Endometriosis

Expressions of natural cytotoxicity receptor, NKG2D and NKG2D ligands in endometriosis

Pathogenesis of endometriosis is still unknown, and the relationship between NK cell activating receptors and endometriosis remains to be explored. We investigated the expression of NCRs and NKG2D in NK cells in peripheral blood (PB) and peritoneal fluid (PF) as well as expression of NKG2D ligands in endometrial cells, and illuminated their relationship with ovarian endometriosis. 20 patients with ovarian endometriosis and 13 subjects for control group were recruited. Flow cytometry was used for examining expressions of NCRs and NKG2D on NK cells. In PF with endometriosis, the expressions of NKp30 (P = 0. 006) and NKG2D (P = 0. 010) on CD56⁺NK cells were decreased, whereas the expression of NKp46 (P = 0. 040) on CD16⁺NK cells was higher than that of control. Real time PCR and Western blotting were used for detecting expression of NKG2D ligands. mRNA level of NKG2D ligands on endometrial cells showed no noticeable difference. As for protein expression, the ULBP-2 expression on eutopic endometrial cells with pelvic endometriosis was lower than that on ectopic endometrial cells and eutopic endometrial cells without endometriosis (P < 0.05), and the ULBP-3 expression on ectopic endometrial cells was lower than that on eutopic endometrial cells with or without endometriosis (P < 0.05). These findings indicate that change of NKp30, NKp46 and NKG2D on NK cells in PF and ULBP-2, 3 on endometrial cells may relate to the pathogenesis of pelvic endometriosis. Especially, change of NK cell activating receptors in PF implies that pelvic endometriosis is probably due to local immune changes.

National trends in inpatient endometriosis admissions: Patients, procedures and outcomes, 2006-2015

INTRODUCTION

Despite guidance towards minimally invasive, outpatient procedures for endometriosis, many patients nonetheless receive inpatient care. Our objective was to assess trends in patient and hospital characteristics, surgical complications and hospital charges for women with an endometriosis-related inpatient admission in the United States.

METHODS

We conducted a pooled cross-sectional analysis of Healthcare Cost and Utilization Project Nationwide Inpatient Sample data. Visits were stratified into three time-period-defined cohorts (2006-2007, 2010-2011, and 2014 through the first three quarters of 2015). Visits were included if the patient was aged 18-49 years and the primary diagnosis code was for endometriosis (International Classification of Diseases, 9th Revision code 617.xx). We evaluated counts of inpatient admissions and rates of patient and hospital characteristics.

RESULTS

The number of inpatient admissions with a primary diagnosis code for endometriosis decreased by 72.8% from 2006 to 2015. At the same time, among those admitted for inpatient care for endometriosis, the proportions who had Medicaid insurance and multiple documented comorbidities increased. From 2006 to 2015, mean total hospital charges increased by 75% to $39,662 in 2015 US dollars, although average length of stay increased by <1 day.

CONCLUSIONS

The number of inpatient admissions with a primary diagnosis of endometriosis decreased over the past decade, while surgical complications and associated hospital charges increased. The share of patients with multiple comorbidities increased and an increasing proportion of inpatient endometriosis admissions were covered by Medicaid and occurred at urban teaching hospitals. These findings suggest a demographic shift in patients receiving inpatient care for endometriosis towards more complex, vulnerable patients.

NK Cells as Potential Targets for Immunotherapy in Endometriosis

Endometriosis is a common gynecological disease defined by the presence of endometrial-like tissue outside the uterus, most frequently on the pelvic viscera and ovaries, which is associated with pelvic pains and infertility. It is an inflammatory disorder with some features of autoimmunity. It is accepted that ectopic endometriotic tissue originates from endometrial cells exfoliated during menstruation and disseminating into the peritoneum by retrograde menstrual blood flow. It is assumed that the survival of endometriotic cells in the peritoneal cavity may be partially due to their abrogated elimination by natural killer (NK) cells. The decrease of NK cell cytotoxic activity in endometriosis is associated with an increased expression of some inhibitory NK cell receptors. It may be also related to the expression of human leukocyte antigen G (HLA-G), a ligand for inhibitory leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) receptors. The downregulated cytotoxic activity of NK cells may be due to inhibitory cytokines present in the peritoneal milieu of patients with endometriosis. The role of NK cell receptors and their ligands in endometriosis is also confirmed by genetic association studies. Thus, endometriosis may be a subject of immunotherapy by blocking NK cell negative control checkpoints including inhibitory NK cell receptors. Immunotherapies with genetically modified NK cells also cannot be excluded.

The Origin and Pathogenesis of Endometriosis

Recent molecular genetic findings on endometriosis and normal endometrium suggest a modified model in which circulating epithelial progenitor or stem cells intended to regenerate uterine endometrium after menstruation may become overreactive and trapped outside the uterus. These trapped epithelium-committed progenitor cells form nascent glands through clonal expansion and recruit polyclonal stromal cells, leading to the establishment of deep infiltrating endometriosis. Once formed, the ectopic tissue becomes subject to immune surveillance, resulting in chronic inflammation. The inflammatory response orchestrated by nuclear factor-κB signaling is exacerbated by aberrations in the estrogen receptor-β and progesterone receptor pathways, which are also affected by local inflammation, forming a dysregulated inflammation-hormonal loop. Glandular epithelium within endometriotic tissue harbors cancer-associated mutations that are frequently detected in endometriosis-related ovarian cancers. In this review, we summarize recent advances that have illuminated the origin and pathogenesis of endometriosis and have provided new avenues for research that promise to improve the early diagnosis and management of endometriosis.

Endometriosis and Risk of Adverse Pregnancy Outcomes

OBJECTIVE

To investigate the relationship between endometriosis and adverse pregnancy outcomes.

METHODS

Women between ages 25 and 42 years in 1989 (n=116,429) reported detailed information on pregnancies and reproductive health at baseline and every 2 years thereafter in the Nurses' Health Study II, a cohort study. In 2009, they completed a detailed, pregnancy-focused questionnaire. A total of 196,722 pregnancies were reported. Adverse pregnancy outcomes included spontaneous abortion, ectopic pregnancy, stillbirth, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (preeclampsia or gestational hypertension), preterm birth, and low birth weight. We estimated the relative risks (RRs) and 95% CIs of adverse pregnancy outcomes comparing pregnancies in women with and without a history of laparoscopically confirmed endometriosis using multivariable log-binomial regression, with generalized estimating equations to account for multiple pregnancies per woman.

RESULTS

Endometriosis was associated with a greater risk of pregnancy loss (spontaneous abortion: RR 1.40, 95% CI 1.31-1.49; ectopic pregnancy: RR 1.46, 95% CI 1.19-1.80). Endometriosis was also associated with a greater risk of GDM (RR 1.35, 95% CI 1.11-1.63) and hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.16-1.45).

CONCLUSIONS

We observed an association between laparoscopically confirmed endometriosis and several adverse pregnancy outcomes. Future research should focus on the potential biological pathways underlying these relationships to inform screening or preventive interventions.

Reduced microRNA-451 expression in eutopic endometrium contributes to the pathogenesis of endometriosis

BACKGROUND

Endometriosis (EMs) is a chronic and recurrent, but benign, disease in women of reproductive age, and EMs patients have a high risk of developing gynecological tumors and autoimmune disorders. The etiology of EMs is not clear. Certain genetic markers in the eutopic endometrium are key in the pathogenesis of EMs. MicroRNAs (miRNAs) are implicated in several biological processes, such as cell proliferation, differentiation, and apoptosis. MiR-451 is interesting, as it acts as a tumor suppressor and is relevant to the poor prognosis of cancers.

AIM

To evaluate the expression levels and role of miR-451 in the eutopic endometrium and predict possible targets of miR-451 and related signaling pathways.

METHODS

Quantitative real-time polymerase chain reaction was used to evaluate miR-451 expression in cultured cell lines as well as in pathologic tissues from 40 patients with EMs and 20 donors with no history of the disease (controls). Cell Counting Kit-8 and flow cytometric assays were performed to determine cell proliferation and survival rates after transfection with miR-451 mimics and siRNAs. MiR-451 targets were predicted using miRDB and miRcode target-predicting databases.

RESULTS

We observed lower miR-451 levels in eutopic endometrial tissues from patients with EMs than in control tissues, and this difference was not related to the American Society for Reproductive Medicine stage. Ectopic overexpression of miR-451 in eutopic cells induced apoptosis and inhibited cell proliferation. SiRNA-mediated miR-451 knockdown reversed these effects. Using miRDB and miRcode, we identified 12 potential miR-451 target genes. We hypothesize that the expression of YWHAZ, OSR1, TTN, and CDKN2D may be regulated by miR-451 and be involved in disease pathogenesis.

CONCLUSION

Reduced miR-451 expression in the eutopic endometrium contributes to the pathogenesis of EMs by promoting cell proliferation and reducing apoptosis. Thus, miR-451 is a novel biomarker for EMs. YWHAZ, OSR1, TTN, and CDKN2D are potential target genes of miR-451 and may have key roles in this disease.

Clinical evaluation of the oral gonadotropin-releasing hormone-antagonist elagolix for the management of endometriosis-associated pain

Endometriosis is an estrogen-dependent chronic inflammatory disease associated with pelvic pain symptoms that are often severe, mainly dysmenorrhea, nonmenstrual pelvic pain and dyspareunia. This condition is also associated with peripheral and central sensitization. The current medical treatment options for endometriosis-associated pain are limited. Recently, the US FDA approved the novel, oral, nonpeptide gonadotropin-releasing hormone antagonist elagolix for the management of moderate to severe endometriosis-associated pain. Elagolix produces dose-dependent estrogen suppression, from partial suppression at lower doses to nearly full suppression at higher doses. This review article summarizes the current understanding of the pathophysiology of endometriosis, with a focus on the role of estrogen and the mechanisms of pain symptoms, and reviews the clinical development of elagolix in women with endometriosis-associated pain.

Clinical aspects and management of inguinal endometriosis: A case series of 20 patients

AIM

This study aimed to describe the clinical presentation, diagnostic evaluation, and operative or medical management of inguinal endometriosis.

METHODS

In this study, we retrospectively reviewed 20 cases of inguinal endometriosis in our facility, particularly on the clinical characteristics, diagnosis, and surgical and medical treatment.

RESULTS

We retrospectively investigated the following items for each patient: age at diagnosis, surgical history, presence of extragenital endometriosis, symptoms, imaging modalities, surgical therapy, hormonal therapy, follow-up period, postoperative recurrence and time to recurrence. We identified 20 cases of inguinal endometriosis in our facility. First, 75% of the patients had right inguinal endometriosis. Second, T1-weighted or fat-saturated T1-weighted images showed hyperintensity in the lesions in 17 patients (17/18 patients, 94.4%). Third, in 5 of 6 patients who underwent surgical therapy, we performed radical surgery to excise the inguinal lesion including the round ligament. One patient had disease relapse. Fourth, in 6 of 7 cases, dienogest effectively improved pain without significant adverse effects, but oral contraceptive was effective in 1 of 4 patients without significant adverse effects.

CONCLUSION

We retrospectively reviewed 20 patients with inguinal endometriosis in our facility. We have shown that magnetic resonance imaging can be a useful imaging modality to obtain a specific diagnosis of this disease. In addition, inguinal endometriosis can be managed with radical surgery to resect lesions including the round ligament and with hormonal treatment. In particular, dienogest ameliorated symptoms, which can be an option for patients who do not want surgery.

Progesterone and Estrogen Signaling in the Endometrium: What Goes Wrong in Endometriosis?

In the healthy endometrium, progesterone and estrogen signaling coordinate in a tightly regulated, dynamic interplay to drive a normal menstrual cycle and promote an embryo-receptive state to allow implantation during the window of receptivity. It is well-established that progesterone and estrogen act primarily through their cognate receptors to set off cascades of signaling pathways and enact large-scale gene expression programs. In endometriosis, when endometrial tissue grows outside the uterine cavity, progesterone and estrogen signaling are disrupted, commonly resulting in progesterone resistance and estrogen dominance. This hormone imbalance leads to heightened inflammation and may also increase the pelvic pain of the disease and decrease endometrial receptivity to embryo implantation. This review focuses on the molecular mechanisms governing progesterone and estrogen signaling supporting endometrial function and how they become dysregulated in endometriosis. Understanding how these mechanisms contribute to the pelvic pain and infertility associated with endometriosis will open new avenues of targeted medical therapies to give relief to the millions of women suffering its effects.

Assessing research gaps and unmet needs in endometriosis

Endometriosis, a systemic disease that is often painful and chronic, affects ∼10% of reproductive-age women. The disease can have a negative impact on a patient's physical and emotional well-being, quality of life, and productivity. Endometriosis also places significant economic and social burden on patients, their families, and society as a whole. Despite its high prevalence and cost, endometriosis remains underfunded and underresearched, greatly limiting our understanding of the disease and slowing much-needed innovation in diagnostic and treatment options. Due in part to the societal normalization of women's pain and stigma around menstrual issues, there is also a lack of disease awareness among patients, health care providers, and the public. The Society for Women's Health Research convened an interdisciplinary group of expert researchers, clinicians, and patients for a roundtable meeting to review the current state of the science on endometriosis and identify areas of need to improve a woman's diagnosis, treatment, and access to quality care. Comprehensive and interdisciplinary approaches to disease management and increased education and disease awareness for patients, health care providers, and the public are needed to remove stigma, increase timely and accurate diagnosis and treatment, and allow for new advancements.

Endometrial Stromal Cells Circulate in the Bloodstream of Women with Endometriosis: A Pilot Study

Endometriosis is characterized by the presence of endometrial tissue outside the uterus. While endometriotic tissue is commonly localized in the pelvic cavity, it can also be found in distant sites, including the brain. The origin and pathophysiology of tissue migration is poorly understood; retrograde menstruation is thought to be the cause, although the presence of endometrium at distant sites is not explained by this hypothesis. To determine whether dissemination occurs via the bloodstream in women with endometriosis, we analyzed circulating blood for the presence of endometrial cells. Circulating endometrial stromal cells were identified only in women with endometriosis but not in controls, while endometrial epithelial cells were not identified in the circulation of either group. Our results support the hypothesis that endometrial stromal cells may migrate through circulation and promote the pathophysiology of endometriosis. The detection of these cells in circulation creates avenues for the development of less invasive diagnostic tools for the disease, and opens possibilities for further study of the origin of endometriosis.

Discovery and optimization of pyridyl-cycloalkyl-carboxylic acids as inhibitors of microsomal prostaglandin E synthase-1 for the treatment of endometriosis

Here we report on novel and potent pyridyl-cycloalkyl-carboxylic acid inhibitors of microsomal prostaglandin E synthase-1 (PTGES). PTGES produces, as part of the prostaglandin pathway, prostaglandin E2 which is a well-known driver for pain and inflammation. This fact together with the observed upregulation of PTGES during inflammation suggests that blockade of the enzyme might provide a beneficial treatment option for inflammation related conditions such as endometriosis. Compound 5a, a close analogue of the screening hit, potently inhibited PTGES in vitro, displayed excellent PK properties in vitro and in vivo and demonstrated efficacy in a CFA-induced pain model in mice and in a rat dyspareunia endometriosis model and was therefore selected for further studies.

The association between endometriosis and autoimmune diseases: a systematic review and meta-analysis

BACKGROUND

Endometriosis is a chronic gynaecological disorder that affects 2-10% of women of reproductive age. The aetiology of endometriosis is largely under-explored, yet abnormalities in the immune system have been suggested to explain the origin of ectopic endometrial tissues, and an association between endometriosis and autoimmune diseases has been proposed. Evaluation of current evidence investigating the association between endometriosis and autoimmune diseases from population-based studies will facilitate our understanding of the causes and consequences of endometriosis and provide a reference for better healthcare practices population-wide.

OBJECTIVE AND RATIONALE

The aim of this study was to systematically review the literature on population-based studies investigating an association between endometriosis and autoimmune diseases and to conduct a meta-analysis of combinable results to investigate the extent and robustness of evidence.

SEARCH METHODS

Four electronic databases were searched (MEDLINE, Embase, Web of Science, and CINAHL) from each database inception date until 7 April 2018. Search terms included a combination of database-specific controlled vocabulary terms and free-text terms relating to 'endometriosis' and 'autoimmune diseases'. Study inclusion criteria focused on peer-reviewed published articles that reported an association between endometriosis and autoimmune diseases, excluding case reports/series, review papers, meta-analyses, organizational guidelines, editorial letters, expert opinions, and conference abstracts. Quality assessment of included studies was performed based on GRADE criteria. Key information of eligible studies was abstracted into a standard form. Meta-analysis was performed for autoimmune diseases with combinable study results from at least three studies investigating an association with endometriosis. For cross-sectional studies and case-control studies, raw data from each study were documented to calculate a Mantel-Haenszel odds ratio with 95% CIs. For cohort studies, an inverse variance probability weighted model was used to pool study results to calculate a rate ratio (a hazard ratio or a standardized incidence rate) with 95% CIs.

OUTCOMES

A total of 26 published population-based cross-sectional, case-control, and cohort studies that investigated the association between endometriosis and autoimmune diseases met all eligible criteria and were included in the review. The studies quantified an association between endometriosis and several autoimmune diseases, including systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), rheumatoid arthritis (RA), autoimmune thyroid disorder, coeliac disease (CLD), multiple sclerosis (MS), inflammatory bowel disease (IBD), and Addison's disease. However, the quality of the evidence was generally poor due to the high risk of bias in the majority of the chosen study designs and statistical analyses. Only 5 of the 26 studies could provide high-quality evidence, and among these, 4 supported a statistically significant association between endometriosis and at least 1 autoimmune disease: SLE, SS, RA, CLD, MS, or IBD.

WIDER IMPLICATIONS

The observed associations between endometriosis and autoimmune diseases suggest that clinicians need to be aware of the potential coexistence of endometriosis and autoimmune diseases when either is diagnosed. Scientists interested in research studies on endometriosis or autoimmune diseases should consider the likelihood of comorbidity when studying these two types of health conditions. Well-designed large prospective cohort studies with confounding control and mediation quantification, as well as genetic and biological studies, are needed to generate further insights into whether endometriosis is a risk factor for, or a consequence of, autoimmune diseases, and whether these two types of disorders share pathophysiological mechanisms even if they arise independently. Such insights may offer opportunities for the development of novel non-hormonal medications such as immuno-modulators or repurposing of existing immunomodulatory therapies for endometriosis.

Functional polymorphism within NUP210 encoding for nucleoporin GP210 is associated with the risk of endometriosis

OBJECTIVE

To investigate whether nucleoporin 210 (GP210, encoded by NUP210 gene) is involved in endometriosis.

DESIGN

Immunohistofluorescence analysis for assessing whether GP210 is expressed in endometrial tissues from patients and controls; genotyping and case-control study for assessing the association between rs354476 within NUP210 and risk of endometriosis; in vitro luciferase assay for assessing the functional activity of rs354476.

SETTING

University.

PATIENT(S)

Histologically diagnosed cases (n = 175) of endometriosis: minimal or mild (stage I-II) in 48 cases (28%), moderate (stage III) in 69 cases (39%), and severe (stage IV) in 58 cases (33%). Controls (n = 557) were female blood donors collected at Meyer Hospital of Florence.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

GP210 tissue expression; genotype distribution and risk of endometriosis; in vitro gene expression measurements.

RESULT(S)

GP210 had positive nuclear immunohistofluorescence staining in endometrial glandular epithelium. Carriers of the variant allele were associated with increased risks: C/T, odds ratio (OR) 1.83, 95% confidence interval (CI) 1.04-3.21; T/T, OR 2.55, 95% CI 1.36-4.80. In vitro, luciferase assay showed that rs354476 is a bona fide target for hsa-miR-125b-5p.

CONCLUSION(S)

Nucleoporin GP210 is involved in endometriosis. Rs354476 polymorphism affects the regulation of NUP210 gene expression by altering the binding with hsa-miR-125b-5p, a microRNA already known as playing an important role for endometriosis. This provides the rationale for the observed increased risk of endometriosis in carriers of the variant allele.

Mixed endometrioid and clear cell carcinoma arising from laparoscopic trocar site endometriosis

Laparoscopic port site endometriosis is less common in abdominal wall endometriosis, and malignant transformation of abdominal wall endometriosis is rare. We reported a case of mixed endometrioid and clear cell carcinoma arising from port site endometriosis. The patient was a 49-year-old woman with a history of laparoscopic excision of ovarian endometrioma. Physical examination revealed a subcutaneous solid tumor around the laparoscopic surgical scar. Imaging showed a suspicious malignancy. She underwent radical marginal resection of the abdominal wall tumor, flap reconstruction of the abdominal wall, hysterectomy, bilateral salpingo-oophorectomy and omental biopsy. Histological examination revealed mixed endometrioid and clear cell carcinoma. Computed tomography scan showed no evidence of recurrence after six cycles of chemotherapy. This is the first case of malignant transformation from laparoscopic trocar site endometriosis.

Desmoid Tumor at the Site of Endometriosis Surgery, Coincident with the Use of Oral Contraceptives

Desmoid tumors, which are often estrogen-dependent, frequently develop in surgical wounds. Here we report the case of 33-year-old woman with a 4-cm solid mass detected in her left adnexal area. She had previously undergone a laparoscopic surgery for endometriosis at age 29 years and had been using a combined oral contraceptive (COC) to prevent recurrence. The mass was diagnosed as a uterine myoma on the basis of ultrasonography and magnetic resonance imaging. Gonadotropin-releasing hormone agonist therapy for 3 months resulted in shrinkage of the tumor. Using a second laparoscopy, we identified a tumor originating from the sigmoid colon. The pathological diagnosis was desmoid tumor. Gynecologists should consider the possibility of desmoid tumor in patients who have been using COCs and undergone previous surgeries.

Retrospective evaluation of pathological results among women with ovarian endometriomas versus teratomas

The coexistence of endometrioma with dermoid cyst of the ovaries is an unusual entity, although they are both common and benign gynecological tumors. The present study aimed to investigate the association between ovarian dermoid cyst (teratoma) and endometrioma. We retrospectively, included 315 women with endometrioma and 172 with ovarian teratoma. Data were collected from medical and pathological reports from two different areas between 1995 and 2018. The mean age of cases with endometrioma was similar (35.8±7.2 years) to patients with ovarian teratoma (34.2±6.8 years). Considering the types of dermoid cysts, the observed proportion of mature type was 168/172 (98%), the immature type was 4/172 (2%) and struma ovarii was14/172 (8.1%) respectively. Endometrioma was significantly more frequent in the left ovary [174/266 (65.4%)] than in the right ovary [92/266 (34.6%)], P<0.001. By contrast, ovarian teratoma were predominant in the right ovary, 98/172 (60.6%), compared to the left side, 56/172 (32.5%), P<0.001. Regarding the size of the masses, we detected an inverse distribution between the two groups. Thirteen women were detected with ovarian teratoma and endometriosis, with 6 cases being in the same ovary. Our results indicate a left lateral predispostion of endometrioma and a right of ovarian teratoma and suggest that the pathogenesis between these conditions is different. The coexistence of endometriosis with dermoid cyst of the ovary, presents a challenge to the physicians and the investigators. Further research is required to establish the relationship between endometriosis and ovarian teratoma.

Influence of early-life factors on the development of endometriosis

Objective: Our aim was to study the association between early-life factors and the development of endometriosis. Methods: This case-control study included 440 women with surgically confirmed endometriosis (cases) and 880 women without endometriosis (controls). Information on early-life factors was ascertained retrospectively by in-person interviews with participants and their mothers. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between endometriosis and maternal and paternal characteristics and foetal and infant exposures were estimated using unconditional logistic regression, adjusting for frequency matching and confounding variables. Results: We observed that women who were not breastfed as infants had twice the risk of endometriosis compared with women who were breastfed (adjusted OR 2.0; 95% CI 1.6, 4.5). Our data suggested an increased endometriosis risk with neonatal vaginal bleeding (adjusted OR 1.9; 95% CI 1.2, 4.3) and paternal smoking (adjusted OR 1.8; 95% CI 1.1, 4.9). Although the CIs included the null hypothesis value, caesarean section (adjusted OR 1.7; 95% CI 1.0, 3.5) and prematurity (adjusted OR 1.4; 95% CI 0.8, 3.7) were probably associated with the incidence of endometriosis. Conclusions: Some early-life factors including breastfeeding, neonatal vaginal bleeding and paternal smoking were associated with subsequent, surgically confirmed endometriosis in this cohort of Chinese women.

Contralateral ovarian endometrioma recurrence after unilateral salpingo-oophorectomy

Background

The recurrence rate after unilateral salpingo-oophorectomy (USO) for unilateral endometrioma has not been reported. We evaluated the rate of and risk factors for endometrioma recurrence after USO.

Methods

In this retrospective observational study, we enrolled 110 women (age, 35–45 years) who underwent laparoscopic USO (n = 50) or cystectomy (n = 60) for unilateral ovarian endometrioma from January 2010 through December 2012. We compared patients’ characteristics between patients who underwent USO and those who underwent cystectomy. We also compared patients with and without an endometrioma recurrence after USO using univariate and multivariate stepwise logistic regression models to identify recurrence risk factors. Endometrioma recurrence was defined as an ovarian cyst (> 2 cm) with features typical of an endometrioma identified by postoperative transvaginal sonography.

Results

Endometrioma recurred in 8 (16%) patients after USO (mean follow-up, 46.0 ± 12.9 months [range, 15–73]). The post-USO cumulative recurrence rates at 12, 24, 36, and 60 months were 8.0, 10.2, 12.7, and 24.7%, respectively (Kaplan-Meier analysis). In logistic regression analysis, a contralateral side adhesion score ≥ 4 was an independent risk factor for endometrioma recurrence after USO (odds ratio, 19.48, 95% confidence interval, 1.59–237.72). The post-USO cumulative recurrence rates at 12, 24, 36, and 57 months were 19.5, 24.1, 31.0, and 54.0%, respectively, in cases with contralateral side adhesion scores ≥4, and 0.0, 0.0, 0.0, and 5.9%, respectively, in cases with scores < 4 (log-rank test, P = 0.0023).

Conclusions

To our knowledge, this is the first report on the recurrence rate and risk factors associated with recurrence after USO. Endometrioma recurrence rates were 24.7% during the first 5 years after USO. The post-USO recurrence rate increased significantly in cases with contralateral side adhesions. Our findings could improve the planning of USO and patient selection for postoperative hormonal therapy.

Downregulated circular RNA hsa_circ_0067301 regulates epithelial-mesenchymal transition in endometriosis via the miR-141/Notch signaling pathway

Endometriosis is a common gynecologic disorder with enigmatic etiopathogenesis and is characterized by tumor-like biological behaviors. Epithelial-mesenchymal transition (EMT) has been recognized as a core mechanism of endometriosis. Recently, circular RNAs (circRNAs) have attracted considerable attention because they play an important role in the progression of cancer. However, little is known about the function of circRNAs in endometriosis. This study is intended to investigate the involvement of circRNAs and microRNAs in the process of EMT in ovarian endometriosis in vitro. We found that relative RNA levels of hsa_circ_0067301 and miR-141-5p were significantly reduced in ectopic endometrium when compared to control endometrium. Hsa_circ_0067301 knockdown could promote the proliferation and migration in Ishikawa and End1/E6E7 cells, concomitant with increased the relative protein expression against Notch-1, Hes-1, N-cadherin, and vimentin but reduced expression of E-cadherin. After co-transfection with the miR-141-5p inhibitor, the miR-141-5p that competes for binding to hsa_circ_0067301 was reduced, reversed EMT and partially restored the expression of Notch-1 and Hes-1. Results demonstrate the hsa_circ_0067301/miR-141-5p/Notch-1 axis plays an important regulatory role in the process of EMT in endometriosis. The study highlighted the importance of circRNAs in ovarian endometriosis and provided unique insights into the molecular basis concerning the pathogenesis of endometriosis.

Defining the genetic profile of endometriosis

Endometriosis is a pathological condition which has been extensively studied, since its pathophysiology stems from a broad spectrum of environmental influences and genetic factors. Familial studies aim at defining inheritance trends, while linkage analysis studies focus on the identification of genetic sites related to endometriosis susceptibility. Genetic association studies take into account candidate genes and single nucleotide polymorphisms, and hence target at unraveling the association between disease severity and genetic variation. The common goal of various types of studies is, through genetic mapping methods, the timely identification of therapeutic strategies for disease symptoms, including pelvic pain and infertility, as well as efficient counselling. While genome-wide association studies (GWAS) play a primary role in depicting genetic contributions to disease development, they entail a certain bias as regards the case-control nature of their design and the reproducibility of the results. Nevertheless, genetic-oriented studies and the implementation of the results through clinical tests, hold a considerable advantage in proper disease management. In this review article, we present information about gene-gene and gene-environment interactions involved in endometriosis and discuss the effectiveness of GWAS in identitying novel potential therapeutic targets in an attempt to develop novel therapeutic strategies for a better management and treatment of patients with endometriosis.

Mitochondrial DNA deletions accurately detect endometriosis in symptomatic females of child-bearing age

Aim: Accurate noninvasive diagnostic aids for endometriosis are needed. We evaluated mitochondrial DNA deletions as potential biomarkers for endometriosis. Methods: The diagnostic accuracy of deletions was evaluated by quantitative polymerase chain reaction (QPCR) using well-characterized clinical specimens from all subtypes and stages of endometriosis in a case–control format (n = 182). Results: Deletions (1.2 and 3.7 kb) detected in blood differentiated between endometriosis and controls (area under the curve [AUC] 0.71–0.90). Differences in deletion levels were statistically significant (p < 0.05) for all disease subtypes and stages. Neither deletion was correlated with patient or specimen age or hormone status. The 1.2 kb deletion was not correlated with menstrual stage; the 3.7 kb deletion was significantly correlated between two of the groups. Conclusion: Biomarkers of the mitochondrial genome, including the deletions described here, offer a promising and largely unexplored avenue in the pursuit of diagnostic markers for endometriosis that can be effectively translated to clinical application.

Effects of psychological care in patients with endometriosis: A systematic review protocol

BACKGROUND

This systematic review will be proposed for investigating the effects of psychological care (PC) in patients with endometriosis.

METHODS

We will search the following 7 electronic databases from inception to the present: MEDLINE, EMBASE, SinoMed, Web of Science, Cochrane Library, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. We will include randomized controlled trials for evaluating the effects of PC in patients with endometriosis. Cochrane risk of bias tool will be used to evaluate the methodological quality for each included study. Two authors will independently carry out the study selection, data extraction, and methodological quality evaluation. Any disagreements will be solved by a third author through discussion.

RESULTS

This proposed systematic review will use high-quality evidence-based medicine to evaluate the efficacy and safety of PC for endometriosis. The primary outcomes include depression and anxiety. The secondary outcomes consist of pain intensity, health-related quality of life, and adverse events.

CONCLUSION

The findings of this study will provide convincing evidence to determine whether PC therapy is an effective and safe intervention for patients with endometriosis.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019123292.

Neuropeptides Substance P and Calcitonin Gene Related Peptide Accelerate the Development and Fibrogenesis of Endometriosis

Endometriotic lesions are known to be hyperinnervated, especially in lesions of deep endometriosis (DE), which are frequently in close proximity to various nerve plexuses. DE lesions typically have higher fibromuscular content than that of ovarian endometriomas (OE) lesions, but the underlying reason remains elusive. Aside from their traditional role of pain transduction, however, whether or not sensory nerves play any role in the development of endometriosis is unclear. Here, we show that, thorough their respective receptors neurokinin receptor 1 (NK1R), calcitonin receptor like receptor (CRLR), and receptor activity modifying protein 1 (RAMP-1), neuropeptides substance P (SP) and calcitonin gene related peptide (CGRP) induce epithelial-mesenchymal transition (EMT), fibroblast-to-myofibroblast transdifferentiation (FMT) and further turn stromal cells into smooth muscle cells (SMCs) in endometriotic lesions, resulting ultimately in fibrosis. We show that SP and CGRP, or the rat dorsal root ganglia (DRG) supernatant, through the induction of NK1R and CGRP/CRLR/RAMP-1 signaling pathways, promoted EMT, FMT and SMM in endometriosis, resulting in increased migratory and invasive propensity, cell contractility, production of collagen, and eventually to fibrosis. Neutralization of NK1R and/or CGRP/CRLR/RAMP-1 abrogated these processes. Extended exposure of endometriotic stromal cells to SP and/or CGRP or the DRG supernatant induced increased expression of α-SMA, desmin, oxytocin receptor, and smooth muscle myosin heavy-chain. Finally, we show that DE lesions had significantly higher nerve fiber density, increased staining levels of α-SMA, NK1R, CRLR, and RAMP-1, concomitant with higher lesional fibrotic content than that of OE lesions. The extent of lesional fibrosis correlated positively with the staining levels of NK1R, CRLR, and RAMP-1, as well as the nerve fiber density in lesions. Thus, this study provides another piece of evidence that sensory nerves play an important role in promoting the development and fibrogenesis of endometriosis. It explains as why DE frequently have higher fibromuscular content than that of OE, highlights the importance of lesional microenvironment in shaping the lesional fate, gives more credence to the idea that ectopic endometrium is fundamentally wounds that go through repeated tissue injury and repair, and should shed much needed light into the pathophysiology of endometriosis.

IFITM1 is a Novel, Highly Sensitive Marker for Endometriotic Stromal Cells in Ovarian and Extragenital Endometriosis

When the presence of endometriotic lesions are not evident by hematoxylin and eosin staining, CD10 is used to highlight and confirm the presence of endometriotic stroma. However, CD10 is not specific only to the endometrial stroma but is also expressed in many other cells. Recently, interferon-inducible transmembrane protein 1 (IFITM1) was reported as a highly specific immunohistochemical marker of normal endometrial stroma and endometrial stromal neoplasm. In this study, we examined the expression of IFITM1 and CD10 in 18 cases of ovarian endometriosis and 44 cases of extragenital endometriosis. Among the 62 patients, 62 (100.0%) were positive for IFITM1 and 60 (96.8%) for CD10, and CD10 was negative in 2 cases that were positive for IFITM1. Additionally, we found that IFITM1 sensitivity was unaffected by the presence or absence of hormonal therapy. To the best of our knowledge, this represents the first demonstration of IFITM1 as a highly sensitive stromal marker of ovarian and extragenital endometriosis.

Sphingosine 1 Phosphate (S1P) Increased IL-6 Expression and Cell Growth in Endometriotic Cells

OBJECTS

There is growing evidence that sphingosine 1-phosphate (S1P) is involved in inflammatory diseases. As endometriosis is known as an inflammatory disease, we investigated the role of S1P system in the development of endometriosis.

METHODS

The expression of sphingosine kinase (SphK) 1 in endometriosis lesions was examined by immunohistochemistry. The cystic fluid of ovarian cysts/tumors were obtained to measure S1P concentrations. Endometriotic stromal cells (ESC) derived from endometrioma were used for in vitro experiments.

RESULTS

Sphingosine kinase 1 was detected in epithelium and stromal cells of endometriotic lesions. The mean S1P concentration in the cystic fluid of endometriomas was higher than that in nonendometriomas significantly (98.2 nM vs less than 1.5 nM, P < .01). Interleukin-1β (IL-1β) or transforming growth factor-β exhibited 2.7-fold and 11.5-fold increase in SphK1 messenger RNA (mRNA) expression in ESC, respectively (P < .01). Higher dose of S1P (125nM) increased the cell number of ESC by 20%, and low dose of S1P (1.25 nM and 12.5 nM) induced IL-6 mRNA production and IL-6 secretion by ESC dose-dependently. JTE013, an antagonist for S1PR2, partially suppressed IL-6 induction by S1P (P < .05). JTE013 and VPC23019, an antagonist for S1PR1 and S1PR3, suppressed the ESC proliferation induced by S1P.

CONCLUSION

The present study for the first time proved that the SphK-S1P-S1PR axis play a role of accelerating inflammation and growth of endometriotic cells.

Endometriosis-associated ovarian cancer: What have we learned so far?

Endometriosis is defined as the presence of ectopic endometrial tissue outside of the uterine cavity, most commonly in the ovaries and peritoneum. It is a complex disease that is influenced by multiple factors. It is also a common gynecological disorder and affects approximately 10-15% of all women of reproductive age. Recent molecular and pathological studies indicate that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), particularly endometrioid and clear cell ovarian cancers. Although histological and epidemiological studies have demonstrated that endometriosis has a malignant potential, the molecular mechanism that underlies the malignant transformation of endometriosis is still controversial, and the precise mechanism of carcinogenesis must be fully elucidated. Currently, the development and improvement of a new sequencing technology, next-generation sequencing (NGS), has been increasingly relevant in cancer genomics research. Recently, NGS has also been utilized in clinical oncology to advance the personalized treatment of cancer. In addition, the sensitivity, speed, and cost make NGS a highly attractive platform compared to other sequencing modalities. For this reason, NGS may lead to the identification of driver mutations and underlying pathways associated with EAOC. Here, we present an overview of the molecular pathways that have led to the current opinions on the relationship between endometriosis and ovarian cancer.

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

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

Role of a natural integrator based on lipoic acid, palmitoiletanolamide and myrrh in the treatment of chronic pelvic pain and endometriosis

BACKGROUND

Dysmenorrhea and chronic pelvic pain occur in a significantly higher percentage in women with endometriosis; this benign condition has an incidence ranging from 5% to 10% in the general population, while 35% to 50% of infertile women are affected. Treatment of the symptoms demands integrated approaches with the use of anti-inflammatory substances or drugs and lifestyle changes, including attention to diet. The use of traditional anti-inflammatory drugs over the long term is not very successful because of the fear of side effects so they are almost always used with a short-term formula of 7-10 days when the woman's general condition becomes difficult to bear. In recent years, particular attention has been paid to natural substances with recognized anti-inflammatory activities that, associated with one another, are able to synergize individual actions. A nutraceutical containing substances capable of fighting chronic pelvic pain has recently been put on the market. The possible action mechanism derives from a synergy of action between alpha-lipoic acid, palmitoiletanolamide (PEA) and myrrh (Pelvinox, Laborest Italia srl, Nerviano, Milan, Italy), whose action is so effective that it is able to replace the use of anti-inflammatory drugs. The aim of the study was to evaluate the effect of these active ingredients in women with endometriosis and chronic pelvic pain.

METHODS

This multicenter study saw the recruitment of 60 women (divided between the three centers participating in the study, Siena, Bologna and Udine) aged between 20 and 39 suffering from endometriosis (ovarian) and chronic pelvic pain. All the women took one nutraceutical (Pelvinox) at a dose of two tablets per day for 6 months.

RESULTS

The results showed a significant reduction in pain symptoms as regards dyspareunia, dysmenorrhea and chronic pelvic pain, while there was no change in the mean diameter of the endometriosis cysts.

CONCLUSIONS

In light of the above, it is believed that substances such as alpha-lipoic acid, PEA and myrrh may play a very important role in this type of patient in the treatment of individual symptoms.

Female subfertility

Subfertility is common and affects one in six couples, half of whom lack an explanation for their delay in conceiving. Developments in the diagnosis and treatment of subfertility over the past 50 years have been truly remarkable. Indeed, current generations of couples with subfertility are more fortunate than previous generations, as they have many more opportunities to become parents. The timely access to effective treatment for subfertility is important as many couples have a narrow window of opportunity before the age-related effects of subfertility limit the likelihood of success. Assisted reproduction can overcome the barriers to fertility caused by tubal disease and low sperm count, but little progress has been made in reducing the effect of increasing age on ovarian function. The next 5-10 years will likely see further increases in birth rates in women with subfertility, a greater awareness of lifestyle factors and a possible refinement of current assisted reproduction techniques and the development of new ones. Such progress will bring challenging questions regarding the potential benefits and harms of treatments involving germ cell manipulation, artificial gametes, genetic screening of embryos and gene editing of embryos. We hope to see a major increase in fertility awareness, access to safe and cost-effective fertility care in low-income countries and a reduction in the current disparity of access to fertility care.

Regulation of Inflammation Pathways and Inflammasome by Sex Steroid Hormones in Endometriosis

Endometriosis is a gynecological disorder characterized by the growth of endometrial tissue (glands and stroma) outside the uterus, mainly in the peritoneal cavity, ovaries, and intestines. This condition shows estrogen dependency and progesterone resistance, and it has been associated with chronic inflammation, severe pain, and infertility, which negatively affect the quality of life in reproductive women. The molecular mechanisms involved in the pathogenesis of endometriosis are not completely understood; however, inflammation plays a key role in the pathophysiology of the disease, mainly by altering the function of immune cells (macrophages, natural killer, and T cells) and increasing levels of pro-inflammatory mediators in the peritoneal cavity, endometrium, and blood. These immune alterations inhibit apoptotic pathways and promote adhesion and proliferation of endometriotic cells, as well as angiogenesis and neurogenesis in endometriotic lesions. It has been demonstrated that hormonal alterations in endometriosis are related to the inflammatory unbalance in this disease. Particularly, steroid hormones (mainly estradiol) promote the expression and release of pro-inflammatory factors. Excessive inflammation in endometriosis contributes to changes of hormonal regulation by modulating sex steroid receptors expression and increasing aromatase activity. In addition, dysregulation of the inflammasome pathway, mediated by an alteration of cellular responses to steroid hormones, participates in disease progression through preventing cell death, promoting adhesion, invasion, and cell proliferation. Furthermore, inflammation is involved in endometriosis-associated infertility, which alters endometrium receptivity by impairing biochemical responses and decidualization. The purpose of this review is to present current research about the role of inflammasome in the pathogenesis of endometriosis as well as the molecular role of sex hormones in the inflammatory responses in endometriosis.

Differentially-Expressed miRNAs in Ectopic Stromal Cells Contribute to Endometriosis Development: The Plausible Role of miR-139-5p and miR-375

microRNA (miRNA) expression level alterations between endometrial tissue and endometriotic lesions indicate their involvement in endometriosis pathogenesis. However, as both endometrium and endometriotic lesions consist of different cell types in various proportions, it is not clear which cells contribute to variability in miRNA levels and the overall knowledge about cell-type specific miRNA expression in ectopic cells is scarce. Therefore, we utilized fluorescence-activated cell sorting to isolate endometrial stromal cells from paired endometrial and endometrioma biopsies and combined it with high-throughput sequencing to determine miRNA alterations in endometriotic stroma. The analysis revealed 149 abnormally expressed miRNAs in endometriotic lesions, including extensive upregulation of miR-139-5p and downregulation of miR-375 compared to eutopic cells. miRNA transfection experiments in the endometrial stromal cell line ST-T1b showed that the overexpression of miR-139-5p resulted in the downregulation of homeobox A9 (HOXA9) and HOXA10 expression, whereas the endothelin 1 (EDN1) gene was regulated by miR-375. The results of this study provide further insights into the complex molecular mechanisms involved in endometriosis pathogenesis and demonstrate the necessity for cell-type-specific analysis of ectopic tissues to understand the interactions between different cell populations in disease onset and progression.

Expression of Nerve Injury-Induced Protein1 (Ninj1) in Endometriosis

OBJECTIVE

The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

BACKGROUND

Nerve injury-induced protein 1 (Ninj1) is a molecule originally identified in dorsal root ganglion neurons and Schwann cells after nerve injury and promotes neurite outgrowth. The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

MATERIALS AND METHODS

Tissues were obtained with consent from patients diagnosed with ovarian endometrioma (n = 15 in total), peritoneal endometriosis (n = 5), adenomyosis (n = 5), and other gynecological disorders (n = 5, control) during surgery. Immunohistochemistry was conducted in order to detect Ninj1 protein expression in the lesion of endometriosis, adenomyosis, and eutopic endometrium. Nerve fibers in the ovarian endometrioma were detected by positive staining of PGP-9.5. To evaluate the effects of IL-1β on Ninj1 gene expression in endometriosis, ESCs isolated from ovarian endometrioma (n = 5) were treated with IL-1β (5 ng/mL) for 3 or 6 hours. Messenger RNA (mRNA) expression for Ninj1 was examined using quantitative RT-PCR.

RESULTS

The Ninj1 protein was expressed by ovarian endometrioma, peritoneal endometriotic, and adenomyotic tissue. Nerve fibers were found in the areas of positive staining for Ninj1 in ovarian endometrioma. IL-1β, an indicator of inflammation in endometriosis, significantly increased Ninj1 mRNA expression by ESC.

CONCLUSION

Our study demonstrates that Ninj1 is expressed in endometriosis and adenomyosis and is induced by the inflammatory stimuli. Given the neurogenetic property of Ninj1, our results imply that Ninj1, induced by inflammation in endometriosis lesion, may contribute to the pathogenesis of pain symptoms characteristic of endometriosis.

Effects of human recombinant type I IFNs (IFN-α2b and IFN-β1a) on growth and migration of primary endometrial stromal cells from women with deeply infiltrating endometriosis: A preliminary study

OBJECTIVE(S)

Endometriosis is a major cause of infertility and disability for women, caused by the presence of inflammatory endometrial implants in extrauterine locations. Among the constituents involved in the immune response during the development of endometriosis, several chemokines, including interferons (IFNs) may have a role in the pathogenesis of this disease. The aim of this preliminary study was to investigate the anti-proliferative and anti-migratory activities of type I IFNs (IFN-α2b and IFN-β1a) in primary endometrial stromal cells (ESCs) isolated from women with deeply infiltrating endometriosis (DIE).

STUDY DESIGN

The study subjects included 7 women ranged in the age from 27 to 37 years with diagnosis of DIE (Stage III and IV). Collected primary ESC monolayers, isolated from endometriotic nodules, were incubated with various concentrations (from 1 to 1000 IU/ml) of IFN-α2b or IFN-β1a.

RESULT(S)

IFN-β1a had a significantly higher activity in hampering the proliferation of cells compared to IFN-α2b. This effect could be related to the induction of apoptosis and cell cycle arrest in S phase, observed in ESCs during incubation with IFN-β1a. Moreover, IFN-β1a was more potent than IFN-α2b in inhibiting migration and EGF-induced ERK activity of primary ESCs.

CONCLUSION(S)

The inhibitory in vitro effect on ESC proliferation and migration of IFN-β1a was much more potent than IFN-α2b. These preliminary data offer the rationale for future preclinical and clinical trials using IFN-β1a as a new tool for the therapy and tertiary prevention in patients with DIE.

Vitamin D and Endometrium: A Systematic Review of a Neglected Area of Research

Growing evidence supports a role of vitamin D (VD) in reproductive health. Vitamin D receptor (VDR) is expressed in the ovary, endometrium, and myometrium. The biological actions of VD in fertility and reproductive tissues have been investigated but mainly using animal models. Conversely, the molecular data addressing the mechanisms underlying VD action in the physiologic endometrium and in endometrial pathologies are still scant. Levels of VDR expression according to the menstrual cycle are yet to be definitively clarified, possibly being lower in the proliferative compared to the secretory phase and in mid-secretory compared to early secretory phase. Endometrial tissue also expresses the enzymes involved in the metabolism of VD. The potential anti-proliferative and anti-inflammatory effects of VD for the treatment of endometriosis have been investigated in recent years. Treatment of ectopic endometrial cells with 1,25(OH)₂D₃ could significantly reduce cytokine-mediated inflammatory responses. An alteration of VD metabolism in terms of increased 24-hydroxylase mRNA and protein expression has been demonstrated in endometrial cancer, albeit not consistently. The effect of the active form of the vitamin as an anti-proliferative, pro-apoptotic, anti-inflammatory, and differentiation-inducing agent has been demonstrated in various endometrial cancer cell lines.