondialdehyde (MDA) levels in the rat endometriosis model. Thirty rats with experimentally induced endometriosis were randomly divided into 2 groups and treated for 4 weeks with intraperitoneal CAPE (CAPE-treated group; 10 micromol/kg/d, n = 13) or vehicle (control group; n = 13). The volume and weight changes of the implants were calculated. Immunohistochemical and histologic examinations of endometriotic explants by semiquantitative analysis and measurements of peritoneal SOD, CAT, and MDA levels were made. Following 4 weeks of treatment with CAPE, there were significant differences in posttreatment spherical volumes (37.4 +/- 14.7 mm(3) vs 147.5 +/- 41.2 mm(3)) and explant weights (49.1 +/- 28.5 mg vs 158.9 +/- 50.3 mg) between the CAPE-treated groups and controls. The mean evaluation nomogram levels in glandular epithelium for COX-2 positivity by scoring system were 2.1 +/- 0.3 in the CAPE-treated group and 3.9 +/- 0.3 in the control group. In the CAPE-treated group, peritoneal levels of MDA and activities of SOD and CAT significantly decreased when compared with the control group (P < .01). Histologic analysis of the explants demonstrated mostly atrophy and regression in the treatment group, and semiquantitative analysis showed significantly lower scores in rats treated with CAPE compared with the control group. CAPE appeared to cause regression of experimental endometriosis.

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.

Retinoic acid has the potential to suppress endometriosis development

Background

Despite endometriosis is common estrogen dependent disease afflicting women in reproductive age, the pathogenesis has not been fully elucidated. Retinoic acid has various functions in cells as biologic modulator, and aberrant retinoid metabolism seems to be involved in the lesions of endometriosis. In order to evaluate the potential of all-trans retinoic acid (ATRA) for therapeutic treatment, a transcriptome analysis and estradiol measurements in cultured endometriotic cells and tissues were conducted.

Methods

The mRNA expression levels in ATRA-treated endometriotic stromal cells (ESC) isolated from ovarian endometrial cysts (OEC) were investigated. Estradiol production in OEC tissues was also investigated.

Results

In the isolated ESC culture supplemented with ATRA for four days, total RNA was extracted followed by a transcriptome analysis using GeneChip. Forty-nine genes were upregulated and four genes were down-regulated by the ATRA treatment. Many upregulated genes were associated with the negative regulation of cellular proliferation. In addition, ATRA treatment decreased the mRNA expression of 17-beta-dehydrogenase 2 (HSD17B2) which converts estradiol into estrone in a dose-dependent manner, and the ELISA measurements indicated that estradiol production in the OEC tissue was inhibited by ATRA treatment.

Conclusions

Retinoic acid has the potential to suppress endometriosis development.

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.

Western herbal medicine, epigenetics, and endometriosis

Endometriosis is an enigmatic disease characterized by the presence and growth of endometrial-like tissue outside the uterine cavity. The etiology of endometriosis is poorly understood, yet recent evidence suggests that epigenetic aberrations and heritable changes in the genome may be the key to understanding how to approach this disease. Difficulty in long-term management of endometriosis symptoms and unpredictability of treatment outcome necessitate research into other treatment modalities, such as Western herbal medicine. This article reviews commonly used herbs in the treatment of endometriosis, the effects of phytochemical constituents on endometrial cells, and the impact on the epigenome.

Role of inflammation and aromatase expression in the eutopic endometrium and its relationship with the development of endometriosis

Epigenetic changes favoring the transcription of the aromatase gene in the endometrium allow endometrial cells to survive in ectopic locations by producing estrogens that spare them from destruction through activated macrophages. Local estrogen production hastens prostaglandin synthesis by stimulating COX-2 activity, thus creating a self-perpetuating sequence of augmented estrogen formation and enhanced inflammation. Repetitive retrograde menstruation reintroduces aromatase-positive endometrial cells endowed with the capacity to implant and invade the peritoneum. In order to control endometriosis, an effective medication must inhibit aromatase, block COX-2, decrease fibrosis and induce amenorrhea. Within this framework, progestins, either alone or in the form of oral contraceptives, appear as first-line treatment for endometriosis owing to their capacity to block enzymes such as aromatase and COX-2.

Aromatase inhibitor treatment limits progression of peritoneal endometriosis in baboons

OBJECTIVE

To determine the effect of inhibiting aromatase activity on endometrial lesion growth and aromatase expression in a baboon model of induced endometriosis.

DESIGN

Prospective study.

SETTING

Primate research institute.

ANIMAL(S)

Sixteen olive baboons.

INTERVENTION(S)

Sixteen olive baboons with induced endometriosis were examined with laparoscopy 10 months after disease inoculation. Animals in group 1 (n = 10) were treated with 1.25 mg/d of the aromatase inhibitor (AI) letrozole, and animals in group 2 (n = 6) were given a placebo for a total of 6 months.

MAIN OUTCOME MEASURE(S)

Total number of endometriotic lesions, morphology, and volume of lesions, as well as semiquantitative reverse transcription-polymerase chain reaction and quantitative polymerase chain reaction for levels of aromatase cytochrome messenger RNA were measured. Ovarian volumes were evaluated before treatment initiation and every 2 months during the study.

RESULT(S)

Treatment of group 1 animals with an AI significantly decreased lesion volume from baseline measurements, whereas the placebo-treated animals showed an increase in lesion volume. Aromatase messenger RNA levels in lesions in the AI-treated animals were significantly lower compared with the placebo-treated animals. Ovarian volumes were significantly increased at 6 months of AI treatment compared with pretreatment volumes.

CONCLUSION(S)

These findings suggest that suppression of aromatase cytochrome P450 may inhibit the in vivo growth of endometriotic lesions in baboons.

Advantages of the association of resveratrol with oral contraceptives for management of endometriosis-related pain

BACKGROUND

The effect of resveratrol on the management of endometriosis-related pain was investigated in 12 patients who failed to obtain pain relief during use of an oral contraceptive containing drospirenone + ethinylestradiol.

METHODS AND RESULTS

The addition of 30 mg of resveratrol to the contraceptive regimen resulted in a significant reduction in pain scores, with 82% of patients reporting complete resolution of dysmenorrhea and pelvic pain after 2 months of use. In a separate experiment, aromatase and cyclo-oxygenase-2 expression were investigated in the endometrial tissue of 42 patients submitted to laparoscopy and hysteroscopy for the management of endometriosis. Sixteen of these patients were using oral contraceptives alone prior to hospital admission, while the remaining 26 were using them in combination with resveratrol. Inhibition of both aromatase and cyclo-oxygenase-2 expression was significantly greater in the eutopic endometrium of patients using combined drospirenone + resveratrol therapy compared with the endometrium of patients using oral contraceptives alone.

CONCLUSION

These results suggest that resveratrol potentiates the effect of oral contraceptives in the management of endometriosis-associated dysmenorrhea by further decreasing aromatase and cyclo-oxygenase-2 expression in the endometrium.

Endometriosis in Italy: from cost estimates to new medical treatment

Endometriosis is defined as the presence of endometrial-like tissue outside the uterus, which induced a chronic inflammatory reaction. The data collected from Italy showed that around 3 million women are affected by endoemtriosis and the condition was predominantly found in women of reproductive age (50% of women were in the 29-39 age range), only 25% of women were asymptomatic. The associated symptoms can create an impact in general physical, mental, and social well-being. Endometriosis is associated with severe dysmenorrhea, deep dyspareunia, chronic pelvic pain, ovulation pain, cyclical, or perimenstrual symptoms, with or without abnormal bleeding, infertility, and chronic fatigue. The annual cost for hospital admission can be estimated to be in a total around 54 million euros. The average time for right diagnosis is around 9 years still today and it follows a long and expensive diagnostic search. Therapies can be useful to relieve and sometimes solve the symptoms, encourage fertility, eliminate endometrial lesions, and restore the anatomy of the pelvis. For medical therapy, several different preparations (oral contraceptives, progestogenics, gestrinone, danazol, and GnRHa) and new options (GnRH antagonists, aromatase inhibitors, estrogen receptor beta agoinist, progesterone receptor modulators, angiogenesis inhibitors, and COX-2 selective inhibitors) are available.

Endometriosis: current therapies and new pharmacological developments

Endometriosis is a chronic inflammatory condition that is responsive to management with steroids. The establishment of a steady hormonal environment and inhibition of ovulation can temporarily suppress ectopic implants and reduce inflammation as well as associated pain symptoms. In terms of pharmacological management, the currently available agents are not curative, and treatment often needs to be continued for years or until pregnancy is desired. Similar efficacy has been observed from the various therapies that have been investigated for endometriosis. Accordingly, combined oral contraceptives and progestins, based on their favourable safety profile, tolerability and cost, should be considered as first-line options, as an alternative to surgery and for post-operative adjuvant use. In situations where progestins and oral contraceptives prove ineffective, are poorly tolerated or are contraindicated, gonadotrophin-releasing hormone analogues, danazol or gestrinone may be used. Future therapeutic options for managing endometriosis must compare favourably against existing agents before they can be considered for inclusion into current practice. Finally, as reproductive prognosis is not ameliorated by medical treatment, it is not indicated for women seeking conception.

Endometriosis, in vitro fertilisation and the risk of gynaecological malignancies, including ovarian and breast cancer

There is evidence that endometriosis as well as drugs used in the process of in vitro fertilisation appear to associate with increased risk for gynaecological cancer. In this review, we attempt to describe this relationship according to the most recent epidemiologic data and to present the possible mechanisms on the molecular level that could potentially explain this correlation. There are data to support that ovarian endometriosis could have the potential for malignant transformation. Epidemiologic and genetic studies support this notion. It seems that endometriosis is associated with specific types of ovarian cancer (endometrioid and clear cell). There is no clear association between endometriosis and breast or endometrial cancer. More studies are needed to establish the risk factors that may lead to malignant transformation of this condition and to identify predisposed individuals who may require closer surveillance. Currently, there is no proven relationship between any type of gynaecological cancer and drugs used for infertility treatment. In principle, infertile women have increased risk for gynaecologic malignancies. Nulligravidas who received treatment are at increased risk for malignancy compared with women who had conceived after treatment. There is limited evidence that clomiphene citrate use for more than six cycles or 900mg or treatment of women over the age of 40 could increase their risk for ovarian and breast cancer. More studies with the appropriate statistical power and follow-up time are required to evaluate accurately the long-term effects of these drugs and procedures.

Endometriosis and Chronic Pelvic Pain: Unraveling the Mystery Behind this Complex Condition

Nurses often encounter patients with chronic pelvic pain associated with endometriosis, which is a puzzling and problematic gynecologic condition that has continued to plague women and baffle doctors and researchers worldwide since it was first identified by Dr. J. Sampson in the 1920s (Sampson, 1940 ). Endometriosis is defined as the growth, adhesion and progression of endometrial glands and stroma outside of the uterine cavity, with cellular activity evident in lesions, nodules, cysts or endometriomas (Audebert et al., 1992 ). Although it typically appears benign on histopathology, endometriosis has been likened to a malignant tumor since the lesions grow, infiltrate and adhere to adjacent tissues and interfere with physiologic processes (Kitawaki et al., 2002 ; Noble, Simpson, Johns, & Bulun, 1996 ). Ectopic endometriotic growths respond to cyclic changes of estrogen and proliferate and shed in a manner similar to eutopic endometrium. This cyclic ectopic activity results in internal bleeding, formation of scar tissue, inflammation and sometimes debilitating chronic pain (Kitawaki et al.).

Endometriosis and Genetic Polymorphisms

Endometriosis is a benign gynecological disease with an unclear pathophysiology characterized by ectopic endometrium causing endometrium-like inflammatory lesions outside the uterine cavity. Recently, a number of studies have investigated genetic polymorphisms as a possible factor contributing to the development of endometriosis. In this review, we have summarized current data regarding genes with nucleotide polymorphisms investigated with regard to endometriosis. We searched PubMed for publications on endometriosis and polymorphism and found 108 publications between January 1979 and September 2005. These were classified according to the type of genetic polymorphism investigated and whether the result favored or did not favor association with endometriosis. We found a strikingly large amount of conflicting results. About 50% of the reviewed studies demonstrated positive correlations between different polymorphisms and endometriosis. This relation is most clearly seen in groups 1 (cytokines and inflammation), 2 (steroid-synthesizing enzymes and detoxifying enzymes and receptors), 4 (estradiol metabolism), 5 (other enzymes and metabolic systems), and 7 (adhesion molecules and matrix enzymes). Group 8 (apoptosis, cellcycle regulation, and oncogenes) seemed to be negatively correlated with the disease, whereas group 3 (hormone receptors), 6 (growth factor systems), and especially 9 (human leukocyte antigen system components) showed a relatively strong correlation. The review indicates that polymorphisms may have a limited value in assessing possible development of endometriosis.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall the complexity of attempting to link endometriosis to single nucleotide polymorphisms (SNPs), explain that the literature is varied on results and recommendations and is population specific, and state that there are some SNP relationships that are clinically stronger than others.

[Pathogenesis of endometriosis]

Endometriosis, defined by the development of endometrial tissue outside the uterus, is a benign disease responsible for infertility and pelvic pain. The diagnosis based on a detailed gynecological history and a careful clinical examination should be done as early as possible in order to treat patients correctly. Medical treatment is not appropriate in all cases and surgical treatment should be proposed but morbidity is related to the severity of the lesion. Ectopic implantation of endometrial cells needs complex interactions between host tissue and epithelial endometrial cells. The conditions for the development of endometriosis are estrogeno-dependent growth of endometrial cells, induction of angiogenesis and lymphangiogenesis. Principal cellular and molecular factors of angiogenesis, lymphangiogenesis and fibrosis should be identified in order to develop new therapeutic strategies of endometriosis.

Konservative Therapie der Endometriose

Endometriosis is the second most frequent benign disease of the female of reproductive age. In spite of extensive research, the etiology of this disease is still largely enigmatic. A causal therapy has not been found yet. Several drug therapy approaches are available but none offers a permanent cure of endometriosis. In addition, the range of side effects of the particular drug therapies has to be considered individually. The treatment of patients with endometriosis cannot be standardized but has to differentiate the individual factors and life circumstances of the patients.

Aromatase expression in endometriotic tissues and its relationship to clinical and analytical findings

OBJECTIVE

To study the relationship between aromatase expression in endometriotic tissues and clinical and laboratory findings.

DESIGN

Prospective basic and clinical research.

SETTING

University hospital.

PATIENT(S)

Sixty-two women with endometriosis, and 12 without endometriosis.

INTERVENTION(S)

Conservative surgery, or hysterectomy and adnexectomy, along with an immunohistochemical study of aromatase in endometriotic and nonendometriotic tissues.

MAIN OUTCOME MEASURE(S)

Symptoms of the disease, ultrasound and surgical findings, values of tumor markers, steroids and immunoglobulins, and recurrences after surgery.

RESULT(S)

We observed positive immunohistochemical expression for aromatase in endometriotic tissues from 38 patients (61.3%). Aromatase expression was negative in the rest of the tissues studied and in the 12 cases without endometriosis. Aromatase-positive patients had a higher number of endometriomas, more bilaterality, and more moderate-to-severe chronic pelvic pain. Also, infertility and associated leiomyomas were more frequent in these patients, though without significant differences. There were no differences in recurrence of the disease 1 year later. Estradiol and PRL levels were significantly higher, and IgG values lower, than in aromatase-negative patients. High values of blood sedimentation rate were more frequent in aromatase-negative patients.

CONCLUSION(S)

Molecular alterations such as the presence of aromatase in endometriotic tissues could be involved in the development or maintenance of endometriosis. Our findings suggest major severity, activity, and chronic pelvic pain in patients with aromatase in endometriotic tissue.

Two Unsuccessful Clinical Trials on Endometriosis and a Few Lessons Learned

In 1999, a phase II clinical trial on the use of fulvestrant to treat endometriosis was launched; yet after 7 years there is still no report on its outcome. In 2005, another trial on the use of raloxifene to treat endometriosis was terminated early due to unfavorable outcome. The two apparently unsuccessful clinical trials on endometriosis have taught us a few important lessons. First, we need to understand endometriosis through more basic research. We have also been reminded that human endometriosis trials differ from animal studies; anatomy and physiology are often divergent, and outcome measures are certainly different. Ectopic endometrium can differ significantly from eutopic tissue, and this issue needs to be more thoroughly explored. We believe human cell lines will prove to be an inexpensive and valuable tool for future preliminary evaluation of medical therapies as well as discerning pathophysiologic processes of the disease. Based on our current understanding of endometriosis, some concrete benchmarks can be established for testing or screening potential compounds in vitro. Finally, estrogen receptor modulators are often tissue-, cell-, and context-specific in their actions; they should not be simplistically grouped together nor should extrapolations from one compound to another be undertaken in a cavalier manner.

Effect of the menstrual cycle and oral contraceptives on aromatase and cyclooxygenase-2 expression in adenomyosis

OBJECTIVES

To determine whether aromatase expression in the eutopic endometrium and adenomyotic foci is affected by previous use of oral contraceptives containing gestodene, and to determine whether changes in cyclooxygenase-2 (COX-2) expression occur in adenomyosis during the menstrual cycle.

PATIENT AND METHODS

This was a retrospective cohort study carried out in paraffin-embedded endometrial tissue obtained from patients with a histological diagnosis of adenomyosis obtained during the proliferative (n = 25) and luteal (n = 10) phases of the menstrual cycle and following the use of continuous oral contraception with gestodene/ethinyl estradiol (n = 7). COX-2 and aromatase expression were measured in both eutopic endometrium and adenomyotic foci using immunohistochemical methods.

RESULTS

Aromatase expression was detected in 80% of the endometrial slices by immunohistochemistry. In positive cases, aromatase was mainly detected in the stromal cells of the eutopic endometrium, whereas in the adenomyotic foci this expression was negative in the majority of the cases. Oral contraceptives containing gestodene, on the other hand, were effective in suppressing aromatase expression in both eutopic and ectopic endometrium. COX-2 expression was detected by immunohistochemistry in the glandular epithelium of both eutopic endometrium and adenomyotic foci and there were no significant changes in its intensity throughout the menstrual cycle.

CONCLUSION

Aromatase expression in the eutopic endometrium and adenomyotic foci is suppressed by oral contraceptives containing gestodene. Increased aromatase activity may be responsible for the persistent COX-2 expression during the luteal phase.

Emerging drugs in endometriosis

Endometriosis is a common, estrogen-dependent, gynaecological disease, defined as the presence of endometrial-like tissue outside the uterus. Although several medications are used for treatment of the disease, they are associated with high recurrence rates, considerable side effects and limited duration of application. Due to these limitations and to the impact of endometriosis on the quality of life of affected women, their environment and the society, there is a great need for new drugs able to abolish endometriosis and its symptoms. Studies in recent years investigating the (patho)physiological mechanisms involved in disease aetiology have fostered the development of novel therapeutic concepts for endometriosis, by targeting the hypothalamic-pituitary-gonadal axis, by selective modulation of estrogenic and progestogenic pathways, by inhibiting angiogenesis or by interfering with inflammatory and immunological factors. This article presents a brief summary of the currently available medications and an overview regarding the development of some of the most interesting and/or most promising novel drug candidates for endometriosis.

Regulatory expression of lipoxin A4 receptor in physiologically estrus cycle and pathologically endometriosis

Expression of receptors for prostaglandin (PG) and leukotriene (LT) has been reported to detect in endometrium and smooth muscle of uterus, suggesting involvement of these arachidonic metabolites in endometrial pathology and reproductive biology. Lipoxin (LX), which is produced by lipoxygenases from arachidonic acid, has been characterized as an anti-inflammatory lipid mediator. Biological actions of Lipoxin A4 (LXA4) are mediated through the specific receptor. In order to know roles of LXA4 in female genitalia, expression of LXA4 receptor mRNA was quantified by real-time polymerase chain reaction. Significantly higher expression of the receptor was detected in endometrium and myometrium than ovary in normal rats. Expression of the receptor in endometrium was increased at stage of proestrus cycle under physiological condition. Exogenous administration of progesterone into female rats significantly reduced the expression, while administration of estradiol or pregnant mare serum gonadotropin (PMSG) did not. Both, endometrium in experimental endometriosis induced in rats and the tissues from patients with ectopic endometriosis showed a higher expression of LXA4 receptor compared to the normal tissues. In contrast, expressions of BLT1 and BLT2, receptors for leukotriene B4, did not change in the endometriosis. These observations suggest a possible role of LXA4 and the receptor under physiological estrus cycle and pathological condition as endometriosis.

Investigational drugs for endometriosis

Endometriosis is an enigmatic disease found in as many as 30% of reproductive age women. The symptoms for women who suffer from this malady vary but may include subfertility or chronic pelvic pain. Because endometriosis lesions rely on estradiol for growth, most of the existing drug regimens work by creating hypoestrogenism. Unfortunately, this leads to untoward side effects and alterations in ovulation and, subsequently, fertility potential. Newer drugs are currently under investigation that either create hypoestrogenemia more efficaciously or do not alter ovulation but still affect the growth of endometriosis. They target some of the pathophysiological pathways that are only now being elucidated, and include gonadotropin-releasing hormone antagonists, aromatase inhibitors, selective progesterone receptor modulators, angiogenesis inhibitors, matrix metalloprotease inhibitors, estrogen receptor beta-agonists and immune modulators.

Future Perspectives in the Medical Treatment of Endometriosis

In the last few years, our understanding of the pathogenesis of endometriosis at the cellular and molecular levels has improved significantly. This may give us the opportunity to use new, specific agents for the treatment of this disorder. Despite the effectiveness of the available treatments, novel therapeutic strategies may improve our ability to eliminate endometriotic lesions when present and to prevent the recurrence of endometriosis after surgical treatment. This review focuses on the new, experimental approaches to the medical treatment of endometriosis and its symptoms. The blockage of aromatase activity in endometriotic lesions with an aromatase inhibitor may represent a new step in the medical treatment of endometriosis. Preliminary clinical studies have demonstrated the efficacy of third-generation nonsteroidal aromatase inhibitors (ie, anastrozole and letrozole) in reducing the intensity of pain symptoms associated with the presence of endometriosis. The new selective progesterone receptor modulators may represent a valid hormonal treatment option. Therapeutic manipulation of the immune system through TNFalpha inhibitors may be beneficial in women with endometriosis. New pharmaceutical agents affecting inflammation, angiogenesis, and matrix metalloproteinase activity may prevent or inhibit the development of endometriosis. Further clinical trials may determine if these new therapies are superior to current medical treatment strategies for endometriosis.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning.

OBJECTIVES

After completion of this article, the reader should be able to describe the new experimental medical treatments of endometriosis, state that the clinical use of nonsteroidal aromatase inhibitors for endometriosis appears to be efficacious but is based on preliminary clinical data, and recall that the drugs used for endometriosis in the future may include manipulation of the immune system.

Aromatase inhibitors and cyclooxygenase-2 (COX-2) inhibitors in endometriosis: New questions—old answers?

The medical treatment of endometriosis needs to be optimized. Therapeutic management strategies for endometriosis-associated pain or recurrent disease are primarily aimed at downregulating ovarian function or antagonizing the effect of estrogen in ectopic endometrial implants. In this context, basic research is providing important results for the development of new, specific treatment modalities. Aromatase overexpression has recently been detected in endometriotic tissue. Aromatase (p450arom) is responsible for converting C19 androgens into estrogen in several types of human tissue. Aromatase activity causes local estrogen biosynthesis, which, in turn, stimulates prostaglandin E2 production by upregulating cyclooxygenase-2 (COX-2). Thus, a positive feedback cycle develops between the two systems. Another abnormality in endometriosis, the deficient 17beta-hydroxysteroiddehydrogenase type II (17beta-HSD-Type-II) expression, impairs the inactivation of estradiol to estrone. In contrast to the eutopic endometrium, these molecular aberrations increase the amount of local estradiol and prostaglandin E2 in endometriosis. In several human cell lines, prostaglandin and estrogen concentrations are associated with proliferation, migration, angiogenesis, apoptosis resistance and even invasiveness. Consequently, aromatase and COX-2 are thought to be promising new therapeutic targets. Thus, specific aromatase inhibitors (e.g. Letrozol/Femara, Anastrozol/Arimidex or Exemestan/Aromasin) or selective COX-2 inhibitors (e.g. Celecoxib/Celebrex, Rofecoxib/Vioxx, Valdecoxib/Bextra) are of great interest and should be studied in clinical trials in premenopausal woman with endometriosis to expand the spectrum of currently available treatment options.

Role of the vaginally administered aromatase inhibitor anastrozole in women with rectovaginal endometriosis: a pilot study

In the present nonrandomized pilot study we determined the role of the vaginally administered aromatase inhibitor anastrozole (0.25 mg anastrozole/d for 6 months) in the treatment of women with histologically proven rectovaginal endometriosis. In a series of 10 patients, dysmenorrhea, physical and social functioning, but not chronic pelvic pain and dyspareunia, improved during therapy.