Recurrence of endometriosis: risk factors, mechanisms and biomarkers

MCP-1 exerts the inflammatory response via ILK activation during endometriosis pathogenesis

AIMS

MCP-1 has been shown to be elevated in endometriosis. ILK functions in several cellular events and interacts with MCP-1-signaling. In the current study, we evaluated the role of MCP-1-ILK signaling in human endometriotic cell's (Hs832(C).TCs) potential for colonization, invasion, adhesion, etc. and differentiation of macrophage along with inflammation in an endometriosis mouse model.

MATERIALS AND METHODS

A mouse model of endometriosis with elevated levels of MCP-1 was developed by injecting MCP-1. We examined the migration, adhesion, colonization and invasion of Hs832(C).TCs in response to MCP-1-ILK signaling. We also examined the differentiation of THP-1 cells to macrophage in response to MCP-1-ILK signaling.

KEY FINDINGS

We observed that MCP-1 increased Ser246 phosphorylation of ILK in Hs832(C).TCs and enhanced the migration, adhesion, colonization, and invasion of Hs832(C).TCs. In the mouse model of endometriosis, we found elevated chemokines (CCL-11, CCL-22 and CXCL13) levels. An increased level of MCP-1 mediated ILK activation, leading to increased inflammatory reaction and infiltration of residential and circulatory macrophages, and monocyte differentiation, but suppressed the anti-inflammatory reaction. The inhibitor (CPD22) of ILK reversed the MCP-1-mediated action by restoring Hs832(C).TCs and THP-1 phenotype. ILK inhibition in a mouse model of endometriosis reduced the effects of MCP-1 mediated pro-inflammatory cytokines, but increased anti-inflammatory response along with T-regulatory and T-helper cell restoration.

SIGNIFICANCE

Targeting ILK restores MCP-1 milieu in the peritoneal cavity and endometrial tissues, reduces the inflammatory response, improves the T-regulatory and T-helper cells in the endometriosis mouse model and decreases the migration, adhesion, colonization and invasion of endometriotic cells.

Linzagolix therapy versus a placebo in patients with endometriosis-associated pain: a prospective, randomized, double-blind, Phase 3 study (EDELWEISS 3)

STUDY QUESTION

Does linzagolix administered orally once daily for up to 3 months at a dose of 75 mg alone or 200 mg in combination with add-back therapy (ABT) (1.0 mg estradiol; 0.5 mg norethindrone acetate, also known as norethisterone acetate [NETA]) demonstrate better efficacy than placebo in the management of endometriosis-related dysmenorrhea and non-menstrual pelvic pain?

SUMMARY ANSWER

Combining 200 mg linzagolix with ABT was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain at 3 months of therapy, while a daily dose of 75 mg linzagolix yielded a significant decrease only in dysmenorrhea at 3 months.

WHAT IS KNOWN ALREADY?

A previously published Phase 2, dose-finding study reported that at a dose of 200 mg daily, linzagolix promotes full suppression of estradiol secretion to serum levels below 20 pg/ml and noted that the addition of ABT may be needed to manage hypoestrogenic side effects. At lower doses (75 mg and 100 mg/day), linzagolix maintains estradiol values within the target range of 20-60 pg/ml, which could be ideal to alleviate symptoms linked to endometriosis.

STUDY DESIGN, SIZE, DURATION

EDELWEISS 3 was a multicenter, prospective, randomized, placebo-controlled, double-blind, double-dummy Phase 3 study to evaluate the safety and efficacy of linzagolix for the treatment of moderate-to-severe endometriosis-associated pain. Treatment was administered orally once daily for up to 6 months.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the EDELWEISS 3 trial, 486 subjects with moderate-to-severe endometriosis-associated pain were randomized at a 1:1:1 ratio to one of the three study groups: placebo, 75 mg linzagolix alone or 200 mg linzagolix in association with ABT. Pain was measured daily on a verbal rating scale and recorded in an electronic diary.

MAIN RESULTS AND THE ROLE OF CHANCE

At 3 months, the daily 200 mg linzagolix dose with ABT met the primary efficacy objective, showing clinically meaningful and statistically significant reductions in dysmenorrhea and non-menstrual pelvic pain, with stable or decreased use of analgesics. The proportion of responders for dysmenorrhea in the 200 mg linzagolix with ABT group was 72.9% compared with 23.5% in the placebo group (P < 0.001), while the rates of responders for non-menstrual pelvic pain were 47.3% and 30.9% (P = 0.007), respectively. The 75 mg linzagolix daily dose demonstrated a clinically meaningful and statistically significant reduction in dysmenorrhea versus placebo at 3 months. The proportion of responders for dysmenorrhea in the 75 mg linzagolix group was 44.0% compared with 23.5% in the placebo group (P < 0.001). Although the 75 mg dose showed a trend toward reduction in non-menstrual pelvic pain at 3 months relative to the placebo, it was not statistically significant (P = 0.279). Significant improvements in dyschezia and overall pelvic pain were observed in both linzagolix groups when compared to placebo. Small improvements in dyspareunia scores were observed in both linzagolix groups but they were not significant. In both groups, hypoestrogenic effects were mild, with low rates of hot flushes and bone density loss of <1%. A daily dose of 200 mg linzagolix with ABT or 75 mg linzagolix alone was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain also at 6 months of therapy.

LIMITATIONS, REASONS FOR CAUTION

Efficacy was compared between linzagolix groups and placebo; however, it would be useful to have results from comparative studies with estro-progestogens or progestogens. It will be important to ascertain whether gonadotropin-releasing hormone antagonists have significant benefits over traditional first-line medications.

WIDER IMPLICATIONS OF THE FINDINGS

Linzagolix administered orally once daily at a dose of 200 mg in combination with add-back therapy (ABT) demonstrated better efficacy and safety than placebo in the management of moderate-to-severe endometriosis-associated pain. The quality of life was improved and the risks of bone loss and vasomotor symptoms were minimized due to the ABT. The 75 mg dose alone could be suitable for chronic treatment of endometriosis-associated pain without the need for concomitant hormonal ABT, but further research is needed to confirm this. If confirmed, it would offer a viable option for women who do not want to wish to have ABT or for whom it is contraindicated.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for the EDELWEISS 3 study was provided by ObsEva (Geneva, Switzerland). Analysis of data and manuscript writing were partially supported by ObsEva (Geneva, Switzerland), Theramex (London, UK) and Kissei (Japan) and grant 5/4/150/5 was awarded to M.-M.D. by FNRS. J.D. was a member of the scientific advisory board of ObsEva until August 2022, a member of the scientific advisory board of PregLem, and received personal fees from Gedeon Richter, ObsEva and Theramex. J.D. received consulting fees, speakers' fees, and travel support from Gedeon Richter, Obseva and Theramex, which was paid to their institution. C.B. has received fees from Theramex, Gedeon Richter, and Myovant, and travel support from Gedeon Richter-all funds went to the University of Oxford. He was a member of the data monitoring board supervising the current study, and served at an advisory board for endometriosis studies of Myovant. H.T. has received grants from Abbvie and was past president of ASRM. F.C.H. has received fees from Gedeon Richter and Theramex. O.D. received fees for lectures from Gedeon Richter and ObsEva and research grants for clinical studies from Preglem and ObsEva independent from the current study. A.H. has received grants from NIHR, UKRI, CSO, Wellbeing of Women, and Roche Diagnostics; he has received fees from Theramex. A.H.'s institution has received honoraria for consultancy from Roche Diagnostics, Gesynta, and Joii. M.P. has nothing to declare. F.P. has received fees from Theramex. S.P.R. has been a member of the scientific advisory board of Gedeon Richter and received fees from Gedeon Richter. A.P. and M.B. are employees of Theramex. E.B. was an employee of ObsEva, sponsor chair of the data monitoring board supervising the current study, and has been working as a consultant for Theramex since December 2022; she owns stock options in ObsEva. M.-M.D. has received fees and travel support from Gedeon Richter and Theramex.

TRIAL REGISTRATION NUMBER

NCT03992846.

TRIAL REGISTRATION DATE

20 June 2019.

DATE OF FIRST PATIENT’S ENROLLMENT

13 June 2019.

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

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

Postoperative Imaging of Endometriosis

Endometriosis is a highly prevalent disease that affects 10%-15% of women of reproductive age worldwide and is mainly associated with chronic pelvic pain and infertility. With the widespread use of imaging for the diagnosis and monitoring of endometriosis, combined with the ability of surgery to eradicate the disease and address infertility, there has been a significant increase in recent years in imaging examinations for postoperative evaluation of endometriosis. US and MRI are used not only to help diagnose and map endometriosis but also to evaluate refractory symptoms, residual lesions, and complications at posttreatment assessment. Knowledge of surgical techniques and recognition of expected postoperative imaging findings are crucial to differentiate postoperative changes from residual disease and/or recurrence. The authors discuss imaging aspects of postoperative endometriosis, with an emphasis on the imaging approach, comprehension of surgical techniques, recognition of the expected findings, possible complications, and analysis of residual disease or recurrence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by VanBuren in this issue. The slide presentation from the RSNA Annual Meeting is available for this article.

Distinct molecular targets of ProEGCG from EGCG and superior inhibition of angiogenesis signaling pathways for treatment of endometriosis

Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus. Angiogenesis is a major pathophysiology in endometriosis. Our previous studies have demonstrated that the prodrug of epigallocatechin gallate (ProEGCG) exhibits superior anti-endometriotic and anti-angiogenic effects compared to epigallocatechin gallate (EGCG). However, their direct binding targets and underlying mechanisms for the differential effects remain unknown. In this study, we demonstrated that oral ProEGCG can be effective in preventing and treating endometriosis. Additionally, 1D and 2D Proteome Integral Solubility Alteration assay-based chemical proteomics identified metadherin (MTDH) and PX domain containing serine/threonine kinase-like (PXK) as novel binding targets of EGCG and ProEGCG, respectively. Computational simulation and BioLayer interferometry were used to confirm their binding affinity. Our results showed that MTDH-EGCG inhibited protein kinase B (Akt)-mediated angiogenesis, while PXK-ProEGCG inhibited epidermal growth factor (EGF)-mediated angiogenesis via the EGF/hypoxia-inducible factor (HIF-1a)/vascular endothelial growth factor (VEGF) pathway. In vitro and in vivo knockdown assays and microvascular network imaging further confirmed the involvement of these signaling pathways. Moreover, our study demonstrated that ProEGCG has superior therapeutic effects than EGCG by targeting distinct signal transduction pathways and may act as a novel antiangiogenic therapy for endometriosis.

Treatment after endometrioma recurrence: a narrative review

INTRODUCTION

Ovarian endometrioma is a common subtype of endometriosis with a prevalence between 17 and 44%. The reported average recurrence of endometrioma after surgical management is 21.5% after 2 years and 40-50% after 5 years. The aim of this narrative review was to summarize the existing literature focusing on treatment options after endometrioma recurrence in order to provide an evidence-based approach for the clinical practice.

EVIDENCE ACQUISITION

Three electronic databases (MEDLINE, EMBASE and Cochrane) were searched until September 2022 for eligible studies.

EVIDENCE SYNTHESIS

The available studies showed that repeated surgery has a negative impact on ovarian function, without improving the fertility outcomes. Transvaginal aspiration as an alternative option for surgery has a high rate of recurrence, which varies from 8.20 to 43.5% depending on the technique used and on the study population. Pregnancy related outcomes were similar between transvaginal aspiration groups and no intervention groups in patients with endometrioma recurrence. Regarding medical treatments, only four studies were found, showing that progestins reduce the pain and the diameter of the ovarian cyst.

CONCLUSIONS

Recurrent endometrioma is a challenging condition which could be encountered during the care of women with endometriosis. The decision about the treatment-strategy has to be individualized considering family planning status, age, ovarian reserve and transvaginal ultrasound findings. Well-designed randomized clinical trials are needed to export safer conclusions about the most appropriate treatment in each specific condition after endometrioma recurrence.

Risk factors for recurrent endometriosis after conservative surgery in a quaternary care center in southern Thailand

OBJECTIVES

To determine the 2-year recurrence rate of endometriosis after conservative surgery and the risk factors for recurrence.

METHODS

This study retrospectively analyzed women with endometriosis who underwent conservative surgery and had at least a 2-year follow-up at a quaternary care hospital in southern Thailand from January 2000 to December 2019. Recurrent endometriosis was defined as either presence of endometrioma with a diameter ≥ 2 cm for more than three consecutive menstrual cycles or relapse of pelvic pain with the same or higher visual analog scale (VAS) score as before surgery. Multivariate logistic regression analysis was used to identify the risk factors for recurrence.

RESULTS

The median (interquartile range [IQR]) age was 34 (29, 38) years in 362 cases and nearly three-quarters (74.2%) were nulliparous. Cyclic pain was the most common clinical presentation (48.9%) and the median (IQR) VAS score of pelvic pain was 6 (5, 9). Ovarian cystectomy was the most common procedure (68.1%). The 2-year recurrent endometriosis rate after conservative surgery was 23.2%, and the overall recurrence rate was 56.4%. The risk factors of recurrence were preoperative moderate to severe pelvic pain (adjusted odds ratio [aOR] 1.93; 95% confidence interval [CI], 1.12-3.34; p = 0.017), adhesiolysis/ablation/ovarian cystectomy without unilateral oophorectomy (aOR 2.71; 95% CI, 1.40-5.23; p = 0.002), and duration of postoperative hormonal treatment < 24 months (aOR 10.58; 95% CI, 5.47-20.47; p < 0.001).

CONCLUSION

The 2-year recurrence rate after conservative surgery for endometriosis was 23.2%. Preoperative moderate to severe pelvic pain, procedures except unilateral oophorectomy, and postoperative hormonal treatment < 24 months were risk factors for recurrence.

Lipoxin A4 depresses inflammation and promotes autophagy via AhR/mTOR/AKT pathway to suppress endometriosis

BACKGROUND

Endometriosis is a benign gynecological disease with the feature of estrogen dependence and inflammation. The function of autophagy and the correlation with inflammation were not yet revealed.

METHODS

Autophagosomes were detected by transmission electron microscopy. Gene Expression Omnibus (GEO) database was referred to analyze the expression of autophagy-related genes. Quantification of mRNA and protein expression was examined by qRT-PCR and Western Blot. Immunohistochemistry was performed to explore the expression of proteins in tissues. The mouse model of endometriosis was performed to analyze the autophagic activity and effect of LXA4.

RESULTS

The expression of autophagy-related genes in endometriotic lesions were unusually changed. The number of autophagosomes and LC3B-II expression was diminished, and p62 was increased in ectopic lesions from both patients and mice. Interleukin 1β (IL1β) attenuated the expression of LC3B and promoted the level p62. The autophagy activator MG-132 upregulated the expression of LC3B and reduced IL1β, IL6, and p62. LXA4 reversed the inhibitory effect of IL1β on the expression of LC3B and p62, and blocking the receptor of LXA4 AhR (aryl hydrocarbon receptor) resulted in the incapacitation of LXA4 to influence the effect of IL1β. LXA4 depressed the phosphorylation of AKT and mTOR to against IL1β, and blocking AhR negatively regulated the effect of LXA4 on AKT/mTOR pathway. LXA4 reduced the ectopic lesions and the expression of IL1β and p62, but enhanced LC3B-II in endometriotic mouse models.

CONCLUSION

In endometriosis, increased inflammation of ectopic lesions prominently depresses autophagy. LXA4 could regulate autophagy by suppressing inflammatory response through AhR/AKT/mTOR pathway.

Health-related quality of life of women with endometriosis: An Attachment-Diathesis Model of Chronic Pain perspective

Endometriosis is a common gynecological disorder that occurs in women of reproductive age, and negatively affects women's quality of life. We tested 'Attachment-Diathesis Model of Chronic Pain' in a sample of Turkish women with endometriosis by analyzing the paths among attachment styles, pain catastrophizing, coping strategies, and health-related quality of life (HRQoL). Attachment anxiety was related to using less problem-focused coping and seeking more social support, while attachment avoidance was associated with seeking less social support as a coping strategy. Moreover, attachment anxiety and higher pain catastrophizing were related to a worse HRQoL. Finally, problem-focused coping strategy mediated the relation between attachment anxiety and HRQoL, meaning that by employing less problem-focused coping strategies, anxiously attached women experienced a poorer HRQoL. In light of our findings, psychologists may develop intervention techniques that question attachment patterns, pain perception, and coping strategies in clients diagnosed with endometriosis.

Does endometriosis increase the risks of endometrial hyperplasia and endometrial cancer?

OBJECTIVE

The risk of developing endometrial hyperplasia after diagnosis of endometriosis has not been determined. Moreover, the risk of endometrial cancer associated with endometriosis is unclear. This nationwide population-based study investigated the associations of endometrial hyperplasia and endometrial cancer with endometriosis, after adjusting for covariates.

METHODS

This population-based observational study analyzed data from the Korean National Health Insurance (NHI) database, including 147,869 women who were diagnosed with endometriosis from 2002 to 2017, with each patient matched to 20 control women without endometriosis. Cox proportional hazard regression analyses were performed to estimate the hazard ratios (HRs) of endometrial hyperplasia, endometrial cancer, and mortality from endometrial cancer.

RESULTS

Among three million women in this population, 16,377 women were diagnosed with endometrial hyperplasia, and 1795 women were diagnosed with endometrial cancer over 19,931,794 person-years of follow-up. Women with endometriosis were at significantly higher risks of endometrial hyperplasia (adjusted hazard ratio [aHR] 1.85, 95% confidence interval [CI] 1.75-1.95), and endometrial cancer (aHR 1.35, 95% CI 1.12-1.63) were compared with control women after adjustment for covariates. A diagnosis of endometriosis did not affect survival in patients with endometrial cancer.

CONCLUSION

The risks of endometrial hyperplasia and endometrial cancer were found to be significantly higher in women with than without endometriosis. The presence of endometriosis did not affect overall survival in women with endometrial cancer. Additional long-term prospective studies with adequate control of confounders are needed.

NeiyiKangfu tablets control the progression of endometriosis through inhibiting RAF/MEK/ERK signal pathway by targeting RKIP

BACKGROUND

NeiyiKangfu tablets (NYKF) are widely used clinically for the treatment of endometriosis (EMS), whose mechanism of action has been extensively studied. Researchers have found that NYKF may control the development of ectopic lesions by inhibiting angiogenesis and inflammatory cytokine secretion. Nevertheless, NYKF's mechanism of action remains unclear.

METHODS

In the present study, the function of NYKF in the progression of EMS and the associated underlying mechanism was investigated by in vivo and in vitro experiments. EMS model mice were treated with NYKF and the pro-inflammatory factors and apoptosis of ectopic endometrium as well as RAF/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling activation were assessed. In addition, human endometriosis-derived immortalized entopic stromal (hEM15A) cells transfected with or without RAF kinase inhibitor protein (RKIP)-small-interfering RNA (siRNA) were also treated with NYKF and the proliferation, migration, apoptosis, and RAF/MEK/ERK signaling activation were measured by Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell, and western blot, respectively.

RESULTS

Results showed that NYKF increased the expression of RKIP, inhibited RAF/MEK/ERK signaling activation, and induced apoptosis while inhibiting proliferation and migration both in EMS mice and hEM15A cells. RKIP knockdown could inhibit the effect of NYKF treatment, leading to the activation of RAF/MEK/ERK signaling and the proliferation and migration of hEM15A cells.

CONCLUSIONS

In conclusion, these results suggest that NYKF treatment promotes apoptosis and inhibits proliferation and migration in EMS by inhibiting the RAF/MEK/ERK signaling pathway by targeting RKIP.

Effect of the mode of delivery on the risk of endometriosis recurrence: a retrospective cohort study

OBJECTIVE

To evaluate the risk of endometriosis recurrence according to the mode of delivery (cesarean section vs. vaginal birth) in patients who had become pregnant with a live birth after surgery for endometriosis.

DESIGN

A retrospective cohort study. A Cox proportional-hazards regression was performed to evaluate the risk factors for endometriosis recurrence at 36 months of follow-up after the last pregnancy.

SETTING

Academic hospital.

PATIENT(S)

Patients who have had ≥1 pregnancy with a live birth following conservative surgery for ovarian endometriosis performed from January 2009 to December 2016 at our institution.

INTERVENTION(S)

Patients who underwent ≥1 cesarean section after surgery for endometriosis.

MAIN OUTCOME MEASURES

The recurrence rate of endometriosis after live-birth pregnancies obtained after the first surgery for endometriosis.

RESULTS

Patients with a history of ≥1 cesarean section after surgery for endometriosis have a higher risk of endometriosis recurrence than the patients who have had a vaginal birth, with an adjusted hazard ratio of 2.25 (95% confidence interval, 1.27-3.96).

CONCLUSION

A cesarean section after surgery for endometriosis is associated with a twofold high risk of endometriosis recurrence with respect to vaginal birth. A different follow-up approach may be needed in those patients, and avoiding inappropriate indications for cesarean sections in pregnant patients with a history of surgery for endometriosis is necessary.

Risk factors for coexisting deep endometriosis for patients with recurrent ovarian endometrioma

Aim

The aim of this study was to assess the risk factors for coexisting deep endometriosis (DE) in patients with recurrent ovarian endometrioma (OE).

Methods

We retrospectively reviewed 151 recurrent OE patients who had been diagnosed of OE but not DE at the time of their first surgery and then received a second surgery for recurrent endometriosis with or without DE. Their clinical characteristics at the time of the first and second surgeries were collected. Univariate and multivariate logistic regression analyses were conducted to identify potential risk factors for coexisting DE in patients with recurrent OE.

Results

Among the 151 recurrent OE patients, 46 were diagnosed of DE during the recurrent surgery and included in the DE group, while the remaining 105 patients were included in the non-DE group. In univariate analysis, there were significant differences in terms of uterine retroversion during the primary surgery and the follow-up time after the primary surgery between the DE and non-DE groups. The multivariate analysis also showed that both uterine retroversion and the follow-up time (≥5 years) were associated with the coexistence of DE during the recurrent surgery. The odds ratio (OR) for uterine retroversion was 3.72 [95% confidence interval (CI) 1.62–8.53], and the OR for follow-up time (≥5 years) was 5.03 (95% CI 2.29–11.02).

Conclusions

Our study suggested that for recurrent OE patients, uterine retroversion during the first surgery and a follow-up time of at least 5 years are risk factors for the coexistence of DE in recurrent surgery, early prevention and full preparation before the recurrent surgery should be emphasized in these conditions.

Improvement of Post-Operative Quality of Life in Patients 2 Years after Minimally Invasive Surgery for Pain and Deep Infiltrating Endometriosis

This study addressed the improvement in the quality of life of patients 2 years after minimally invasive surgery for painful deep infiltrating endometriosis (DIE), evaluated with EHP-5 (Endometriosis Health Profile-5) scores and the intensity of dysmenorrhea and dyspareunia. This was a retrospective study, performed in a referral centre for endometriosis, between January 2010 and January 2019. EHP-5 scores were complete for 54 patients, and two subgroups were analysed: classic laparoscopy (CL) vs. robotic laparoscopy (RL), and conservative surgery (ConservS) vs. total surgery (TS). There was an important decrease in 2-year post-operative EHP-5 scores in the global population (pre-op: 61.36 (42.18−68.75) and 2-year post-op: 20.45 (0−38.06); p < 0.001). The Visual Analogic Scale (VAS) was also lower for dysmenorrhea (pre-op: 8 (7−9.75) vs. 2-year post-op: 3 (2−5.25); p < 0.001) and dyspareunia (pre-op: 6 (3.1−8.9) vs. 2-year post-op: 3 (0−6); p < 0.001). In the subgroup analysis, EHP-5 scores were improved in the RL group (pre-op: 65.9 (59.09−71.02) vs. 2-year post-op: 11.4 (0−38.06); p < 0.001) and the CL group (pre-op: 50 (34.65−68.18) vs. 2-year post-op: 27.27 (14.20−40.90); p < 0.001), with a slight advantage for RL (p = 0.04), and the same improvements were found for ConservS (pre-op: 61.4 (38.06−71.59) vs. 2-year post-op: 22.7 (11.93−38.07); p < 0.001) and TS groups (pre-op: 61.59 (51.70−68.75) vs. 2-year post-op: 13.63 (0−44.30); p < 0.001). Minimally invasive surgery improved the quality of life for DIE patients 2 years after surgery, and conservative surgery showed comparable results to total surgery.

[Mystery of endometriosis - catamenial pneumothorax]

The review is devoted to clinical picture, main theories of pathogenesis, traditional and innovative methods of diagnosis and surgical treatment of catamenial pneumothorax. Currently, clinicians prefer magnetic resonance imaging and thoracoscopy for diagnosis of this disease. Various researchers are actively searching for laboratory diagnostic methods that can confirm endometrioid nature of pneumothorax. Treatment and prevention of catamenial pneumothorax are a controversial issue depending both clinical picture and preferences of the attending physician. Currently, the majority of authors believe that hormonal therapy combined with diaphragm resection ensures optimal anti-relapse effect in patients with thoracic endometriosis.

Thai Interest Group for Endometriosis (TIGE) consensus statement on endometriosis-associated pain

This consensus statement has been developed by the Thai Interest Group for Endometriosis (TIGE) for use by Thai clinicians in the diagnosis and management of endometriosis. TIGE is a group of clinical and academic gynaecologists with a particular interest in endometriosis. Endometriosis is an oestrogen-dependent inflammatory disease which causes chronic symptoms such as dysmenorrhoea, chronic pelvic pain, dyspareunia and subfertility, and it is common in reproductive-age women. There is limited overall data on its prevalence in different clinical settings in Thailand, but it is clear that the disease causes significant problems for patients in terms of their working lives, fertility, and quality of life, as well as placing a great burden on national healthcare resources. Decisions about selecting the appropriate treatment for women with endometriosis depend on many factors including the age of the patient, the extent and severity of disease, concomitant conditions, economic status, patient preference, access to medication, and fertility need. Several hormonal treatments are available but no consensus has been reached about the best option for long-term prevention of recurrence. Bearing in mind differences in environment, genetics, and access to the healthcare system, this treatment guideline has been tailored to the particular circumstances of Thai women.

Upregulation of h-TERT and Ki-67 in ectopic endometrium is associated with recurrence of endometriosis

At present, endometriosis remains a worldwide health burden, with the main symptoms of dysmenorrhea, chronic pelvic pain, and infertility, markedly reducing the quality of life (de Ziegler et al., 2010). Although there is no proof that the disease is associated with high mortality, this disorder can significantly contribute to the deterioration of women's general well-being (McPeak et al., 2018). The main current treatment for endometriosis is surgery to remove endometriotic lesions; however, the recurrence rate following surgical treatment is as high as 21.5% at two years and 40.0%‍-‍50.0% at five years post-surgery (Koga et al., 2015). To prevent recurrence, adjuvant treatment with drugs after surgery is recommended to prolong relapse-free intervals. However, it is inconvenient for patients to continuously use such medications in terms of adverse effects and cost (Turk, 2002).

Association of microbial dynamics with urinary estrogens and estrogen metabolites in patients with endometriosis

Endometriosis is an estrogen dependent gynecological disease associated with altered microbial phenotypes. The association among endogenous estrogen, estrogen metabolites, and microbial dynamics on disease pathogenesis has not been fully investigated. Here, we identified estrogen metabolites as well as microbial phenotypes in non-diseased patients (n = 9) and those with pathologically confirmed endometriosis (P-EOSIS, n = 20), on day of surgery (DOS) and ~1–3 weeks post-surgical intervention (PSI). Then, we examined the effects of surgical intervention with or without hormonal therapy (OCPs) on estrogen and microbial profiles of both study groups. For estrogen metabolism analysis, liquid chromatography/tandem mass spectrometry was used to quantify urinary estrogens. The microbiome data assessment was performed with Next generation sequencing to V4 region of 16S rRNA. Surgical intervention and hormonal therapy altered gastrointestinal (GI), urogenital (UG) microbiomes, urinary estrogen and estrogen metabolite levels in P-EOSIS. At DOS, 17β-estradiol was enhanced in P-EOSIS treated with OCPs. At PSI, 16-keto-17β-estradiol was increased in P-EOSIS not receiving OCPs while 2-hydroxyestradiol and 2-hydroxyestrone were decreased in P-EOSIS receiving OCPs. GI bacterial α-diversity was greater for controls and P-EOSIS that did not receive OCPs. P-EOSIS not utilizing OCPs exhibited a decrease in UG bacterial α-diversity and differences in dominant taxa, while P-EOSIS utilizing OCPs had an increase in UG bacterial α-diversity. P-EOSIS had a strong positive correlation between the GI/UG bacteria species and the concentrations of urinary estrogen and its metabolites. These results indicate an association between microbial dysbiosis and altered urinary estrogens in P-EOSIS, which may impact disease progression.

Protein arginine methyltransferase 5 mediates THP-1-derived macrophage activation dependent on NF-κB in endometriosis

Macrophage-induced inflammation is a major factor in the pathogenesis of endometriosis. The underlying mechanisms, however, remain largely unknown. TNF-α, IL-6, IL-10 and C-C motif chemokine 20 (CCL20) levels in endometrial extracts were determined using Luminex cytokine kits. Additionally, protein arginine methyltransferase 5 (PRMT5) levels were measured using reverse transcription-quantitative PCR and western blotting. IL-6 and IP-10 levels in cells were measured using ELISA kits. In the present study, it was revealed that PRMT5 expression at both the mRNA and protein levels in THP-1-derived macrophages was significantly decreased following treatment with serum or extracts of endometrium from patients with endometriosis in the presence of lipopolysaccharide, compared with that in control cells, suggesting a possible role for macrophage-derived PRMT5 in mediating the interaction between macrophages and endometrium in endometriosis. Mechanistically, macrophage PRMT5 expression was regulated in an NF-κB-dependent and Smad2/3-independent manner, indicating that PRMT5 is a downstream target of NF-κB. Importantly, macrophage-derived PRMT5 was required for macrophage activation in endometriosis, as evidenced by the PRMT5-dependent secretion of IL-6 and IFN-γ-induced protein 10 from THP-1-derived macrophages. The present study identified NF-κB-dependent PRMT5 as a novel regulator of macrophage activation in endometriosis. Targeting PRMT5 in macrophages may be a potential therapeutic strategy against endometriosis.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

Risk factors for ovarian endometrioma recurrence following surgical excision: a systematic review and meta‑analysis

PURPOSE

Exploring potential risk factors for OMA recurrence, thereby contributing to the individual management of the disease and improving the patients' prognosis.

METHODS

Data sources PubMed, Embase, the Cochrane Library, CNKI, and Wanfang data were searched systematically before October 2020. We computed the pooled odd ratios or the standard mean difference with their corresponding 95% confidence interval to investigate the impact of involved risk factors on endometrioma recurrence.

RESULTS

The pooled findings of this meta-analysis demonstrated that endometrioma relapse was closely related to age at surgery [SMD (95% CI):  - 0.28 (- - 0.38 to  - 0.17), P < 0.00001], CA125 level [SMD (95% CI): 0.51 (0.14-0.88), P = 0.007], cyst size [SMD (95% CI): 0.35 (0.08-0.62), P = 0.01], dysmenorrhea [OR (95% CI): 1.47 (1.07-2.02), P = 0.02], endometriosis-related surgery history [OR (95% CI): 2.60 (1.84-3.67), P < 0.00001], pre-operative medication [OR (95% CI): 2.13 (1.41-3.22), P = 0.0003], rASRM score [SMD (95% CI): 0.33 (0.20-0.46), P < 0.00001]. Furthermore, post-operative pregnancy was indicated a protective factor for preventing the OMA recurrence after surgery [OR (95% CI): 0.22 (0.09-0.56), P = 0.001] CONCLUSION: Age at surgery, CA125 level, cyst size, dysmenorrhea, endometriosis-related surgery history, pre-operative medication, rASRM score were risk factors for endometrioma relapse. In addition, post-operative pregnancy was a protective factor for preventing recurrence after surgery. However, the effect of bilateral involvement, combination with adenomyosis, or post-operative medication on endometrioma relapse need further investigations.

In the mouse, prostaglandin D2 signalling protects the endometrium against adenomyosis

Adenomyosis is characterised by epithelial gland and mesenchymal stroma invasion of the uterine myometrium. Adenomyosis is an oestrogen-dependent gynaecological disease in which a number of factors, such as inflammatory molecules, prostaglandins (PGs), angiogenic factors, cell proliferation and extracellular matrix remodelling proteins, also play a role as key disease mediators. In this study, we used mice lacking both lipocalin and hematopoietic-PG D synthase (L- and H-Pgds) genes in which PGD2 is not produced to elucidate PGD2 roles in the uterus. Gene expression studied by real-time PCR and hormone dosages performed by ELISA or liquid chromatography tandem mass spectroscopy in mouse uterus samples showed that components of the PGD2 signalling pathway, both PGDS and PGD2-receptors, are expressed in the mouse endometrium throughout the oestrus cycle with some differences among uterine compartments. We showed that PGE2 production and the steroidogenic pathway are dysregulated in the absence of PGD2. Histological analysis of L/H-Pgds-/- uteri, and immunohistochemistry and immunofluorescence analyses of proliferation (Ki67), endothelial cell (CD31), epithelial cell (pan-cytokeratin), myofibroblast (α-SMA) and mesenchymal cell (vimentin) markers, identify that 6-month-old L/H-Pgds-/- animals developed adenomyotic lesions, and that disease severity increased with age. In conclusion, this study suggests that the PGD2 pathway has major roles in the uterus by protecting the endometrium against adenomyosis development. Additional experiments, using for instance transcriptomic approaches, are necessary to fully determine the molecular mechanisms that lead to adenomyosis in L/H-Pgds-/- mice and to confirm whether this strain is an appropriate model for studying the human disease.

Long-Term Medical Therapy after Laparoscopic Excision of Ovarian Endometriomas: Can We Reduce and Predict the Risk of Recurrence?

OBJECTIVES

Up to 32% of women experience anatomic recurrence after conservative surgery for endometriomas, while pain recurs in 10-40% of cases. Long-term postoperative hormonal therapy is recommended to prevent disease recurrence. We evaluated the efficacy of long-term therapy with estroprogestins (EPs) or progestins (Ps) in preventing endometrioma recurrence, as identifiable cysts and subjective symptoms, after laparoscopic excision.

DESIGN

This retrospective cohort study included 375 women submitted to laparoscopic endometrioma excision. Women were followed up at 6 and 12 months and then yearly after surgery. Based on postoperative medical therapy, women were divided into 4 groups: nonusers, cyclic EP users, continuous EP users, and progestogen users. Materials, Setting, Methods: Anamnestic and anthropometric characteristics were collected as well as clinical and surgical data. Gynecological examination, and transvaginal and transabdominal ultrasound scans were performed. Pain (numerical rating score >5) and endometrioma recurrence at ultrasound (ovarian cyst with typical sonographic features ≥10 mm in mean diameter) were recorded at each examination. The reoperation rate in women with recurrence was investigated.

RESULTS

The median follow-up was 3.7 years with a maximum of 16.7 years. Most patients used EPs (119 cyclic and 61 continuous users), 95 used P, and 100 were nonusers. In 135 women (36%), endometriotic cyst recurrence was diagnosed, with a mean diameter of 18.7 ± 10.8 mm (range 10-55 mm). The median recurrent cyst-free time was 7.9 years (95% CI 5.8-10.8). Dysmenorrhea was the first symptom to reappear, affecting 162 patients (43.2%). Upon multivariable regression analysis, continuous users had a lower risk of relapse (OR 0.56, 95% CI 0.32-0.99), in terms of both cysts and symptom recurrence, than patients who received no medications. The reoperation rate was 16.2%.

LIMITATIONS

The main limitation of this study is its retrospective design. Also, women switching therapies throughout the follow-up period were sorted into one of the study groups based on the longest treatment taken, without considering the discontinuation rates.

CONCLUSIONS

Long-term EPs, administered in a continuous regimen and starting immediately after conservative surgery for endometriomas, seem to reduce the disease recurrence risk.

Long-term treatment of endometriosis with dienogest: Real-world results from the VIPOS study

Introduction:

The Visanne Post-approval Observational Study (VIPOS) was designed to assess the safety of dienogest 2 mg (DNG, Visanne) compared to other hormonal endometriosis treatments.

Methods:

Large, prospective, non-interventional, active surveillance study in six European countries (Germany, Poland, Russia, Hungary, Switzerland, and Ukraine). Women with a new hormonal therapy for endometriosis were enrolled by gynecologists and specialized centers between 2010 and 2016 and observed for up to 7 years. Self-administered questionnaires during study entry and follow-up collected information on baseline characteristics, health status and endometriosis treatment. Self-reported clinical outcomes of interest were validated by health care professionals.

Results:

Among the >27,000 enrolled participants, 3262 women started DNG use either at study entry or during follow-up. A total of 798 study participants used DNG during follow-up continuously for 15 months or longer (DNG long-term users). When comparing the occurrence of serious adverse events (SAE) in users treated with DNG, no safety signal emerged for long-term users; the SAE incidence rate per 10,000 women-years was 367.7 (95% CI: 274.1–481.9) in DNG long-term users and 416.4 (349.1–492.5) in short-term users (treated with DNG for less than 15 months).

Conclusions:

Previous data on DNG long-term safety were derived from studies with relatively low numbers of patients and limited follow-up time. VIPOS provided valuable real-world data on the long-term use of DNG 2 mg in around 800 women treated in Europe and observed no safety signal regarding serious adverse events.

When and how should peritoneal endometriosis be operated on in order to improve fertility rates and symptoms? The experience and outcomes of nearly 100 cases

Purpose

To analyze the follow-up results of patients suffering from symptomatic early-stage endometriosis after a consistent laparoscopic peritoneal stripping of the altered peritoneum (peritoneal endometriosis and surrounding inflamed tissue) was performed. This type of endometriosis is resistant to medical therapy and/or impairs fertility.

Methods

Using our prospectively maintained database, we were able to identify all symptomatic women with the suspicion of only peritoneal endometriosis who underwent laparoscopy at our endometriosis center over a period of 5 years. All procedures were carried out in a standardized fashion by one single surgeon, who is highly experienced in minimal invasive surgery, and included a suspended hormonal pretreatment for 2 months. Postoperative outcomes including complications, fertility and recurrence rates were analysed.

Results

Laparoscopic peritonectomy was performed on 94 women. Follow-up data were available in 87% of these cases. At the time of surgery, almost all patients tested showed signs of stage I or II endometriosis (44.7 and 48.9%, respectively). More than three-quarters of the women reported pain relief, inter alia, due to the post-surgical hormonal therapy. About one-third of the patients wanted to have children after the procedure. 62% of them became pregnant and the majority did so without the need for assisted reproductive therapy. In seven women a re-operation was performed.

Conclusion

According to our data, a consistent excision of altered peritoneum followed by adjuvant hormonal therapy and multimodal concepts results in better outcomes for the patient, particularly in regards to pregnancy and recurrence rates.

Recurrence Rate and Risk Factors for the Recurrence of Ovarian Endometriosis after Laparoscopic Ovarian Cystectomy

The aim of this study was to identify the recurrence rate and risk factors for the recurrence of ovarian endometriosis (OE) after laparoscopic cystectomy. This was a retrospective cross-sectional study. Subjects were OE cases who underwent laparoscopic ovarian cystectomy at Bhumibol Adulyadej Hospital (BAH). The period of this study was from January 2008 to December 2017. Ovarian histopathology and at least one-year follow-up after surgery were the prerequisite requirements. A total of 106 OE cases were included in the study. Subjects were classified into recurrence and nonrecurrence groups. It comprised of 24 and 82 cases, respectively. The mean age of the participant was 32.4 years old. The demographic characters of both groups were comparable. The recurrence rate after laparoscopic OE surgery in the present study was 22.6% (24/106). The average largest diameter of OE in the present study was 54.5 mm. Postoperative medical treatment (OR 3.15, 95% CI 1.14-8.74, p = 0.02) and postoperative pregnancy (OR 2.86, 95% CI 1.03-7.93, p = 0.04) were associated factors for recurrence decrement. The recurrence rate of OE after laparoscopic cystectomy was 22.6%. Postoperative medical treatment and postoperative pregnancy were a significant factor that lowered OE recurrence.

OVARIAN ENDOMETRIOSIS: THE MODERN POSSIBILITIES OF RELAPSE PREDICTION

The article summarizes the current understanding of risk factors and mechanisms of ovarian endometriosis relapses, This article summarizes the current understanding of risk factors for relapse, mechanisms of recurrence of endometrioid ovarian cysts, as well as the potential for their prediction using genetic and molecular-biological predictors.

Establishment of an immortalized stromal cell line derived from human Endometriotic lesion

BACKGROUND

Endometriosis is a benign gynecological disease with obviously feature of estrogen-dependence and inflammatory response. The applications of primary endometriotic stromal cells in research of endometriosis are restricted for short life span, dedifferentiation of hormone and cytokine responsiveness. The objective of this study was to establish and characterize immortalized human endometriotic stromal cells (ihESCs).

METHODS

The endometriotic samples were from a patient with ovarian endometriosis and the primary endometriotic stromal cells were isolated from the endometriotic tissues. The primary cells were infected by lentivirus to establish telomerase reverse transcriptase (hTERT)-induced immortalized cells. Quantification of mRNA and proteins was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western Blot. CCK-8 assay and EdU labeling assay were assigned to assess the growth of ihESCs. Karyotype assay was performed to detect the chromosomes of ihESCs. Colony formation assay and nude mouse tumorigenicity assay were used to evaluate colony-formation and tumorigenesis abilities.

RESULTS

ihESCs continuously overexpressed hTERT via infection of lentivirus and significant extended the life span reaching 31 passages. The morphology, proliferation and karyotype of ihESCs remained unchanged. The expression of epithelial-mesenchymal transition (EMT) markers, estrogen-metabolizing proteins and estrogen/progesterone receptors (ERs and PRs) were unaltered. Furthermore, the treatment of estrogen increased the proliferation and EMT of ihESCs. Lipopolysaccharides (LPS) and IL-1β remarkably induced inflammatory response. The clonogenesis ability of ihESCs was consistent with primary cells, which were much lower than Ishikawa cells. In addition, nude mouse tumorigenicity assay demonstrated that ihESCs were unable to trigger tumor formation.

CONCLUSION

This study established and characterized an immortalized endometriotic stromal cell line that exhibited longer life span and kept the cellular morphology and physiological function as the primary cells. The immortalized cells remained normal feedback to estrogen and inflammatory response. Moreover, the immortalized cells were not available with tumorigenic ability. Therefore, ihESCs would be serviceable as in vitro cell tool to investigate the pathogenesis of endometriosis.

The perioperative period: a critical yet neglected time window for reducing the recurrence risk of endometriosis?

While surgery is commonly the management of symptomatic endometriosis when patients do not respond to medical or supportive therapy, recurrence after surgery poses a serious challenge, and repeat surgery increases the risk of premature ovarian failure, adhesion and organ injury. Conceivably, the recurrent endometriotic lesions could arise from minimal residual lesions (MRLs) or from de novo lesions. However, several lines of evidence suggest that the former is more likely. So far, most, if not all, efforts to combat recurrence have been focused on postoperative medication of hormonal drugs to reduce recurrence risk through lesional dormancy and possibly atrophy. However, the perioperative period may exert a disproportionally high impact on the risk of recurrence; it is likely to be amendable for possible intervention but has been generally neglected. Indeed, many perioperative factors are known to or conceivably could facilitate the recurrence of endometriosis through the suppression of cell-mediated immunity due to the activation of adrenergic signaling and the release of prostaglandins. Perioperative use of β-blockers and/or nuclear factor κB/jCycloxygenase 2 (NF-κB/COX-2) inhibitors may boost the cell-mediated immunity suppressed by surgery, resulting in the partial or even complete removal of MRLs and reduced recurrence risk. This is both biologically plausible and supported by a recent experimental study. We call for more research on possible perioperative interventions to reduce the recurrence risk of endometriosis. The potential payoff might be a substantial reduction in the risk of recurrence and cost when compared with the traditional approach of postoperative intervention.

Emodin Reverses the Epithelial-Mesenchymal Transition of Human Endometrial Stromal Cells by Inhibiting ILK/GSK-3β Pathway

Purpose

To explore the exact mechanism through which emodin down-regulates the migration and invasion abilities of endometrial stromal cells. Moreover, to explore the theoretical basis of emodin in the treatment of endometriosis.

Patients and Methods

Endometriosis endometrial stromal cells (EESs) were cultured from 15 women with endometriosis and control endometrial stromal cells (CESs) were cultured from 12 women without endometriosis. The levels of proteins were evaluated by Western blot. The migration and invasion abilities of cells were detected by transwell assays.

Results

The abilities of migration and invasion of EESs were much stronger than those of CESs. After treated with emodin, the migration and invasion abilities of EESs and CESs were significantly down-regulated, and the levels of integrin-linked kinase (ILK) and p-GSK-3β were statistically down-regulated in EESs. Besides that, the expression of keratin was up-regulated while the expression of vimentin, β-catenin and slug were all down-regulated by emodin in a dose- and time-dependent manner. Silencing of ILK gene in EESs also achieved the above effects, which were strengthened by emodin. Conversely, exogenous expression of ILK in CESs increased the expression of p-GSK-3β, which were abrogated by emodin. Furthermore, SB216763 increased migration and invasion abilities of CESs by facilitating the epithelial-mesenchymal transition (EMT) through up-regulating levels of p-GSK-3β, β-catenin and slug, which were also abrogated by emodin.

Conclusion

Emodin inhibits the migration and invasion abilities of human endometrial stromal cells by reversing the EMT via ILK/GSK-3β pathway. So, emodin may be considered as a promising targeted therapy for endometriosis.

Atypical endometriosis is related to a higher recurrence rate

OBJECTIVES

The aims of this study were to evaluate the clinical characteristics and recurrence rate of atypical endometriosis (AE)¹ compared to typical endometriosis (TE) in addition to the malignant transformation rate among a large cohort.

STUDY DESIGN

The medical records of 2681 patients who had undergone surgical treatment of ovarian endometrioma between January 2008 and September 2019 were retrospectively reviewed. The patients were divided into AE (n = 86) and TE (n = 2595) groups. Patients' characteristics and recurrence rates were evaluated and compared between the two groups.

RESULTS

The mean size of ovarian cysts was significantly larger in the AE group (7.6 ± 3.5 cm vs 6.7 ± 3.3 cm, p = 0.01) and the proportion of nulliparous women was significantly lower in AE group (65.1 % vs 77.8 %, p = 0.008). Otherwise, there were no statistically significant differences in patient characteristics between the two groups. After Cox regression analyses with IPTW was adjusted, the risk factors for recurrent endometrioma were higher preoperative CA125 level >48 U/mL (hazard ratio [HR] = 2.741; 95 % confidence interval [CI] = 1.517-4.952; p < 0.001), multilocular cyst (HR = 1.909; 95 % CI = 1.128-3.230; p = 0.016), and atypical endometriosis (HR = 2.666; 95 % CI = 1.659-4.284; p < 0.001). The AE group displayed a significantly higher cumulative recurrence rate than the TE group (p = 0.0057, log-rank test). No patients were diagnosed with atypical endometriosis to malignant transformation during the follow-up periods. However, two typical endometriosis patients experienced borderline malignancy and serous carcinoma, respectively.

CONCLUSION

Recurrence rates for AE were higher than for TE. Although the AE group included no patient with malignant transformation in this study, considering the higher recurrence as well as the possibility of malignant transformation, long-term close surveillance is warranted.

RhoA/ROCK pathway mediates the effect of oestrogen on regulating epithelial-mesenchymal transition and proliferation in endometriosis

Endometriosis is a benign gynaecological disease appearing with pelvic pain, rising dysmenorrhoea and infertility seriously impacting on 10% of reproductive‐age females. This research attempts to demonstrate the function and molecular mechanism of RhoA/ROCK pathway on epithelial‐mesenchymal transition (EMT) and proliferation in endometriosis. The expression of Rho family was abnormally changed in endometriotic lesions; in particular, RhoA and ROCK1/2 were significantly elevated. Overexpression of RhoA in human eutopic endometrial epithelial cells (eutopic EECs) enhanced the cell mobility, epithelial‐mesenchymal transition (EMT) and proliferation, and RhoA knockdown exhibited the opposite function. Oestrogen up‐regulated the RhoA activity and expression of RhoA and ROCK1/2. RhoA overexpression reinforced the effect of oestrogen on promoting EMT and proliferation, and RhoA knockdown impaired the effect of oestrogen. oestrogen receptor α (ERα) was involved with the regulation of oestrogen on EMT and proliferation and up‐regulated RhoA activity and expression of RhoA and ROCK1/2. The function of ERα was modulated by the change in RhoA expression. Furthermore, phosphorylated ERK that was enhanced by oestrogen and ERα promoted the protein expression of RhoA/ROCK pathway. Endometriosis mouse model revealed that oestrogen enhanced the size and weight of endometriotic lesions. The expression of RhoA and phosphorylated ERK in mouse endometriotic lesions was significantly elevated by oestrogen. We conclude that abnormal activated RhoA/ROCK pathway in endometriosis is responsible for the function of oestrogen/ERα/ERK signalling, which promoted EMT and proliferation and resulted in the development of endometriosis.

Comparison of effect of preoperative dienogest and gonadotropin-releasing hormone agonist administration on laparoscopic cystectomy for ovarian endometriomas

PURPOSE

To compare the effects of preoperative dienogest (DNG) and gonadotropin-releasing hormone (GnRH) agonist administration on the improvement of preoperative symptoms and surgical outcomes in patients who underwent laparoscopic cystectomy for ovarian endometriomas.

METHODS

Seventy patients who were scheduled for laparoscopic surgery were enrolled in the study. They were divided into two groups: 35 patients who received DNG for 4 months preoperatively (group D) and 35 patients who received low-dose sustained-release goserelin acetate for 4 months preoperatively (group G). Preoperative outcomes, including pain score associated with endometriosis, using the numerical rating scale (NRS), adverse events of hormonal therapy and Kupperman index (KI) before and after treatment, surgical outcomes including total surgical duration and blood loss, and postoperative recurrence of endometrioma were compared between the two groups.

RESULTS

Regarding preoperative symptoms, NRS and KI at 4 months after preoperative hormonal therapy were significantly lower in group D than in group G (NRS, 5.3 ± 5.5 vs. 2.7 ± 3.9; P = 0.01; KI, 16.0 ± 11.0 vs. 9.2 ± 7.6; P = 0.006). Regarding adverse events, the incidence of hot flashes was significantly lower in group D than in group G (P < 0.001). Meanwhile, the incidence of breast pain and metrorrhagia was significantly higher in group D than in group G (P = 0.04 and P < 0.001, respectively). The total surgical duration and blood loss were not significantly different between the groups. At 12 months after surgery, ovarian endometrioma did not recur in either group.

CONCLUSION

Preoperative administration of DNG is more valuable for patients with endometriosis and scheduled for laparoscopic surgery to improve symptoms with good efficacy and tolerability than the administration of GnRH agonist.

Reproductive capacity and recurrence of disease after surgery for moderate and severe endometriosis - a retrospective single center analysis

BACKGROUND

Endometriosis can be associated with considerable pain and sterility. After surgical excision of moderate or severe endometriosis lesions, the rate of recurrence reaches up to 67%. The objective of this retrospective study was to establish the recurrence and pregnancy rates following surgical resection of stage III/IV endometriosis lesions. Indications for operation were endometriosis symptoms, sonographic findings and/or infertility.

METHODS

A total of 456 patients who underwent stage III/IV endometriosis surgery between 2004 and 2014 were sent a questionnaire relating to their postoperative medical treatment, pregnancies, relief of symptoms and recurrence. Responses of 206 patients (45.2%) and their clinical data were analysed for this study.

RESULTS

A total of 66.5% (N = 137) of patients had stage III disease, and 33.5% (N = 69) had stage IV disease. The average age was 37 years (17-59). A total of 63.1% (N = 130) of surgeries were performed by laparoscopy, 21.8% (N = 45) were performed by laparotomy and 15% (N = 31) were performed by conversion. Complete resection of endometriosis lesions was achieved in 90.8% of patients (N = 187). After surgery, 48.5% (N = 100) of the women did not receive hormonal treatment; the main reason was the desire for children in 53%. Complete or partial relief in complaints was achieved in 93.2% (N = 192). The rate of recurrence was 21.8% (N = 45). The statistically significant factors that was associated with a higher risk to develop recurrence was an age < 35 (p < 0.005). After surgery, 65.8% (79/120) of patients who wished to have children became pregnant. There was a statistically significant association among a higher postoperative pregnancy rate and age < 35 (p < 0.003) in multivariate logistic regression analysis and laparoscopic surgical access in univariate logistic regression analysis (p < 0.01).

CONCLUSION

We assessed the high percentage of complete or partial relief of symptoms of 93.2%, the high postoperative pregnancy rate of 65.8% and the low rate of recurrence of 21.8% compared to international literature to be very encouraging for women suffering from moderate and severe endometriosis. Though laparoscopy is considered the 'gold standard'of endometriosis surgery, laparotomy still may be indicated in patients with extensive endometriosis especially to preserve reproductive function.

Treatment of endometriosis-associated pain with linzagolix, an oral gonadotropin-releasing hormone-antagonist: a randomized clinical trial

OBJECTIVE

To study the effect of a new investigational oral gonadotropin-releasing hormone antagonist, linzagolix, on endometriosis-associated pain (EAP).

DESIGN

A multinational, parallel group, randomized, placebo-controlled, double-blind, dose-ranging trial.

SETTING

Clinical centers.

PATIENT(S)

Women aged 18-45 years with surgically confirmed endometriosis and moderate-to-severe EAP.

INTERVENTION(S)

The interventions were 50, 75, 100, or 200 mg linzagolix (or matching placebo) administered once daily for 24 weeks.

MAIN OUTCOME MEASURE(S)

The primary endpoint was the number of responders (≥30% reduction in overall pelvic pain) after 12 weeks. Other endpoints included dysmenorrhea, non-menstrual pelvic pain, serum estradiol, amenorrhea, quality of life (QoL) measures, and bone mineral density (BMD).

RESULT(S)

Compared with placebo, doses ≥ 75 mg resulted in a significantly greater proportion of responders for overall pelvic pain at 12 weeks (34.5%, 61.5%, 56.4%, and 56.3% for placebo, 75, 100, and 200 mg, respectively). A similar pattern was seen for dysmenorrhea and non-menstrual pelvic pain. The effects were maintained or increased at 24 weeks. Serum estradiol was suppressed, QoL improved, and the rate of amenorrhea increased in a dose-dependent fashion. Mean BMD loss (spine) at 24 weeks was <1% at doses of 50 and 75 mg and increased in a dose-dependent fashion up to 2.6% for 200 mg. BMD of femoral neck and total hip showed a similar pattern.

CONCLUSION(S)

Linzagolix significantly reduced EAP and improved QoL at doses of 75-200 mg and decreased BMD dose-dependently.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02778399.

Age at surgery and recurrence of ovarian endometrioma after conservative surgery: a meta-analysis including 3125 patients

PURPOSE

To evaluate the association between age at surgery and recurrence rate of endometrioma. Data sources PubMed, Embase, and the Cochrane Library were searched up to October 2019.

METHODS

We determined the pooled relative risk (RR) and 95% confidence intervals (CIs) to assess the relationship between age at surgery and the recurrence rate of endometrioma after surgery. Begg's funnel plot and Egger's linear regression was used to assess any publication bias.

RESULTS

A total of 3125 patients from 10 studies were finally enrolled in this meta-analysis. The recurrence rate decreased with increasing age (RR = 0.93, 95% CI = 0.91-0.95, P = 0.451). Subgroup analysis demonstrated that the pooled RR was 0.926 (95% CI 0.906-0.947, P < 0.001) for a cut-off < 35, and 0.886 (95% CI 0.775-1.040, P = 0.14) for a cut-off ≥ 35. Begg's funnel plot and Egger's linear regression test showed no evidence of publication bias.

CONCLUSION

This meta-analysis suggested that younger age might be a high-risk factor for the recurrence of ovarian endometrioma after conservative surgery.

Ion Channels in The Pathogenesis of Endometriosis: A Cutting-Edge Point of View

BACKGROUND

Ion channels play a crucial role in many physiological processes. Several subtypes are expressed in the endometrium. Endometriosis is strictly correlated to estrogens and it is evident that expression and functionality of different ion channels are estrogen-dependent, fluctuating between the menstrual phases. However, their relationship with endometriosis is still unclear.

OBJECTIVE

To summarize the available literature data about the role of ion channels in the etiopathogenesis of endometriosis.

METHODS

A search on PubMed and Medline databases was performed from inception to November 2019.

RESULTS

Cystic fibrosis transmembrane conductance regulator (CFTR), transient receptor potentials (TRPs), aquaporins (AQPs), and chloride channel (ClC)-3 expression and activity were analyzed. CFTR expression changed during the menstrual phases and was enhanced in endometriosis samples; its overexpression promoted endometrial cell proliferation, migration, and invasion throughout nuclear factor kappa-light-chain-enhancer of activated B cells-urokinase plasminogen activator receptor (NFκB-uPAR) signaling pathway. No connection between TRPs and the pathogenesis of endometriosis was found. AQP5 activity was estrogen-increased and, through phosphatidylinositol-3-kinase and protein kinase B (PI3K/AKT), helped in vivo implantation of ectopic endometrium. In vitro, AQP9 participated in extracellular signal-regulated kinases/p38 mitogen-activated protein kinase (ERK/p38 MAPK) pathway and helped migration and invasion stimulating matrix metalloproteinase (MMP)2 and MMP9. ClC-3 was also overexpressed in ectopic endometrium and upregulated MMP9.

CONCLUSION

Available evidence suggests a pivotal role of CFTR, AQPs, and ClC-3 in endometriosis etiopathogenesis. However, data obtained are not sufficient to establish a direct role of ion channels in the etiology of the disease. Further studies are needed to clarify this relationship.

Potential use of ellagic acid for endometriosis treatment: its effect on a human endometrial cell cycle, adhesion and migration

EA treatment decreases cell adhesion and migration of endometrial cells and alters the progression of an endometrial stromal cell line cycle.

Establishment and characterization of immortalized human eutopic endometrial stromal cells

PROBLEM

The application of primary eutopic endometrial cells from endometriosis patients in research is restricted for short life span, dedifferentiation of hormone responsiveness.

METHOD OF STUDY

Human telomerase reverse transcriptase (hTERT)-induced immortalized cells (iheESCs) were infected by lentivirus. mRNA level was examined by qRT-PCR, and protein expression was quantified by Western blot. CCK-8 and EdU assay were assigned to assess the proliferation. The migration and invasion of cells were assessed by transwell assay. Clone formation assay and nude mouse tumorigenicity assay were used to evaluate colony-formation and tumorigenesis abilities.

RESULTS

hTERT mRNA and protein were significantly expressed higher in iheESCs compared to primary cells. iheESCs grew without morphological change for 42 passages which is much longer than 18 passages of primary cells. There was no obvious difference between primary cells and iheESCs in growth, mobility, and chromosome karyotype. Furthermore, the expression of epithelial-mesenchymal transition (EMT) markers and estrogen/progesterone receptors remained unchanged. The decidualization of iheESCs could be induced by progesterone and cAMP. Estrogen increased the proliferation and mobility of iheESCs, and lipopolysaccharides (LPS) induced the IL-1β and IL-6 promoting inflammatory response. The colony-forming ability of iheESCs, like primary cells, was lower than Ishikawa cells. In addition, tumorigenicity assay indicated that iheESCs were unable to trigger tumor formation in BALB/c nude mouse.

CONCLUSIONS

This study established and characterized iheESCs that kept the cellular physiology of primary cells and were not available with tumorigenic ability. Thus, iheESCs would be useful as in vitro cell model to investigate pathogenesis of endometriosis.

Surgical treatment of endometriosis: prognostic factors for better quality of life

The present study investigated the effect of surgical treatment of endometriosis on physical and mental health. We undertook a prospective survey including 153 premenopausal women with histological diagnosis of endometriosis. The Short Form 12 (SF-12) questionnaire comprising physical and mental component scales was used. Two groups of patients were distinguished: Group A (n = 42) with SF-12 scores above the median in both physical and mental scales; Group B (n = 111) with SF-12 scores below the median in either physical or mental scale. Group A was diagnosed and operated for endometriosis for the first time at an older age (30 vs. 26 years), had undergone more frequently a single surgical intervention (64% vs. 46%), was less affected by symptom or lesion recurrence and had reported less intense current pain symptoms than Group B. Having the first endometriosis surgery at a later age was an independent predictor of better health status (adjusted odds ratio 1.146 per year, 95% confidence interval 1.058-1.242) after accounting for the potential confounding effects of reoperation, pelvic pain and time elapsed since the first surgery. In conclusion, patients with endometriosis who had a single surgery at an older age have good symptom control and better quality of life (QoL).

Recurrent endometriosis: a battle against an unknown enemy

Recurrence of endometriosis after conservative surgery is not an uncommon finding. There is no uniformity, however, on what the term 'recurrence' means. Recurrence is variously defined in the literature as the relapse of pain, clinical or instrumental detection of an endometriotic lesion, repeat rise in CA 125 levels, or evidence of recurrence found during repeat surgery. Consequently, the reported recurrence rate varies widely (0-89%) in the different series, depending on its definition and the type of study performed. As endometriosis recurrence seems to be an indeterminate enemy, we set out to examine exactly what we were fighting in our everyday battle. In this narrative review, we aimed to seek an answer to questions related to endometriosis recurrence, some of which are often asked by our patients.

Add-on effect of Guizhi Fuling formula to mifepristone for endometriosis: A meta-analysis of randomized controlled trials

BACKGROUND

Guizhi Fuling pill, a famous traditional Chinese herbal formula, has been widely used for treatment of gynecological diseases. This meta-analysis sought to evaluate the add-on effect of Guizhi Fuling capsule (GZFL) to mifepristone in women with endometriosis.

METHODS

A comprehensively literature search was conducted using Pubed, Embase, Cochrane Library, Wanfang, CNKI, VIP databases from their inceptions to January 25, 2019. Randomized controlled trials that compared GZFL plus mifepristone to mifepristone alone for treatment of endometriosis were eligible. Main outcomes were pregnancy, reduction of the recurrence, and serum level of follicle-stimulating hormone, luteinizing hormone, estradiol or progesterone.

RESULTS

A total of 1052 women with endometriosis from 10 trials were identified and analyzed. Meta-analyses showed that GZFL plus mifepristone was superior to mifepristone in reducing the recurrence of endometriosis (RR 0.40; 95% CI 0.27-0.59) and improving the pregnancy (risk ratio [RR] 1.74; 95% confidence intervals [CI] 1.40-2.17). Moreover, adjuvant treatment with GZFL also significantly reduced serum level of estradiol (mean difference [MD] -20.83 pmol/L; 95% CI -34.01 to -7.65) and progesterone (MD -0.18 mmol/L; 95% CI -0.23 to -0.12). However, there were no significant differences in serum level of follicle-stimulating hormone (MD -0.42 U/L; 95% CI -1.16 to 0.31) and luteinizing hormone (MD -0.04 U/L; 95% CI -0.43 to 0.34).

CONCLUSION

GZFL as adjuvant therapy to mifepristone appears to have additional benefits in preventing recurrence of endometriosis and improving pregnancy among women with endometriosis. However, these conclusions should be interpreted with caution due to the methodological flaws of the included trials.

Endometriosis Knowledgebase: a gene-based resource on endometriosis

Endometriosis is a complex, benign, estrogen-dependent gynecological disorder with an incidence of ~10% women in reproductive age. The implantation and growth of endometrial cells outside the uterus leads to the development of endometriosis. Endometriosis is also associated with comorbid conditions like cardiovascular and autoimmune diseases. The absence of non-invasive diagnostic markers, delayed diagnosis, high risk of recurrence of the disease on surgical removal of the tissue and absence of a definitive cure for endometriosis makes it imperative to gain insights into the complex etiology of endometriosis. A plethora of genes identified from blood and endometrial biopsies, involved in different pathways like steroid metabolism, angiogenesis, inflammation, etc. have been associated with endometriosis. However, the exact mechanism and genetic etiology of endometriosis still remain unclear. The polygenic nature of the disease, incongruent phenotypic manifestations in different ethnic populations and information scattered in literature makes it difficult to delineate the sub-network of genes that will aid in disease diagnosis and effective treatment. Endometriosis Knowledgebase is a manually curated database with information on genes associated with endometriosis. It holds information on 831 genes, their associated polymorphisms, gene ontologys, pathways and diseases. Genes in the database are enriched in pathways important for cell signaling, immune regulation and reproduction. A genetic overlap is seen between endometriosis and cancers, endocrine/reproductive, nervous system, immune and metabolic diseases. Network analysis of genes in the Endometriosis Knowledgebase helped predict 13 new candidate genes for endometriosis. These genes were found to be enriched in biological processes associated with endometriosis. The Endometriosis Knowledgebase and incorporated tools for gene and sequence-based analysis will benefit both researchers and clinicians working in the realm of reproductive biology.

Factors associated with deep infiltrating endometriosis versus ovarian endometrioma in China: a subgroup analysis from the FEELING study

BACKGROUND

To compare potential factors associated with deep infiltrating endometriosis (DIE) versus ovarian endometrioma (OMA) among endometriosis patients in China.

METHODS

A subgroup analysis of factors associated with DIE versus OMA was performed in Chinese women from the FEELING study. This study included 156 OMA patients and 78 DIE patients. Retrospective information on symptoms and previous medical history was collected via face-to-face interviews; patients also completed a questionnaire to provide information on current habits. Univariate and multivariate logistic regression analyses were conducted to identify potential factors that are associated with DIE versus OMA.

RESULTS

From univariate analysis, women who were married, at older age, had any siblings, prior pregnancy, or longer time since age at menarche on the day of visit were more likely to be diagnosed with DIE (P < 0.05). Also, the incidence of previous uterine surgery, menstrual and ovulatory disorders, deep dyspareunia, and gastrointestinal symptoms during menstruation were major factors that were significantly associated with the diagnosis of DIE (P < 0.05). Multivariate analysis showed that women with any siblings, gastrointestinal symptoms during menstruation, or eating a greater number of fruit/vegetables per day were more likely to be diagnosed with DIE. Meanwhile, eating organic food and experiencing stress were major factors that are associated with the diagnosis of OMA.

CONCLUSIONS

The findings provide additional information on the potential risk factors that are associated with DIE, compared with OMA among Chinese endometriosis patients. The results may help to better understand DIE versus OMA, and aid in earlier risk stratification and diagnosis of the patients.

TRIAL REGISTRATION

NCT01351051 . Registered 10 May 2011.

Efficacy of levonorgestrel releasing intrauterine system as a postoperative maintenance therapy of endometriosis: A meta-analysis

OBJECTIVE

To compare the efficacy of levonorgestrel releasing intrauterine system (LNG-IUS) with other treatments as a postoperative maintenance therapy for endometriosis in terms of pain reduction, recurrence prevention, side effects and patients' satisfaction.

STUDY DESIGN

We searched MEDLINE, EMBASE, and the Cochrane Library from January 1986 until February 2018. Two evaluators independently extracted and reviewed prospective and retrospective articles based on pre-determined selection criteria. Outcomes were expressed as mean difference (MD), risk ratios (RR) or odds ratios (OR) in a meta-analysis model, using Revman software.

RESULTS

Among the 962 studies, 7 studies were selected: 7 studies included 4 randomized controlled trials with 212 patients, 1 prospective cohort study with 88 patients, and 2 retrospective studies with 191 patients. A meta-analysis showed that LNG-IUS was significantly effective in reducing pain after surgery (MD = 12.97, 95% confidence interval (CI): 5.55-20.39), with a comparable effect to gonadotropin-releasing hormone analogues (MD = -0.16, 95% CI: -2.02 to 1.70). LNG-IUS was also effective in decreasing the recurrence rate (RR = 0.40, 95% CI: 0.26-0.64), with an effect comparable to OC (OR = 1.00, 95% CI: 0.25-4.02) and danazol (RR = 0.30, 95% CI: 0.03-2.81). Furthermore, patients' satisfaction with LNG-IUS was significantly higher than that with OC (OR = 8.60, 95% CI: 1.03-71.86). However, vaginal bleeding was significantly higher in the LNG-IUS group than in the gonadotropin-releasing hormone analogue group (RR = 27.0, 95% CI: 1.71-425.36).

CONCLUSION

Our meta-analysis found a positive effect of LNG-IUS as a postoperative maintenance therapy for endometriosis on pain relief, prevention of dysmenorrhea recurrence, and patients' satisfaction.

[Immunohistochemical predictors of recurrent ovarian endometriomas after laparoscopic surgery]

OBJECTIVE

To investigate the expression of proliferation and apoptotic factors (Ki-67, Bcl-2), inflammatory factors (NF-kβ p65, COX-2), adhesion factors (β-catenin), estrogen (ER-α) and progesterone receptors (PR-α) in ovarian endometrioma (OE) in patients with recurrent OE by an immunohistochemical assay.

SUBJECT AND METHODS

This investigation enrolled 48 reproductive-aged patients with OE. According to the course of the disease during a follow-up period of 1.5 years after surgical treatment, the biomaterial obtained from the examined patients was divided into two groups: 1) an OE capsule from 19 patients with recurrent OE (a study group); 2) an OE capsule from 28 patients without recurrent OE (a comparison group). This investigation used histological and immunohistochemical examinations. The histological analysis of the OE capsule was performed following a standard procedure. Their immunohistochemical analysis was carried out using the Tissue-Tek Quick-Ray kit that allows the preparation of paraffin blocks with a large number of tissue samples (tissue microarrays). Antibodies to Ki-67 (clone 30-9, VENTANA), Bcl-2 (clone 124, VENTANA), NF-kβ p65 (clone p65, 'Spring Bioscience Corp.'), COX-2 (clone CX-294, Agilent), β-catenin (clone 14, VENTANA), ER-α (clone SP1, VENTANA), and PR-α (clone 1E2, VENTANA) were also employed in the investigation. The specimens were prepared according to a standard protocol using a Ventana Ultra immunohistostainer. Positive and negative controls were used to correctly carry out immunohistochemical tests. Statistical analysis was performed using the applied statistical analysis programs Statistica 10.0 and Microsoft Excel.

RESULTS

The patients with recurrent OE had a significantly decreased expression of Ki-67 (2.86% vs. 9.69%; р=0.044) in the epithelial component of the OE capsule; a significantly lower expression of NF-kβ p65 (2.54 vs. 3.5; р=0.0082) and СОХ-2 (0.231 vs. 1.381; р=0.0025) in the stromal component of the OE capsule, a significantly increased expression of β-catenin (2.5 vs. 1.59; р=0.017) in the stromal component of the OE capsule; a significantly increased expression of PR-α (188.46 vs. 71.15; р=0.028) in the epithelial component of an OE capsule. The expression of ER-α (stromal component, 266 vs. 256.84; p=0.48; epithelial component, 251.54 vs. 233.85, p=0.82) and Bcl-2 (stromal component, 0.33 vs. 0.25; p=0.85; epithelial component, 0.944 vs. 0.625; p=0.31) in the OE capsule is not statistically significantly different between the study patient groups.

CONCLUSION

The immunohistochemical difference in the expression of a number of the markers under study can serve as the basis for a further investigation of these markers as predictors of recurrent OE after surgical treatment. Further investigations of these factors will also be able to examine the molecular mechanisms underlying the pathogenesis of recurrent OE, which will make it possible to affect these mechanisms in order to eliminate the fundamental causes of a recurrence of this disease.

Basic mechanisms of vascularization in endometriosis and their clinical implications

BACKGROUND

Vascularization is a major hallmark in the pathogenesis of endometriosis. An increasing number of studies suggests that multiple mechanisms contribute to the vascularization of endometriotic lesions, including angiogenesis, vasculogenesis and inosculation.

OBJECTIVE AND RATIONALE

In this review, we provide an overview of the basic mechanisms of vascularization in endometriosis and give special emphasis on their future clinical implications in the diagnosis and therapy of the disease.

SEARCH METHODS

Literature searches were performed in PubMed for English articles with the key words 'endometriosis', 'endometriotic lesions', 'angiogenesis', 'vascularization', 'vasculogenesis', 'endothelial progenitor cells' and 'inosculation'. The searches included both animal and human studies. No restriction was set for the publication date.

OUTCOMES

The engraftment of endometriotic lesions is typically associated with angiogenesis, i.e. the formation of new blood vessels from pre-existing ones. This angiogenic process underlies the complex regulation by angiogenic growth factors and hormones, which activate intracellular pathways and associated signaling molecules. In addition, circulating endothelial progenitor cells (EPCs) are mobilized from the bone marrow and recruited into endometriotic lesions, where they are incorporated into the endothelium of newly developing microvessels, referred to as vasculogenesis. Finally, preformed microvessels in shed endometrial fragments inosculate with the surrounding host microvasculature, resulting in a rapid blood supply to the ectopic tissue. These vascularization modes offer different possibilities for the establishment of novel diagnostic and therapeutic approaches. Angiogenic growth factors and EPCs may serve as biomarkers for the diagnosis and classification of endometriosis. Blood vessel formation and mature microvessels in endometriotic lesions may be targeted by means of anti-angiogenic compounds and vascular-disrupting agents.

WIDER IMPLICATIONS

The establishment of vascularization-based approaches in the management of endometriosis still represents a major challenge. For diagnostic purposes, reliable angiogenic and vasculogenic biomarker panels exhibiting a high sensitivity and specificity must be identified. For therapeutic purposes, novel compounds selectively targeting the vascularization of endometriotic lesions without inducing severe side effects are required. Recent progress in the field of endometriosis research indicates that these goals may be achieved in the near future.