Management of Uterine Fibroids and Sarcomas: The Palermo Position Paper.

BACKGROUND: Uterine fibroids are benign monoclonal tumors originating from the smooth muscle cells of the myometrium, constituting the most prevalent pathology within the female genital tract. Uterine sarcomas, although rare, still represent a diagnostic challenge and should be managed in centers with adequate expertise in gynecological oncology. OBJECTIVES: This article is aimed to summarize and discuss cutting-edge elements about the diagnosis and management of uterine fibroids and sarcomas. METHODS: This paper is a report of the lectures presented in an expert meeting about uterine fibroids and sarcomas held in Palermo in February 2023. OUTCOME: Overall, the combination of novel molecular pathways may help combine biomarkers and expert ultrasound for the differential diagnosis of uterine fibroids and sarcomas. On the one hand, molecular and cellular maps of uterine fibroids and matched myometrium may enhance our understanding of tumor development compared to histologic analysis and whole tissue transcriptomics, and support the development of minimally invasive treatment strategies; on the other hand, ultrasound imaging allows in most of the cases a proper mapping the fibroids and to differentiate between benign and malignant lesions, which need appropriate management. CONCLUSIONS AND OUTLOOK: The choice of uterine fibroid management, including pharmacological approaches, surgical treatment, or other strategies, such as high-intensity focused ultrasound (HIFU), should be carefully considered, taking into account the characteristics of the patient and reproductive prognosis.

Impact of Indication for Oocyte and Embryo Reception on Reproductive and Obstetric Outcomes.

OBJECTIVES: This study aimed to assess if the indication for oocyte reception (OR) or embryo reception (ER) impacts the reproductive and obstetric outcomes by evaluating our experience at a tertiary fertility centre and by performing a literature review on this subject. Several previous studies have reported that, in contrast to other types of fertility treatment, the indication for OR/ER seems to have little impact on the outcomes. However, the compared indication groups vary considerably between these studies, and some data indicates worse outcomes in patients who developed premature ovarian insufficiency (POI) due to Turner syndrome or treatment with chemotherapy/radiotherapy. DESIGN: A retrospective analysis of all cases of OR/ER at a tertiary fertility centre from 2001 until 2020 was conducted. We analysed 584 cycles from 194 individual patients. A literature review on the impact of indication on reproductive or obstetric outcomes of OR/ER was performed using the following databases: PubMed/MEDLINE, Embase, and the Cochrane Library. A total of 27 studies were included and analysed. PARTICIPANTS, SETTING, METHODS: For the retrospective analysis, patients were divided into three major indication groups: failure of autologous assisted reproductive technology, POI, and genetic disease carrier. To assess reproductive outcomes, we determined pregnancy rate, implantation rate, miscarriage rate, and live birth rate. For comparing obstetric outcomes, we reviewed the term of birth, mode of delivery, and birthweight. Outcomes were compared using Fisher's exact test, χ2 test, and one-way ANOVA utilizing the GraphPad tool. RESULTS: There were no significant differences in reproductive and obstetric outcomes between the three major indication groups in our population, in line with the findings reported by existing literature. Data on impaired reproductive outcomes in patients with POI after chemotherapy/radiotherapy are conflicting. Obstetrically, these patients are at higher risk of preterm birth and possibly also low birthweight, especially after abdomino-pelvic or total body irradiation. For patients with POI due to Turner syndrome, most data suggest similar pregnancy rates but a higher rate of pregnancy loss, and obstetrically an increased risk of hypertensive disorders and caesarean section. LIMITATIONS: The small number of patients in the retrospective analysis resulted in low statistical power when evaluating differences between smaller subgroups. There were some missing data on the occurrence of complications during pregnancy. Our analysis covers a period of 20 years, during which several technological innovations have also been made. CONCLUSIONS: Our study shows that the important heterogeneity in couples treated with OR/ER does not significantly impact their reproductive or obstetric outcomes, except for POI due to Turner syndrome or treatment with chemotherapy/radiotherapy, where there seems to be an important uterine/endometrial component that cannot be entirely overcome by providing a healthy oocyte.

An irreversible inhibitor of 17ß-hydroxysteroid dehydrogenase type 1 inhibits estradiol synthesis in human endometriosis lesions and induces regression of the non-human primate endometriosis.

Endometriosis is a gynecological disorder affecting about 10% of women and can lead to invalidating painful symptoms and infertility. Since there is no current definitive cure for this disease, new therapeutic options are necessary. 17ß-Hydroxysteroid dehydrogenase type 1 (17ß-HSD1) is involved in the production of estradiol (E2), the most potent estrogen in women, and of 5-androstene-3ß,17ß-diol (5-diol), a weaker estrogen than E2, but whose importance increases after menopause. 17ß-HSD1 is therefore a pharmacological target of choice for the treatment of estrogen-dependent diseases such as endometriosis. We developed a targeted-covalent (irreversible) and non-estrogenic inhibitor of 17ß-HSD1, a molecule named PBRM, and herein evaluated its efficiency for the treatment of endometriosis. In a cell-free assay containing estrone (E1), the natural substrate of 17ß-HSD1, PBRM was able to block the formation of E2 in a collection of 50 human endometriosis lesions from a different clinical feature type, location, and phase. When given orally by gavage at 15 mg/kg to baboons, the resulting plasmatic concentration of PBRM was found to be sufficiently high (up to 125 ng/mL) for an efficacy study in a non-human primate (baboon) endometriosis model. After 2 months of treatment, the number of lesions/adhesions decreased in 60% of animals (3/5) in the PBRM-treated group, compared to the placebo group which showed an increase in the number of lesion/adhesions in 60% (3/5) of animals. Indeed, the total number of lesions/adhesions decreased in treated group (-6.5 or -19% when excluding one animal) while it increased in the control group receiving a placebo (+11%). Analysis of specific endometriotic lesions revealed that PBRM decreased the number of red lesions (-67%; 8/12) and white lesions (-35%; 11/31), but not of blue-black lesions. Similarly, PBRM decreased the surface area of dense adhesions and filmy adhesions, as compared to placebo. Also, PBRM treatment did not significantly affect the number of menstrual days. Finally, this targeted covalent inhibitor showed no adverse effects and no apparent toxicity for the duration of the treatment. These data indicate that 17ß-HSD1 inhibitor PBRM is a promising candidate for therapy targeting endometriosis and supports the need of additional efforts toward clinical trials.

Patient-derived organoids from endometrial disease capture clinical heterogeneity and are amenable to drug screening.

Endometrial disorders represent a major gynaecological burden. Current research models fail to recapitulate the nature and heterogeneity of these diseases, thereby hampering scientific and clinical progress. Here we developed long-term expandable organoids from a broad spectrum of endometrial pathologies. Organoids from endometriosis show disease-associated traits and cancer-linked mutations. Endometrial cancer-derived organoids accurately capture cancer subtypes, replicate the mutational landscape of the tumours and display patient-specific drug responses. Organoids were also established from precancerous pathologies encompassing endometrial hyperplasia and Lynch syndrome, and inherited gene mutations were maintained. Endometrial disease organoids reproduced the original lesion when transplanted in vivo. In summary, we developed multiple organoid models that capture endometrial disease diversity and will provide powerful research models and drug screening and discovery tools.

Endometriosis biomarkers: Will codevelopment in academia-industry partnerships result in new and robust noninvasive diagnostic tests?

Endometriosis is an important gynecological disease, affecting 10% of reproductive age women, and associated with pain, infertility, reduced quality of life, and high health economic cost. Except for ultrasound detection of ovarian endometriotic cysts, the gold standard for diagnosis is laparoscopy, leading to diagnostic delays of 5-10 years. Accurate noninvasive biomarkers are needed, especially for symptomatic women with a normal gynecological ultrasound, to triage them towards medical or surgical treatment and to monitor their treatment outcome. Such biomarkers are not available today, largely because the research focus has been on discovery, not on reproducibility and validation. Academia/industry partnerships can move this field forward by validation of promising markers, consensus on endometriosis phenotypes/controls and desirable accuracy (sensitivity/specificity). Such partnerships should increase the quality and reproducibility of target discovery work and foster global consensus on the use of relevant preclinical/animal models, if they are managed with complete (financial) transparency and with the aim to translate innovation into products benefiting patients. It is essential that mutual objectives are clarified between industry and academia partners including intellectual property policy, critical decision points, funding agreements, milestones and timelines, with a clear strategy for project termination/change of strategy, a restriction on publications till new discoveries have been patented, considering that a minority of novel findings can be translated into new therapeutic targets, diagnostics, or marketed products.

Functional expression of the mechanosensitive PIEZO1 channel in primary endometrial epithelial cells and endometrial organoids.

Successful pregnancy requires the establishment of a complex dialogue between the implanting embryo and the endometrium. Knowledge regarding molecular candidates involved in this early communication process is inadequate due to limited access to primary human endometrial epithelial cells (EEC). Since pseudo-pregnancy in rodents can be induced by mechanical scratching of an appropriately primed uterus, this study aimed to investigate the expression of mechanosensitive ion channels in EEC. Poking of EEC provoked a robust calcium influx and induced an increase in current densities, which could be blocked by an inhibitor of mechanosensitive ion channels. Interestingly, RNA expression studies showed high expression of PIEZO1 in EEC of mouse and human. Additional analysis provided further evidence for the functional expression of PIEZO1 since stimulation with Yoda1, a chemical agonist of PIEZO1, induced increases in intracellular calcium concentrations and current densities in EEC. Moreover, the ion channel profile of human endometrial organoids (EMO) was validated as a representative model for endometrial epithelial cells. Mechanical and chemical stimulation of EMO induced strong calcium responses supporting the hypothesis of mechanosensitive ion channel expression in endometrial epithelial cells. In conclusion, EEC and EMO functionally express the mechanosensitive PIEZO1 channel that could act as a potential target for the development of novel treatments to further improve successful implantation processes.

Progesterone Receptor Status Predicts Response to Progestin Therapy in Endometriosis.

Context: Progestin-based therapy is the first-line treatment for managing endometriosis-associated pain. However, response to progestins is currently variable and unpredictable. Predictive markers for response to progestin-based therapy would allow for a personalized approach to endometriosis treatment. Objective: We hypothesize that progesterone receptor (PR) levels in endometriotic lesions determine response to progestin-based therapy. Design: Retrospective cohort study. Setting: Academic center. Patients: Fifty-two subjects with histologically confirmed endometriosis and a previous documented response to hormonal therapy were included. Interventions: Immunohistochemistry was performed on sections of endometriotic lesions using a rabbit polyclonal IgG for detection of PR-A/B. Main Outcome Measures: The Histo (H)-score was used for quantifying PR status. Response to progestin-based therapies was determined from review of the electronic medical record. Results: H-score was higher in responders compared with nonresponders. Subjects were categorized into three groups: high (H-score > 80, n = 7), medium (H-score 6 to 80, n = 28), and low (H-score ≤ 5, n = 17) PR status. The threshold of PR > 80 was associated with a 100% positive predictive value. The threshold of PR < 5 was associated with a 94% negative predictive value. Conclusion: PR status is strongly associated with response to progestin-based therapy. Receptor status in endometriosis could be used to tailor hormonal-based regimens after surgery, and negate trialing progestin-based therapy to determine resistance. Ascertainment of PR status may allow for a novel, targeted, precision-based approach to treating endometriosis.

Functional Expression of TRP Ion Channels in Endometrial Stromal Cells of Endometriosis Patients.

Endometriosis is a common gynecological disease that is characterized by the presence of functional endometrial-like lesions in the abdominal cavity. Aside from epithelial cells, these lesions consist of stromal cells that have the capacity to migrate, adhere, proliferate, and induce neuro- and lymphangiogenesis, which allows them to survive at ectopic locations. However, the exact underlying mechanisms that regulate these changes are yet to be elucidated. The common ground of these processes, however, is the second messenger, calcium. In this regard, members of the superfamily of transient receptor potential (TRP) ion channels, which are known to be calcium-permeable and expressed in the endometrium, have emerged as key regulators. Here, we assessed the molecular and functional expression of TRP channels in stromal cells isolated from the eutopic endometrium of endometriosis patients and controls. Using RT-qPCR, high mRNA levels of TRPV2, TRPV4, TRPM4, TRPM7, TRPC1, TRPC3, TRPC4, and TRPC6 were observed in the whole endometrium throughout the menstrual cycle. Additionally, and in line with previous reports of control patients, TRPV2, TRPV4, TRPC1/4, and TRPC6 were present in human endometrial stromal cells (hESC) from endometriosis patients both at the molecular and functional level. Moreover, proliferation and migration assays illustrated that these parameters were not affected in stromal cells from endometriosis patients. Furthermore, comparison between eutopic and ectopic endometrial samples revealed that the RNA expression pattern of TRP channels did not differ significantly. Collectively, although a functional expression of specific ion channels in hESCs was found, their expression did not correlate with endometriosis.

Of Mice and Women: A Laparoscopic Mouse Model for Endometriosis.

STUDY OBJECTIVE: To demonstrate how a novel laparoscopic approach allows the development of a mouse model for endometriosis after seeding menstrual endometrium from donor mice into the abdominal cavity of syngeneic recipient mice. DESIGN: A step-by-step video description of the techniques used to adapt the estrous cycle of mice towards a menstrual cycle and to subsequently induce endometriosis via laparoscopic seeding of menstrual endometrium. SETTING: University research institute. ETHICS: All animal experiments were ethically approved by KU Leuven, Belgium (ethical approval number: P031/2013). INTERVENTIONS, MEASUREMENTS, AND MAIN RESULTS: Oophorectomized female C57BL/6JRj mice received a series of estrogen injections. Next, a progesterone pellet was administered, together with a second series of estrogen injections. In addition, decidualization of the endometrium was induced with an intrauterine sesame oil stimulus. Four days later the progesterone pellet was removed and menstruation started [1]. Five hours after the progesterone pellet was removal the uterus was harvested, and the menstrual endometrium was dissected and seeded into the abdominal cavity of syngeneic recipient mice to induce endometriosis [2] using a laparoscopic approach [3]. Uterus and lesions were removed from the recipient mice 1 week after induction, and tissues were immunohistochemically stained for H&E, vimentin, and cytokeratin. CONCLUSION: In this video we show a novel methodology to induce endometriosis in mice using laparoscopic inoculation of syngeneic menstrual endometrium, mimicking Sampson's theory of retrograde menstruation [4]. Compared with currently available rodent models, our model offers a less invasive and more physiologic way for fundamental and preclinical endometriosis research, with a high endometriosis incidence and lesion take rate.

Development of organoids from mouse and human endometrium showing endometrial epithelium physiology and long-term expandability.

The endometrium, which is of crucial importance for reproduction, undergoes dynamic cyclic tissue remodeling. Knowledge of its molecular and cellular regulation is poor, primarily owing to a lack of study models. Here, we have established a novel and promising organoid model from both mouse and human endometrium. Dissociated endometrial tissue, embedded in Matrigel under WNT-activating conditions, swiftly formed organoid structures that showed long-term expansion capacity, and reproduced the molecular and histological phenotype of the tissue's epithelium. The supplemented WNT level determined the type of mouse endometrial organoids obtained: high WNT yielded cystic organoids displaying a more differentiated phenotype than the dense organoids obtained in low WNT. The organoids phenocopied physiological responses of endometrial epithelium to hormones, including increased cell proliferation under estrogen and maturation upon progesterone. Moreover, the human endometrial organoids replicated the menstrual cycle under hormonal treatment at both the morpho-histological and molecular levels. Together, we established an organoid culture system for endometrium, reproducing tissue epithelium physiology and allowing long-term expansion. This novel model provides a powerful tool for studying mechanisms underlying the biology as well as the pathology of this key reproductive organ.

Endometriosis is associated with aberrant metabolite profiles in plasma.

OBJECTIVE: To identify metabolites that are associated with and predict the presence of endometriosis. DESIGN: Metabolomics study using state-of-the-art mass spectrometry approaches. SETTING: University hospital and universities. PATIENT(S): Twenty-five women with laparoscopically confirmed endometriosis (cases) and 19 women with laparoscopically documented absence of endometriosis (controls). None of the women included in this study had received oral contraception or GnRH agonists for a minimum of 1 month before blood collection. INTERVENTION(S): Plasma collection. MAIN OUTCOME MEASURE(S): Metabolite profiles were generated and interrogated using multiple mass spectrometry methods, that is, high performance liquid chromatography coupled with negative mode electrospray ionization tandem mass spectrometry, UPLC-MS/MS, and ultra performance liquid chromatography-electroSpray ionization-quadrupole time-of-flight (UPLC-ESI-Q-TOF). Metabolite groups investigated included phospholipids, glycerophospholipids, ether-phospholipids, cholesterol-esters, triacylglycerol, sphingolipids, free fatty acids, steroids, eicosanoids, and acylcarnitines. RESULT(S): A panel of acylcarnitines predicted the presence of endometriosis with 88.9% specificity and 81.5% sensitivity in human plasma, with a positive predictive value of 75%. However, due to data limitations the outcome of the receiver operating characteristic curve analysis was not significant. CONCLUSION(S): A diagnostic model based on acylcarnitines has the potential to predict the presence and stage of endometriosis.

The Presence of Endometrial Cells in Peritoneal Fluid of Women With and Without Endometriosis.

To reinforce Sampson's theory of retrograde menstruation in the pathogenesis of endometriosis, proof should be provided that during menstruation endometrial cells are present in peritoneal fluid (PF). We hypothesize that the prevalence of PF samples containing endometrial cells is higher in patients with endometriosis than in controls without endometriosis during menstruation. We selected from our biobank PF samples of 17 reproductive-age women with (n = 9) or without (n = 8) endometriosis who had received a diagnostic laparoscopy for investigation of pain/infertility. Peritoneal fluid had been collected during laparoscopy in the menstrual phase of the cycle, centrifuged, and the resulting pellet was stored at -80°C. About 5-µm sections of frozen PF pellets were stained using the Dako Envision Flex system with primary antibodies against epithelial cell adhesion molecule (Ep-CAM; endometrial epithelial cells), CD10 (endometrial stromal cells), prekeratin (epithelial/mesothelial cells), vimentin (endometrial/mesothelial/immune cells), calretinin (mesothelial cells), and CD68 (macrophages). The PF cells positive for Ep-CAM were detected in 5 of 9 patients with endometriosis and 6 of 8 controls ( P = .62). CD10 stained positively in 6 of the 9 patients with endometriosis and 3 of the 8 controls ( P = .35). Calretinin and prekeratin staining showed the presence of mesothelial cells in all pellets. Vimentin stained approximately 100% of the PF cells. CD68+ macrophages represented >50% of cells in all pellets. The prevalence of PF samples containing endometrial epithelial and stromal cells was not higher in patients with endometriosis than in controls without endometriosis during menstruation. Our findings question the relevance of endometrial cells in PF for the pathogenesis of endometriosis and support the importance of other mechanisms such as immune dysfunction and/or endometrial stem cells.

Laparoscopic Surgery: A New Technique to Induce Endometriosis in a Mouse Model.

BACKGROUND: This prospective pilot study was designed to induce endometriosis in a mouse model using laparoscopy, a less invasive and more precise approach than laparotomy. We aimed to achieve a peritoneal implant rate of at least 50% by varying both duration of anesthesia and intra-abdominal insufflation pressure. METHODS: Female BALB/cANnCrl mice in metestrus or diestrus were used as donors (n = 5) or recipients (n = 20) of uterine transplant tissue. Each recipient mouse was laparoscopically inoculated with 10 uterine pieces (range: 10-12) from donor mice into the abdominal cavity. Before starting the study, recipient mice were randomly assigned to 4 groups with variable duration of anesthesia (ketamine/xylazine or pentobarbital) and variable intra-abdominal pressure (5 or 15 mm Hg). One week after laparoscopy, endometriosis incidence and peritoneal implant take rate were documented visually during laparotomy. The retrieved lesions were histologically analyzed. RESULTS: Laparoscopic inoculation of uterine pieces in recipient mice resulted in an endometriosis incidence of 100% (20/20 animals) and an individual peritoneal implant take rate of 60% (121/206), ranging from 17% (2/12) till 83% (10/12), without differences between the 4 subgroups, and with a histological confirmation rate of 92% (58/63). CONCLUSIONS: To the best our knowledge, this is the first report showing that endometriosis can be induced by laparoscopic surgery in rodents, with a 100% incidence and a median peritoneal implant take rate of 60%. This laparoscopic model offers important advantages over traditional laparotomy models that are limited by surgery-associated trauma and/or adhesion formation.

Challenges in the development of novel therapeutic strategies for treatment of endometriosis.

INTRODUCTION: Endometriosis is an estrogen-dependent disease that results in pelvic pain and infertility. Its treatment is often frustrating due to limited medical treatment options, complex surgical treatment and high recurrence rates. Despite the advances in our understanding of the pathogenesis over the last decades and the consequent novel therapeutic strategies, no new drugs have been introduced in daily clinical practice. AREAS COVERED: In the first part we present an overview of the pathogenesis of endometriosis. In the second part we discuss how new insights have led to the development of novel nonhormonal strategies for the treatment of endometriosis, focusing on anti-inflammatory and anti-angiogenic agents. In the third part we describe the problems encountered in the translation from experimental drugs to routine medicine for the treatment of endometriosis. EXPERT OPINION: Despite the multitude of agents that have been tested in preclinical trials, only few drugs have passed to the stage of clinical testing and none have been introduced into clinical practice. It is our opinion that the major challenges in the translation from novel agents for endometriosis is due to the use of inadequate rodent models and a lack of standardization in the design and reporting of preclinical endometriosis models.