Endometriosis-associated cancer

Metabolic profile of follicular fluid in patients with ovarian endometriosis undergoing IVF: a pilot study

RESEARCH QUESTION

What are the metabolic characteristics of follicular fluid in patients with ovarian endometriosis undergoing IVF?

DESIGN

This was an exploratory cohort study on endometriosis. In total, 19 infertile patients with ovarian endometriosis diagnosed by laparoscopy, and 23 controls matched in terms of age and body mass index (women with infertility due to male or tubal factors) were enrolled in this study. All patients underwent IVF treatment with a gonadotrophin-releasing hormone antagonist protocol, and follicular fluid was collected at oocyte retrieval. The metabolomics of follicular fluid samples was analysed using an ultra-high-performance liquid chromatography Orbitrap Exploris mass spectrometer (UHPLC-OE-MS). The best combination of biomarkers was selected by performing stepwise logistic regression analysis with backward elimination.

RESULTS

Fifteen metabolites were identified as biomarkers associated with endometriosis. A final model containing 8-hydroxy-2-deoxyguanosine, biotin, n-acetyl-L-methionine and n-methylnicotinamide was constructed. Receiver operating characteristic analysis confirmed the value of these parameters in diagnosing endometriosis, with sensitivity of 94.7% and specificity of 95.7%. Enrichment analysis via the Kyoto Encyclopedia of Genes and Genome showed that 15 metabolites were enriched in eight metabolic pathways.

CONCLUSION

Metabolomics based on UHPLC-OE-MS effectively characterized the metabolomics analysis of follicular fluid in patients with ovarian endometriosis. These findings may provide a new basis for better understanding of how diseases progress, and for the discovery of new biomarkers.

Molecular Regulator Driving Endometriosis Towards Endometrial Cancer: A Multi-Scale Computational Investigation to Repurpose Anti-Cancer drugs

Endometriosis is a gynecological disorder among reproductive-aged women. Recent epidemiological investigations suggest endometriosis increases the risk of endometrial cancer. However, the molecular entity leading to endometriosis-to-endometrial cancer is largely unknown. This study aimed to combine a variety of computational approaches to identify the key therapeutic target promoting endometriosis-to-endometrial cancer and screen potential inhibitors against target to prevent cancer development. Our systematic investigations, includes transcriptomic profiling, protein network, pharmacophore modeling, docking, binding free energy calculation, dynamics simulation, and quantum mechanics. The gene expression analysis on endometriosis and endometrial cancer was performed and showed 108 shared upregulated genes in both conditions. Further construction of interaction network with 108 genes showed intercellular adhesion molecule 1 (ICAM1) to be a crucial molecule with a high degree of connectivity that influences vital mechanisms related to cancer pathways. We then generated ligand-based pharmacophore models using established ICAM1 inhibitors. Among the models, the ADRRR_8 pharmacophore exhibited a robust area under curve (AUC = 0.83), was employed to screen 1739 anti-cancer drugs. On screening, 421 anti-cancer drugs displayed ICAM1-inhibiting pharmacophore features. Further, the docking of 421 drugs with ICAM1 showed lanreotide (-7.80 kcal/mol) with better affinity than the reference ICAM1 inhibitor (-3.59 kcal/mol). Further validation though binding free energy and dynamics simulation of the lanreotide-ICAM1 complex showed a high binding affinity of -55.90 kcal/mol and contributed stable confirmation. According to quantum chemical calculations, lanreotide's electronic properties favour ICAM1 binding with highest occupied molecular orbital was -6.91 eV and lowest unoccupied molecular orbital was -3.93 eV. Our study supports using lanreotide to treat endometriosis, which could delay or prevent endometrial cancer. These predictions need to be confirmed and examined to determine the use of lanreotide in endometriosis treatment.

Diaphragmatic clear cell carcinoma with Lynch syndrome after surgery for atypical endometrial hyperplasia and ovarian endometriosis: A case report

Clear cell carcinoma (CCC) of the diaphragm is rare, with an origin that is reported to be associated with malignant transformation of extraperitoneal endometriosis. Lynch syndrome (LS) is an autosomal dominant hereditary cancer syndrome caused by germline pathogenic variants in one of the DNA mismatch repair (MMR) genes, MLH1, MSH2, MSH6 and PMS2. Women with LS have a significantly increased lifetime risk of endometrial and ovarian cancer. CCC is a common histology of endometriosis- and LS-associated malignancy. The present study describes the case of a 51-year-old woman with an intra-abdominal mass found during a routine physical examination. The patient had undergone total hysterectomy and bilateral adnexectomy for atypical endometrial hyperplasia (AEH) and ovarian endometriosis, respectively, 3 years previously. Enhanced computed tomography showed a mass on the surface of the liver. Laparoscopic examination of the abdominal cavity revealed a tumor on the underside of the right diaphragm, which was then surgically excised. Pathological examination of the excised tumor, along with immunohistochemistry, led to a diagnosis of CCC. Since LS was suspected due to the genetic family history of the patient, microsatellite instability analysis was performed on the diaphragmatic tumor, and the results were positive. Immunohistochemistry was performed for MMR proteins in AEH and CCC cells, both of which revealed loss of MSH2 and MSH6 expression. Following detailed genetic counseling, genetic testing of MMR genes was performed, revealing a germline pathogenic variant in MSH2 (c.1000C>T, p.Gln344*), thus confirming the diagnosis of LS. To the best of our knowledge, this is the first case report of concurrent diaphragmatic CCC and LS. Patients with LS and endometriosis are at risk of developing ovarian cancer or intra-abdominal malignant tumors. In addition, immunohistochemistry screening for MMR proteins should be considered in patients with AEH and a family history of LS-related cancer, to enable early clinical intervention in cases of endometrial cancer.

Research Progress of Caspase in Endometriosis

Endometriosis, a common chronic gynecological disease, refers to the presence and proliferation of endometrial tissue in locations other than the uterine cavity. Approximately 6 to 10% of the population of women of childbearing age are known to have endometriosis; the most common clinical signs are pelvic pain and infertility. Although endometriosis is a benign disease, it exhibits some typical features of malignant tumors, such as proliferation, invasion, metastasis, and recurrence. Endometriosis is considered a chronic, inflammatory, and estrogen-dependent disease, and multiple factors contribute to its occurrence and development. In recent years, increasing attention has been given to the role of apoptosis in the pathogenesis of this disease. Some researchers believe that spontaneous apoptosis of the endometrium is critical in maintaining its normal structure and function, and abnormal apoptosis can promote the occurrence and development of endometriosis. Inflammation is another likely process in the pathogenesis of endometriosis. Inflammation mediates the adhesion, proliferation, differentiation, and invasion of ectopic lesions of endometriosis, primarily by regulating the function of immune cells and increasing the level of proinflammatory cytokines in body fluids. The ultimate initiators of apoptosis and inflammatory cell death (pyroptosis) are the caspase family proteases. In this article, we review the progress in recent years in caspase function as well as the possible role of these enzymes in the pathogenesis of endometriosis, indicating potential treatment strategies.

Endometriosis MRI: Atypical cases, pitfalls and mimics

Endometriosis is a common but often underdiagnosed chronic gynaecological disease. Endometriosis mimics other diagnoses both clinically and radiographically, presenting a diagnostic challenge. Endometriosis can be categorised as superficial pelvic endometriosis, deep invasive endometriosis (DIE) or endometrioma. Endometrioma and DIE, including polypoid endometriosis, can masquerade as invasive neoplasms. Endometriosis can be misdiagnosed in less common locations or during pregnancy. Ultrasound is the initial investigation for endometriosis; however, MRI is advantageous in providing a larger field of view for increased detection of nodules as well as distinguishing malignancy with greater certainty. This review highlights endometriosis mimics, pitfalls and atypical cases on MRI.

Expression of HIF-1α, Ki67, SMA and E-cadherin in endometriosis, endometrial and ovarian carcinoma

INTRODUCTION

Endometriosis is a benign gynecological condition that shares many characteristics with cancer cells, including immune evasion, survival, adhesion, invasion, and angiogenesis. The simultaneous investigation of tissue hypoxia, EMT, and proliferative index in endometriosis, endometrial, and ovarian carcinomas may provide new insight into the evolution and progression of gynecological neoplasms.

Case report: Malignant transformation of ovarian endometrioma during long term use of dienogest in a young lady

Endometriosis is a benign disease, which is also regarded as a precursor to ovarian malignancy. Dienogest is a progestin treatment for endometriosis with efficacy and tolerability. A 35-year-old Taiwanese lady with ovarian endometrioma had taken dienogest for the last 5 years. During sonographic follow-up, surgery was suggested owing to suspicious of malignant transformation of ovarian endometrioma. While she hesitated and turned to receive two cycles of oocyte retrieval because of nulliparity. Meanwhile, more papillary growth in the ovarian endometrioma with intratumor flow was found during follow-up. Laparoscopic enucleation was performed later, and pathology revealed clear cell carcinoma with peritoneal involvement, at least FIGO stage IIB. She then underwent debulking surgery to grossly no residual tumor and received adjuvant chemotherapy with no tumor recurrence in post-operative 17-months follow-up. Considering fertility preservation, conservative treatment of ovarian endometrioma is typically indicated for those women who have not yet completed childbearing. However, malignant transformation may still occur despite long-term progestin treatment. Therefore, careful image follow-up is still indispensable.

Primary vaginal cancer after hysterectomy for benign conditions: a systematic review of the literature

Background

Primary vaginal cancer is a rare condition. Some studies have revealed an increased risk of vaginal cancer among patients who have undergone hysterectomy for premalignant and malignant cervical disease. However, there is limited literature available on primary vaginal cancer following hysterectomy for benign conditions.

Objectives

This review aimed to investigate available evidence on clinical characteristics, treatments, and outcomes of primary vaginal cancer following hysterectomy for benign diseases. Additionally, we provide a case of a patient who developed primary vaginal cancer 10 years after undergoing hysterectomy for abnormal uterine bleeding.

Search strategy

We conducted a comprehensive literature search on PubMed, Scopus, Web of Science using a combination of title and abstract represented by "hysterectomy", and "vaginal cancer"; "vaginal neoplasm"; and "cancer of vagina". No article type restrictions were applied.

Main results

Eight studies with a total of 56 cases were included in this review. The main symptom observed was vaginal bleeding. Squamous cancer was found to be the most common type, followed by adenocarcinoma. The majority of vaginal cancer cases occurred approximately 10 years after undergoing hysterectomy. The most common location of the tumor was in the vaginal apex. The management approaches varied and details were available in 25 cases. Among these, 7 cases were treated with radiotherapy alone, 1 case received concurrent chemoradiation therapy, and the of rest of the cases underwent surgery as the primary treatment, with or without additional adjuvant therapy. Data of follow-up was available for 15 cases, with 2 cases resulting in death and 2 cases experiencing recurrence. The other cases were alive and well at the time of considered follow up.

Conclusion

Primary vaginal cancer after hysterectomy for benign conditions is an extremely rare condition. It is essential to have high-level evidence to guide the screening and treatment strategy for this rare condition. A part of women who have undergone hysterectomy for benign disorders can benefit from vaginal cytology evaluation. It is reasonable to postpone the initial screening after surgery and to extend the interval between subsequent screenings. Further retrospective case-control trials are expected to determine which specific subgroups of patients mentioned above might most potentially benefit from screening. The treatment decision for vaginal cancer after hysterectomy is more favorable to radiotherapy-based management rather than surgery. Vaginal endometrioid adenocarcinoma may arise from the malignant transformation of endometriosis. More studies are expected to investigate the correlation between these two diseases.

Endometriosis and epithelial ovarian cancer: a two-sample Mendelian randomization analysis

Endometriosis, a prevalent condition, has long been recognized as a chronic and debilitating ailment affecting an estimated 1790 million women worldwide. Observational studies have established a correlation between endometriosis and ovarian cancer. Thus, we endeavored to employ Two-Sample Mendelian Randomization, utilizing summary statistics from a Genome-Wide Association Study of endometriosis and epithelial ovarian cancer, with genetic markers serving as proxies for epithelial ovarian cancer. The analysis revealed a significant correlation between these entities, with an odds ratio (OR) of 1.23 (95% CI 1.11-1.36). Upon histotype-specific examination, robust evidence emerged for an association of endometriosis with the risk of endometrioid carcinoma (OR 1.49, 95% CI 1.24-1.81), clear cell carcinoma (OR 2.56, 95% CI 1.75-3.73), and low malignant potential tumors (OR 1.28, 95% CI 1.08-1.53). These findings provide a theoretical framework for prospective investigations aimed at enhancing the potential therapeutic efficacy of managing endometriosis in averting the onset and progression of ovarian cancer.

Squamous cell carcinoma associated with endometriosis in the uterus and ovaries: A case report

BACKGROUND

Endometriosis is a common benign gynecological disease that causes dysmenorrhea in women of childbearing age. Malignant tumors derived from endometriosis are rarely reported and are found in only 1% of all patients with endometriosis. Here, we report a well-differentiated squamous cell carcinoma (SCC) caused by squamous metaplasia of endometriosis that co-occurred in the uterus and ovaries.

CASE SUMMARY

A 57-year-old postmenopausal woman had a 6-month history of irregular uterine bleeding. The uterus and adnexa were examined by computed tomography, and there were two solid cystic masses in the pelvis and right adnexa. Histological findings of surgical specimens showed well-differentiated SCC arising from squamous metaplasia of ectopic endometrial glands in the uterus and ovaries. The patient received chemotherapy after surgery and was followed up for 3 mo without metastasis.

CONCLUSION

The continuity between ectopic endometrial glands and SCC supports that SCC originates from ectopic endometrial glands with metaplasia towards squamous epithelium.

Spatiotemporal Trends and Age-Period-Cohort Analysis for the Burden of Endometriosis-Related Infertility: An Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Endometriosis is a common nonfatal gynecological disease, and infertility is one of its main dangers. Endometriosis-related infertility causes serious damage to women's health and places a burden on women of reproductive age. The aim of this study was to describe the current burden of endometriosis-associated infertility and to analyze its spatiotemporal trends.

METHODS

Age-standardized prevalence rate (ASPR) data from 1990 to 2019 for Endometriosis-related primary infertility (ERPI) and secondary infertility (ERSI) were obtained from the Global Burden of Disease Study (GBD) 2019. These data spanning three decades cover the global, sociodemographic index (SDI) regions, GBD regions, and 204 countries and territories. Spatiotemporal trends were analyzed by calculating the estimated annual percentage change (EAPC) and using a time-period-cohort model.

RESULTS

Globally, the ASPR of ERPI and ERSI showed a weak downward trend from 1990 to 2019, with EAPCs of -1.25 (95% CI: -1.39 to -1.11) and -0.6 (95% CI: -0.67 to -0.53), respectively. The spatiotemporal trends in ERPI and ERSI varied substantially between regions and age groups. When endometriosis-related infertility burden was linked to SDI values, a strong negative correlation was observed between the ASPR of ERSI and its EAPC and SDI values. When modeling with age-period-cohort, ERPI burden was found to be highest at ages 20-25 years, while ERSI burden was persistently higher at ages 20-45 years. Using 2000-2004 as the reference period, both ERPI and ERSI burden decreased with each year among women. Significant variability in burden between regions was found for the birth cohort factor.

CONCLUSIONS

The global burden of endometriosis-related infertility declined minimally from 1990 to 2019. However, this burden varied considerably across regions, age groups, periods, and birth cohorts. The results of this study reflect spatiotemporal trends in the burden of endometriosis-related infertility over the study period and may be used to help improve health management, develop timely and effective prevention and control strategies, and provide epidemiologic theoretical evidence for reducing the burden for endometriosis-related infertility.

Identification of iron metabolism-related predictive markers of endometriosis and endometriosis-relevant ovarian cancer

Endometriosis is associated with ovarian cancers, mainly endometrioid and clear-cell carcinomas. Iron metabolism has been shown to play a role in endometriosis. Therefore, it is vital to explore the relationship between iron metabolism and ovarian cancer and to identify novel markers for diagnostics and therapeutics. The endometriosis dataset GSE51981 and the ovarian cancer dataset GSE26712 were obtained from the gene expression omnibus database, and differentially expressed genes were identified. Iron metabolism genes were obtained from molecular signatures database, and hub genes from the 3 datasets were obtained. Seven hub genes were identified by bioinformatic analysis, and 3 hub genes (NCOA4, ETFDH, and TYW1) were further selected by logistic regression, which were verified in an independent endometriosis dataset (GSE25628) and ovarian cancer dataset (GSE14407), showing good predictive diagnostic value (area under the receiver operating characteristic curve of 0.88 and 0.9, respectively). Gene Ontology, gene set enrichment analysis, and immune infiltration analysis further confirmed the related functions, pathways, and immune relationship between iron metabolism and ovarian cancer. This study highlights the potential of targeting iron metabolism in the prevention of potential ovarian cancer and in the further exploration of endometriosis and endometriosis-relevant ovarian cancer therapeutics.

Identification of key modules and candidate genes associated with endometriosis based on transcriptome data via bioinformatics analysis

BACKGROUNDS

Endometriosis is a common disease in women, but the signaling pathways and genes involved remain unclear. This study screened genes that were differentially expressed in ectopic endometrium (EC) and eutopic endometrium (EU) in endometriosis and provided clues for subsequent experimental verification.

METHODS

Endometriosis samples were harvested from inpatients that underwent surgery from 2017 to 2019 with pathological evidence of endometriosis. We assessed the mRNA expression profiles in endometriosis and further conducted gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, Gene Set Enrichment Analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) to identify potential biomarkers in endometriosis. Finally, we further validated hub genes using public databases and immunohistochemistry assays.

RESULTS

The upregulated DEGs of ectopic endometrium from endometriosis patients were mainly involved in cell adhesion, MAPK signaling, PI3K-Akt signaling pathways, cytokine receptor interactions, and epithelial-mesenchymal transformation (EMT)-associated signaling pathways. The downregulated DEGs between ectopic endometrium and eutopic endometrium were related to decidualization-associated genes in endometriosis. The correlated gene modules in eutopic endometrial cells were mainly enriched in cell adhesion, embryo implantation and inflammation. The eutopic and ectopic endometrial lesions in endometriosis were involved in the EMT process. Furthermore, we identified 18 co-expression modules during WGCNA analysis. Hub genes in the pale turquoise module were FOSB, JUNB, ATF3, CXCL2, FOS, etc. Significantly enriched KEGG pathways included the TNF, MAPK, foxO, oxytocin, and p53 signaling pathways. Enrichment pathways were directly related to immune surveillance, stem cell self-renewal, and epithelial-mesenchymal transformation. Several pathways and modules of endometriosis are related to cancer-associated pathways, which substantiates the correlation between endometriosis and various gynecological tumors.

CONCLUSIONS

Endometriosis was tightly correlated with EMT and fibrosis mediated by inflammatory immunity, cytokines, estrogen, kinases and protooncogene through transcriptomics. Overall, our findings lay the groundwork for understanding the pathogenesis of endometriosis and its relationship with malignant transformation.

Artificial Intelligence Based Study Association between p53 Gene Polymorphism and Endometriosis: A Systematic Review and Meta-analysis

BACKGROUND

The P53 gene is critical to the onset and progression of cancers. Currently, relevant study findings indicate that the p53 gene may have a strong association with the risk of endometriosis, but these findings have not been united. To gather more statistically meaningful clinical data, we used meta-analysis to examine the relationship between the rs1042522 single nucleotide polymorphism of the tumor suppressor gene p53 and the incidence of endometriosis.

METHODS

Through a comprehensive literature survey of PubMed, MEDLINE, EMBASE, Springer, and Web of Science literature databases, we obtained a clinical control case study on the relationship between p53 gene polymorphism and the prevalence of female endometriosis and finally traced the relevant references included. The quality of the literature included in this study was evaluated, and Revman5.3 was used to complete the meta-analysis.

RESULTS

This research includes eight publications. The total number of cases in the study group was 1551, whereas the total number of cases in the control group was 1440. The findings of the sensitivity analyses of each omitted piece of the literature revealed no significant difference. The results of the meta-analysis showed that there were significant differences in the GG gene frequency (OR = 0.56, 95%CI (0.38, 0.92), P = 0.003), allele G (OR = 2.46, 95%CI (1.41,4.29), P = 0.002), and allele C (OR = 0.62, 95%CI (0.46, 0.84), P = 0.002) between the study group and the control group (P < 0.01), but there was no significant difference in the GC gene frequency (OR = 1.17, 95%CI (1.01,1.36), P = 0.03), and the CC gene frequency (OR = 1.25, 95%CI (0.85,1.82), P = 0.26) (P > 0.01).

CONCLUSION

Our study results show that there is a significant correlation between the single nucleotide of the p53 gene and the incidence rate of female endometriosis, in which the decrease of the GG gene frequency and the increase of allele C are likely to increase the risk of such diseases.

The association between endometriosis and risk of endometrial cancer and breast cancer: a meta-analysis

PURPOSE

Endometriosis (EMS) is confirmed pathophysiologically to be an estrogen-dependent disease, similar to endometrial hyperplasia/cancer and breast cancer. Epidemiological and biological data on endometriosis might explain links between endometriosis and these cancers. We sought to identify the differences in the risk of endometrial cancer and breast cancer between women with and women without endometriosis.

METHODS

We searched PubMed, EMBASE, the Cochrane Library, and four Chinese databases (CNKI, VIP, WanFang, CBM) to identify relevant studies published online between January 2011 and March 2021. In our meta-analysis, we used the Newcastle-Ottawa Scale (NOS) to evaluate the design and quality of all studies, and we calculated the pooled risk ratio (RR) using the random model. The Q test and I2 were used to evaluate the degree of heterogeneity of eligible studies. We used funnel plots and Begg's and Egger's tests to assess publication bias.

RESULTS

Of the 1369 articles, we finally included 14 cohort studies and seven case-control studies. Data from large cohort and case-control studies indicate that women with endometriosis had an increased risk of both endometrial cancer [RR, 1.662; 95% CI, (1.148-2.407)] and breast cancer [RR, 1.082; 95% CI, (1.001-1.169)].

CONCLUSION

Endometriosis can increase the risk of endometrial cancer and breast cancer, and women with endometriosis are recommended to receive routine screening in long-term management.

LncRNA BANCR Promotes Endometrial Stromal Cell Proliferation and Invasion in Endometriosis via the miR-15a-5p/TRIM59 Axis

Long non-coding RNA (LncRNA) emerges as a regulator in various diseases, including endometriosis (EM). This study aims to uncover the role of long non-coding RNA BRAF-activated non-protein coding RNA (lncRNA BANCR)-mediated competing endogenous RNA mechanism in endometrial stromal cell (ESC) proliferation and invasion in EM by regulating miR-15a-5p/TRIM59. ESCs were isolated from eutopic and ectopic endometrial tissues, followed by the determination of Cytokeratin 19 and Vimentin expressions in cells. Then, expressions of lncRNA BANCR, microRNA (miR)-15a-5p, and tripartite motif-containing 59 (TRIM59) in tissues and cells were determined by real-time quantitative polymerase chain reaction or Western blot assay, and cell proliferation and invasion were evaluated by cell counting kit-8 and transwell assays. After that, the subcellular localization of lncRNA BANCR and binding of miR-15a-5p to lncRNA BANCR or TRIM59 were analyzed. LncRNA BANCR was upregulated in ectopic endometrial tissues and ectopic ESCs (Ect-ESCs). Silencing lncRNA BANCR suppressed Ect-ESC proliferation and invasion. LncRNA BANCR inhibited miR-15a-5p to promote TRIM59 expression. miR-15a-5p downregulation or TRIM59 overexpression both reversed the effects of silencing lncRNA BANCR on Ect-ESC proliferation and invasion. In summary, our findings suggested that lncRNA BANCR facilitated Ect-ESC proliferation and invasion by inhibiting miR-15a-5p and promoting TRIM59.

Endometriosis and irritable bowel syndrome: similarities and differences in the spectrum of comorbidities

STUDY QUESTION

Do the spectrum and prevalence of comorbidities of endometriosis and irritable bowel syndrome (IBS) overlap?

SUMMARY ANSWER

Despite several overlapping symptoms, the most significantly associated comorbidities of endometriosis and IBS are different and are rather related to the organ systems primarily involved in the index diagnosis.

WHAT IS KNOWN ALREADY

Endometriosis and IBS both have several similar unspecific symptoms, such as recurrent abdominal pain, cramping and anxiety, and both diseases affect young women and are associated with a number of comorbidities causing a poor quality of life. However, a detailed study, revealing the full spectrum of endometriosis and IBS comorbidities in the same study population, is lacking.

STUDY DESIGN, SIZE, DURATION

This article presents a retrospective in silico analysis of the data from a large nationwide biobank-based cohort consisting of 121 773 women. After excluding all first- and second-degree relatives, the data of up to 65 421 women were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

International Classification of Disease-10 diagnosis main codes associated with endometriosis (N80) and IBS (K58) diagnoses were identified from the Estonian Biobank dataset by linking with the Estonian Health Insurance Fund and other relevant registries. The associations between N80 and K58 and other diagnosis codes were tested using logistic regression, adjusting for age at recruitment and 10 genetic principal components to account for potential population stratification. Bonferroni correction was applied to account for multiple testing.

MAIN RESULTS AND THE ROLE OF CHANCE

Both women with endometriosis and IBS suffered from more conditions compared to the control group, with 226 and 428 diagnosis codes statistically significantly more frequent in women with respective diagnosis compared to controls. Women suffering from both conditions had 275 significantly associated comorbidities. A remarkable proportion of women with IBS or endometriosis suffered also from endometriosis (9.0%) or IBS (13.6%), respectively. In endometriosis, the most prevalent diagnoses were related to diseases of the genitourinary system (33 N-category codes) and in women with IBS, the most associated diagnoses were related to digestive disorders and gastrointestinal tract (52 codes from K-category). Among the most significant diagnoses in endometriosis were uterine leiomyomas (D25), menstrual disorders (N92) and infertility (N97) (P < 1 × 10-315 for all), and in IBS, lactose intolerance (E73), gastritis and duodenitis (K29) and functional dyspepsia (K30) were in the top list of most significant comorbidities (P < 1 × 10-315 for all).

LIMITATIONS, REASONS FOR CAUTION

The information about the severity stages of endometriosis and subtypes of IBS was not available for analysis. The findings may not be fully extrapolated to all female populations, because all participants were from one geographic area and had good access to health services.

WIDER IMPLICATIONS OF THE FINDINGS

These findings support previous studies that have found a high prevalence of pre-selected comorbidities in women with endometriosis and IBS. However, taking into account the differences in the full spectrum of comorbidities of endometriosis and IBS may aid in diagnosing these disorders. Women and healthcare providers need to be aware that women with endometriosis are at high risks of complications during pregnancy and should be carefully monitored.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Estonian Research Council (grant PRG1076), Horizon 2020 innovation grant (ERIN, grant no. EU952516), Enterprise Estonia (grant no. EU48695), MSCA-RISE-2020 project TRENDO (grant no. 101008193) and by the European Union through the European Regional Development Fund (Projects no. 2014-2020.4.01.15-0012 and no. 2014-2020.4.01.16-0125). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Inflammatory MicroRNAs and the Pathophysiology of Endometriosis and Atherosclerosis: Common Pathways and Future Directions Towards Elucidating the Relationship

Emerging data indicates an association between endometriosis and subclinical atherosclerosis, with women with endometriosis at a higher risk for cardiovascular disease later in life. Inflammation is proposed to play a central role in the pathophysiology of both diseases and elevated levels of systemic pro-inflammatory cytokines including macrophage migration inhibitory factor (MIF), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) are well documented. However, a thorough understanding on the mediators and mechanisms which contribute to altered cytokine expression in both diseases remain poorly understood. MicroRNAs (miRNAs) are important post-transcriptional regulators of inflammatory pathways and numerous studies have reported altered circulating levels of miRNAs in both endometriosis and atherosclerosis. Potential contribution of miRNA-mediated inflammatory cascades common to the pathophysiology of both diseases has not been evaluated but could offer insight into common pathways and early manifestation relevant to both diseases which may help understand cause and effect. In this review, we discuss and summarize differentially expressed inflammatory circulating miRNAs in endometriosis subjects, compare this profile to that of circulating levels associated with atherosclerosis when possible, and then discuss mechanistic studies focusing on these miRNAs in relevant cell, tissue, and animal models. We conclude by discussing the potential utility of targeting the relevant miRNAs in the MIF-IL-6-TNF-α pathway as therapeutic options and offer insight into future studies which will help us better understand not only the role of these miRNAs in the pathophysiology of both endometriosis and atherosclerosis but also commonality between both diseases.

The effectiveness of antioxidant therapy (vitamin C) in an experimentally induced mouse model of ovarian endometriosis

Objectives:

This study investigates the therapeutic effect of vitamin C on the development of endometrial lesions and fecundity disorders in the ovarian induction model of mouse endometriosis.

Methods:

Ovarian endometriosis was surgically induced in 14 NMRI female mice (treatment group, N = 7) and (control group, N = 7). Three days after the second surgery (to assess endometriotic implant), the mice were randomized into two intervention groups: control (placebo) and treatment (50 mg/kg vitamin C every two days orally for four weeks) groups. In the oestrus phase, the mice were sacrificed. In macroscopic assessment, endometriotic implants were evaluated in size, volume, weight, growth score and adhesion score. The microscopic assessment examined the ovarian tissue (the number of antral follicles, corpus luteum and atretic follicles) and endometriotic lesion (histologic and trichrome fibrosis scores).

Results:

Post-treatment implant volume, growth score, adhesion extent score and adhesion severity score were significantly lower in the treatment group (vitamin C) in comparison with the control group (placebo) (p < 0.0001). The difference between the median weight of endometriotic implants, epithelialization of implant tissue, trichrome fibrosis scores and follicle number in the two groups (treatment and control) was statistically significant (p < 0.05). Atretic follicles were significantly decreased after vitamin C therapy (p < 0.05). Although the numbers of corpus luteum seemed to be more preserved in specimens from the control group, there was no statistical significance between the two groups’ histological scores.

Conclusion:

As a result, we may imply that vitamin C has a significant effect on reducing the induction and growth of endometrial implants, improving the fecundity function of ovaries, and consequently prevention of endometriosis-associated cancers. Further research is needed to improve targeted interventions resulting in the prevention and treatment of human endometriosis.

The High Expression of RRM2 Can Predict the Malignant Transformation of Endometriosis

INTRODUCTION

A large number of epidemiological studies have revealed that women with endometriosis (EMS) have a higher risk of developing endometriosis-associated ovarian cancer (EAOC). At present, there are few studies on predicting the malignant transformation of ovarian endometriosis (OE). The purpose of this study is to identify and verify the molecules that may be able to predict the malignant transformation of OE.

METHODS

The gene expression profiles of ovarian cancer and OE were downloaded from Gene Expression Omnibus (GEO), and a common hub gene ribonucleotide reductase M2 (RRM2) was identified. A total of 44 patients with EAOC and 44 with OE were enrolled in this study. Immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect the expression of RRM2, while the relationship between RRM2 and Ki-67 was analyzed by IHC co-localization.

RESULTS

Bioinformatics analysis showed that the expression of RRM2 was low in EMS and high in ovarian cancer. RRM2 was obviously positively expressed in eutopic endometrium (EU), ectopic endometrium (EC), and cancer tissues of EAOC patients. The IHC signal and mRNA levels of RRM2 were higher in the EC of EAOC patients compared with OE patients (P < 0.01). In addition, there was a correlation between the expression of RRM2 and Ki-67 in EC of EAOC patients (P < 0.01).

CONCLUSION

The upregulated expression of RRM2 in the EC of OE patients may indicate malignant transformation. High expression of RRM2 promotes abnormal proliferation of histiocytes. RRM2 can be used as a potential marker of malignant transformation of OE.