Cancers, infections, and endocrine diseases in women with endometriosis

Endometriosis and autoimmunity

Endometriosis is a female-specific chronic condition that affects 1 in 10 women and other individuals with a uterus worldwide with common symptoms that include pelvic pain and infertility. Reliable and effective non-invasive biomarkers for endometriosis do not exist, and therefore currently a diagnosis of endometriosis requires direct visualization of lesions at surgery. Similarly, few safe and effective management strategies exist for endometriosis, with hormonal interventions and surgery only providing temporary symptom control. The development of endometriosis involves the implantation and proliferation of ectopic endometrial cells which triggers local and systemic inflammation and fibrosis. While multiple genetic, environmental, and lifestyle factors appear to influence the natural history of endometriosis, chronic inflammation is a hallmark feature associated with development and progression of the disease. Data further shows that endometriosis commonly co-occurs with autoimmune diseases, adding evidence that immune dysfunction likely contributes to the pathogenesis of this disorder. Specific innate and adaptive immune system drivers of endometriosis remain to be identified and additional research is needed to elucidate the mechanistic underpinnings of this debilitating disease. In this narrative review, we discuss the shared biological mechanisms and plausible immune-related connections between endometriosis and autoimmunity.

Correlation between dysbiosis of vaginal microecology and endometriosis: A systematic review and meta-analysis

BACKGROUND

Endometriosis, a complex gynecological condition, involves inflammation and immune dysregulation. The vaginal microbiota, characterized by its diversity, is an integral part of the vaginal microecology-interacting with vaginal anatomy, the endocrine system, and local mucosal immunity. Imbalances in this microecology are known to precipitate various inflammatory diseases. Despite extensive research, the connection between vaginal microbiota dysbiosis and endometriosis remains a subject of debate. Our study assesses the association between vaginal microecology dysbiosis and endometriosis.

METHODS

We systematically searched major electronic databases in English, including Embase, PubMed, The Cochrane Library, MEDLINE (Ovid), BIOSIS (Ovid), China National Knowledge Infrastructure (CNKI), and Wanfang, up to August 15, 2023. Selected articles underwent screening based on predefined inclusion and exclusion criteria. Normal vaginal microecology was defined as a negative Amsel/Spiegel test or Nugent score of 0-3, or Lactobacillus predominance determined by 16S rRNA gene amplification sequencing. Deviations from this norm were classified as dysbiosis, further categorized into bacterial vaginosis (BV) and intermediate BV. Data analysis utilized Revman 5.4, with effect sizes presented as Odds Ratios (OR) and 95% Confidence Intervals (CI).

RESULTS

Out of 1081 articles, eight met the inclusion criteria. Utilizing fixed-effect models due to low heterogeneity, the analysis revealed a positive association between dysbiosis and endometriosis (OR = 1.17, 95% CI 0.81-1.70; I2 = 0%), but showed a slight negative association between normal vaginal microecology with endometriosis (OR = 0.90, 95% CI 0.55-1.46; I2 = 29%). However, the association was not significant. Subgroup and sensitivity analyses corroborated the stability of these associations.

CONCLUSION

A positive correlation exists between vaginal microecology dysbiosis and endometriosis, notably with intermediate BV. However, the mechanisms underpinning this relationship remain elusive, highlighting the need for further research to overcome limitations.

TRIAL REGISTRATION

Registration number: CRD42023445163.

Identifying therapeutic candidates for endometriosis through a transcriptomics-based drug repositioning approach

Existing medical treatments for endometriosis-related pain are often ineffective, underscoring the need for new therapeutic strategies. In this study, we applied a computational drug repurposing pipeline to stratified and unstratified disease signatures based on endometrial gene expression data to identify potential therapeutics from existing drugs, based on expression reversal. Of 3,131 unique genes differentially expressed by at least one of six endometriosis signatures, only 308 (9.8%) were in common; however, 221 out of 299 drugs identified, (73.9%) were shared. We selected fenoprofen, an uncommonly prescribed NSAID that was the top therapeutic candidate for further investigation. When testing fenoprofen in an established rat model of endometriosis, fenoprofen successfully alleviated endometriosis-associated vaginal hyperalgesia, a surrogate marker for endometriosis-related pain. These findings validate fenoprofen as a therapeutic that could be utilized more frequently for endometriosis and suggest the utility of the aforementioned computational drug repurposing approach for endometriosis.

Breast Cancer in Patients with Previous Endometriosis Showed Low Aggressive Subtype

Background and Objectives: The association between endometriosis and breast cancer still remains controversial. The aim of this study was to investigate the different subtypes of breast cancer, immunohistochemical markers, hormone receptors, and ki67 proliferation indexes in patients with and without endometriosis and/or adenomyosis. Materials and Methods: All patients with endometriosis and breast cancer were enrolled. Women with endometriosis and breast cancer (Group BC+EN+) were compared to patients with breast cancer without endometriosis (group BC+EN-) and those with endometriosis without breast cancer (group BC-EN+). General population characteristics and histological and immunohistochemical subtypes of breast cancer were compared between groups. Results: Our study included 41 cases affected by both endometriosis and/or adenomyosis and breast cancer (Group BC+EN+) that were matched (1:2) with 82 patients affected only by breast cancer (group BC+EN-) and 82 patients affected only by endometriosis and/or adenomyosis (group BC-EN+). Group BC+EN+ presented a higher percentage of ER receptor expression (83% vs. 70%, p = 0.02), as well as lower values of Ki 67% (15% vs. 24%, p < 0.0001) and HER2+ (9.8% vs. 28%, p = 0.022). These findings were more evident when comparing patients with premenopausal status, while in postmenopausal patients, this difference was no longer significant. Regarding endometriosis, no statistical differences were observed in type or specific localization of the disease among the groups with and without breast cancer. Conclusions: Patients with endometriosis presented lower aggressive breast cancer rates with higher values of ER% and lower values of Ki 67 and HER2neu+. The type and severity of endometriotic diseases seemed not to influence breast cancer occurrence.

A Novel Classification of Endometriosis Based on Clusters of Comorbidities

Endometriosis is a heterogeneous, complex, and still challenging disease, due to its epidemiological, etiological and pathogenic, diagnostic, therapeutic, and prognosis characteristics. The classification of endometriosis is contentious, and existing therapies show significant variability in their effectiveness. This study aims to capture and describe clusters of women with endometriosis based on their comorbidity. With data extracted from electronic records of primary care, this study performs a hierarchical clustering with the Ward method of women with endometriosis with a subsequent analysis of the distribution of comorbidities. Data were available for 4055 women with endometriosis, and six clusters of women were identified: cluster 1 (less comorbidity), cluster 2 (anxiety and musculoskeletal disorders), cluster 3 (type 1 allergy or immediate hypersensitivity); cluster 4 (multiple morbidities); cluster 5 (anemia and infertility); and cluster 6 (headache and migraine). Clustering aggregates similar units into similar clusters, partitioning dissimilar objects into other clusters at a progressively finer granularity-in this case, groups of women with similarities in their comorbidities. Clusters may provide a deeper insight into the multidimensionality of endometriosis and may represent diverse "endometriosis trajectories" which may be associated with specific molecular and biochemical mechanisms. Comorbidity-based clusters may be important to the scientific study of endometriosis, contributing to the clarification of its clinical complexity and variability. An awareness of those comorbidities may help elucidate the etiopathogenesis and facilitate the accurate earlier diagnosis and initiation of treatments targeted toward particular subgroups.

Impact of Hormone Replacement Therapy on Risk of Ovarian Cancer in Postmenopausal Women with De Novo Endometriosis or a History of Endometriosis

The effect of hormone replacement therapy (HRT) on the malignant transformation of postmenopausal endometriosis remains unclear. This study aimed to investigate the impact of HRT on ovarian cancer occurrence in postmenopausal women with de novo endometriosis or a history of endometriosis. A total of 10,304 women that received HRT (the HRT group) and 10,304 that did not (the control group) were selected by 1:1 matching those that met the study criteria. Incidences of ovarian cancer (0.3% in the HRT group and 0.5% in the control group) and cumulative incidence rates of ovarian cancer were similar in the two groups. The overall mean duration of HRT was 1.4 ± 2.2 years, but the duration of HRT in women with ovarian cancer was 2.2 ± 2.9 years. After adjusting for co-variables, receipt of HRT, duration of HRT, combined use of estrogen and progesterone, and tibolone were not found to be risk factors for ovarian cancer. However, the use of estrogen alone was found to be a significant risk factor for ovarian cancer (HR 2.898; 95% CI 1.251–6.715; p = 0.013). With the exception of HRT using estrogen alone, HRT did not increase the risk of ovarian cancer in postmenopausal women with a history of endometriosis or de novo endometriosis.

Transcriptome Profiling of Eutopic and Ectopic Endometrial Stromal Cells in Women with Endometriosis Based on High-Throughput Sequencing

Endometriosis is a common gynecological disease that affects approximately 5–10% of reproductive-aged women. However, the etiology and pathophysiology of endometriosis are currently unclear. The objective of this study was to identify a potential pathogenic gene of endometriosis using RNA sequencing (RNA-seq) analysis. Human endometrial stromal cells were isolated from four patients receiving surgical treatment for endometriosis during laparoscopic surgery, and RNA-seq was used to examine differentially expressed genes (DEGs) in eutopic and ectopic endometrial stromal cells. The functional significance of the differentially expressed genes was analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. A total of 1309 upregulated and 663 downregulated genes were identified through the analysis of the transcriptomes of eutopic and ectopic endometrial stromal cells. Furthermore, KEGG analysis indicated that these DEGs were mainly enriched in the PI3K-Akt signaling pathway, cytokine–cytokine receptor interaction, and MAPK signaling pathway. Our study identified differential gene expression in eutopic as compared to ectopic endometrial tissue stromal cells. We strongly believe that our findings can bring new insights into the underlying mechanisms of endometriosis. However, future research is necessary to clarify the roles of the identified genes.

Analysis of Adverse Events and Medical Errors in Long-Term Hormone Treatments for Endometriosis: A Study Based on the US Food and Drug Administration Event Reporting System

Purpose

To investigate adverse events and medical errors, as well as their possible risk factors, of combined oral contraceptives and progestins used in patients with endometriosis.

Patients and Methods

Reports between January 1, 2014 and September 30, 2021 about patients with endometriosis in US Food and Drug Administration Adverse Event Reporting System were analyzed. Disproportional analysis was performed with the Gamma-Poisson Shrinker model to detect overreported drug-event pairs. Logistic regression analysis was utilized to explore potential risk factors.

Results

There were 823 reports on long-term hormone treatments and 6247 reports on other drugs after removing duplicates, most of which were reported by consumers and were from the United States. Procedural complications and product issues were common among long-term hormone treatment users, while some other new adverse events emerged in subgroup analysis of different dosage forms of progestin. Polytherapy was negatively associated with off label use (adjusted OR = 0.47, 95% CI 0.22-0.94) and product use in unapproved indication (adjusted OR = 0.36, 95% CI 0.15-0.76) for combined oral contraceptive users. Combined oral contraceptive users aged greater than or equal to 30 were less likely to have product use issue (adjusted OR = 0.33, 95% CI 0.12-0.82) but were at higher risk of pulmonary embolism (adjusted OR = 4.04, 95% CI 1.35-17.43).

Conclusion

Long-term hormone treatment products in this study are generally safe for endometriosis, while newly detected signals need to be validated by further exploration. Patients' tolerance and fertility desire should be considered when preparing treatment plans.

Leptin Stimulates Endometriosis Development in Mouse Models

Endometriosis is a chronic inflammatory condition in women, and obesity leads to an inflammatory condition that is directly involved in the etiology of endometriosis. However, observational studies have shown an inverse correlation between endometriosis and a low body mass index (BMI). Obesity does not protect against endometriosis, and on the contrary, an increased BMI may lead to more severe forms of the disease. To determine the effect of obesity on endometriosis, diet-induced and genetically engineered obese mouse models were integrated with endometriosis mouse models with fluorescence-tagged ectopic lesions. High-fat diet-induced obese mice revealed a significant increase in endometriosis development compared with regular-diet control mice. However, obese recipient mice with leptin deficiency and leptin receptor deficiency showed suppressed endometriosis development compared with control mice. Furthermore, donor uterine tissues with leptin deficiency and leptin receptor deficiency suppressed endometriosis development compared with control donor in control recipient mice. Importantly, we revealed that aberrant high levels of leptin concentration significantly increased endometriosis development compared with vehicle treatment group in control mice with normal body weight. Our results suggest that leptin and its receptor are critical for endometriosis development.

The analysis of the prevalence of extragenital pathology in infertile women with external genital endometriosis

Background. External genital endometriosis (EGE) is often the cause of infertility, while coagulation of its foci leads to the restoration of fertility. Often, non-invasive

preoperative diagnosis of EGE is difficult. Today, the issue of laparoscopy in infertility and whether there is a need for additional indications for its implementation remains controversial. Identification of the relationship between certain extragenital diseases with EGE is promising in terms of both understanding the pathogenesis of EGE and predicting its development.

The aim. Identification of the relationship of extragenital diseases with the presence of EGE in infertile women of reproductive age.

Materials and methods. In preparation for assisted reproductive technology programs at the Vitromed Clinic, 1 132 women of reproductive age were examined from 2019 to 2021. Collection and processing of clinical and anamnestic data were carried out. The diagnosis of EGE was verified by laparoscopy with histological examination. The results were analyzed using exact test and binary logistic regression to build a model of the relationship between EGE and somatic pathology.

Results. EGE was detected in 222 patients. A number of somatic diseases were found that are most common in EGE: bowel diseases; minor cardiac maldevelopments; chronic anemia; pathology of the pancreas; chronic tonsillitis; allergy. A logistic regression model was constructed to predict the presence of EGE in patients with the indicated somatic pathology with a sensitivity of 81.53 % and a specificity of 97.25 %.

Conclusion. Identification of comorbid extragenital diseases associated with EGE in women with infertility can serve as a basis for expanding the scope of therapeutic and diagnostic measures, in particular for laparoscopy.

What is the link between endometriosis and adiposity?

Endometriosis is defined by the presence of extrauterine endometrial tissue and presents with symptoms of dysmenorrhea, chronic pelvic pain, and impaired fertility. This condition often follows a chronic progressive course with favorable recurrence, even after surgical or medical treatment. The etiology or exact pathophysiology of endometriosis remains to be clarified, although it is thought to be a complex and multifactorial disease. Prior epidemiological or population-based studies have reported several risk factors related to endometriosis, such as environmental, menstrual, habitual, and lifestyle factors. Moreover, anthropometry has been found to be significantly associated with the diagnosis of endometriosis, as a lower body mass index is associated with an elevated risk of endometriosis. Here, we review studies that have examined the association between body size and the risk of endometriosis and discuss the clinical and biological significance of the relationship between adiposity and endometriosis.

Endometriosis, Psoriasis, and Psoriatic Arthritis: A Prospective Cohort Study

Endometriosis, psoriasis, and psoriatic arthritis (PsA) are chronic inflammatory disorders whose etiologies remain poorly understood but may be correlated, as endometriosis has been associated with other inflammatory disorders. We investigated the bidirectional associations between laparoscopically confirmed endometriosis and physician-diagnosed psoriasis and PsA in the Nurses' Health Study II cohort (n = 116,429, United States, 1991-2013). We confirmed 4,112 incident cases of laparoscopically confirmed endometriosis (mean age at diagnosis = 40.3 years) and 697 validated physician-diagnosed cases of psoriasis (mean age at diagnosis = 43.6 years), 110 of which presented with concomitant PsA. A history of psoriasis with concomitant PsA was associated with a 2-fold higher risk of endometriosis (hazard ratio (HR) = 2.01, 95% CI: 1.23, 3.30); however, no association was observed between psoriasis without PsA and endometriosis risk (HR = 0.93, 95% CI: 0.68, 1.26). When endometriosis was the exposure, it was not associated with a risk of subsequent psoriasis (HR = 1.28, 95% CI: 0.95, 1.72). The risk of psoriasis with PsA was notably higher; however, the sample size was small and the confidence intervals wide (HR = 1.77, 95% CI: 0.89, 3.52). Our findings suggest that psoriasis with concomitant PsA is associated with greater risk of laparoscopically confirmed endometriosis. In addition, there was a suggestive association between endometriosis diagnosis and subsequent risk of psoriasis with PsA.

Genetic Relationship Between Endometriosis and Melanoma

Epidemiological studies have observed that risk of endometriosis is associated with history of cutaneous melanoma and vice versa. Evidence for shared biological mechanisms between the two traits is limited. The aim of this study was to investigate the genetic correlation and causal relationship between endometriosis and melanoma. Summary statistics from genome-wide association meta-analyses (GWAS) for endometriosis and melanoma were used to estimate the genetic correlation between the traits and Mendelian randomization was used to test for a causal association. When using summary statistics from separate female and male melanoma cohorts we identified a significant positive genetic correlation between melanoma in females and endometriosis (rg = 0.144, se = 0.065, p = 0.025). However, we find no evidence of a correlation between endometriosis and melanoma in males or a combined melanoma dataset. Endometriosis was not genetically correlated with skin color, red hair, childhood sunburn occasions, ease of skin tanning, or nevus count suggesting that the correlation between endometriosis and melanoma in females is unlikely to be influenced by pigmentary traits. Mendelian Randomization analyses also provided evidence for a relationship between the genetic risk of melanoma in females and endometriosis. Colocalization analysis identified 27 genomic loci jointly associated with the two diseases regions that contain different causal variants influencing each trait independently. This study provides evidence of a small genetic correlation and relationship between the genetic risk of melanoma in females and endometriosis. Genetic risk does not equate to disease occurrence and differences in the pathogenesis and age of onset of both diseases means it is unlikely that occurrence of melanoma causes endometriosis. This study instead provides evidence that having an increased genetic risk for melanoma in females is related to increased risk of endometriosis. Larger GWAS studies with increased power will be required to further investigate these associations.

Co-occurrence of immune-mediated conditions and endometriosis among adolescents and adult women

PROBLEM

Associations between immune dysfunction conditions (eg, systemic lupus erythematous, rheumatoid arthritis) and endometriosis have been observed in adult women, but not assessed among a younger population. We investigated the association between immune-mediated conditions and endometriosis among young women.

METHOD OF STUDY

This cross-sectional analysis in the Women's Health Study: From Adolescence to Adulthood included 551 participants with surgically diagnosed endometriosis (median age=19) and 652 controls without endometriosis (median age=24). Participants completed an expanded Endometriosis Phenome and Biobanking Harmonization Project questionnaire. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to investigate the associations between autoimmune/inflammatory, atopic, chronic pain/fatigue, and endocrine disorders with endometriosis, adjusting for confounders.

RESULTS

Participants with any autoimmune and/or inflammatory condition had an increased odds of co-occurring endometriosis (OR: 1.87; CI: 0.92-3.80), as did participants with allergies (OR: 1.76; CI: 1.32-2.36), asthma (OR: 1.35; CI: 0.97-1.88), chronic fatigue syndrome and/or fibromyalgia (OR: 5.81; CI: 1.89-17.9), or previous mononucleosis (OR: 1.75; CI: 1.14-2.68). Odds of endometriosis were lower among participants with eczema (OR: 0.68; CI: 0.44-1.04). We observed a positive trend between the number of immune-mediated conditions and the odds of endometriosis (p-trend=0.0002). Endocrine disorders were not associated with endometriosis.

CONCLUSIONS

Among this population of adolescents and adult women, endometriosis was more likely among participants with autoimmune and/or inflammatory diseases, allergies, asthma, previous mononucleosis infection, and chronic fatigue and/or fibromyalgia. We observed that an increasing number of immune-mediated conditions were positively associated with endometriosis risk. It is important for clinicians who care for adolescents and women with these conditions to consider endometriosis as a comorbidity.

Ibero-American Endometriosis Patient Phenome: Demographics, Obstetric-Gynecologic Traits, and Symptomatology

Background: An international collaborative study was conducted to determine the demographic and clinical profiles of Hispanic/Latinx endometriosis patients from Latin America and Spain using the Minimal Clinical Questionnaire developed by the World Endometriosis Research Foundation (WERF) Endometriosis Phenome and Biobanking Harmonization Project (EPHect). Methods: This is a cross-sectional study to collect self-reported data on demographics, lifestyle, and endometriosis symptoms of Hispanic/Latinx endometriosis patients from April 2019 to February 2020. The EPHect Minimal Clinical Questionnaire (EPQ-M) was translated into Spanish. Comprehension and length of the translated survey were assessed by Spanish-speaking women. An electronic link was distributed via social media of endometriosis patient associations from 11 Latin American countries and Spain. Descriptive statistics (frequency, means and SD, percentages, and proportions) and correlations were conducted using SPSSv26. Results: The questionnaire was completed by 1,378 participants from 23 countries; 94.6% had self-reported diagnosis of endometriosis. Diagnostic delay was 6.6 years. Most participants had higher education, private health insurance, and were employed. The most common symptoms were back/leg pain (85.4%) and fatigue (80.7%). The mean number of children was 1.5; 34.4% had miscarriages; the mean length of infertility was 3.7 years; 47.2% reported pregnancy complications. The most common hormone treatment was oral contraceptives (47.0%). The most common comorbidities were migraines (24.1%), polycystic ovary syndrome (PCOS) (22.2%), and irritable bowel syndrome (21.1%). Most participants (97.0%) experienced pelvic pain during menses; for 78.7%, pain was severe; 86.4% reported dyspareunia. The mean age of dysmenorrhea onset was 16.2 years (SD ± 6.1). Hormone treatments were underutilized, while impact was substantial. Pain catastrophizing scores were significantly correlated with pain intensity (p < 0.001). Conclusion: This is the first comprehensive effort to generate a clinical-demographic profile of Hispanic/Latinx endometriosis patients. Differences in clinical presentation compared to other cohorts included higher prevalence and severity of dysmenorrhea and dyspareunia and high levels of pain catastrophizing. Though future studies are needed to dissect the impact of race and ethnicity on pain and impact, this profile is the first step to facilitate the recognition of risk factors and diagnostic features and promote improved clinical management of this patient population. The EPHect questionnaire is an efficient tool to capture data to allow comparisons across ethnicities and geographic regions and tackle disparities in endometriosis research.

The relation between endometrioma and ovarian cancer

INTRODUCTION

The relationship between endometrioma and ovarian cancer is a topic of discussion in the field of endometriosis and to date it is still debated whether ovarian endometriosis may represent a risk factor for ovarian cancers.

EVIDENCE ACQUISITION

A literature search was carried out using Cochrane Library, EMBASE, Medline and Google Scholar up to October 2020. Primary outcome of interest was ovarian cancer incidence in patients with endometriosis. Secondary outcome was ovarian cancer prognosis in patients with endometriosis compared to patient without endometriosis.

EVIDENCE SYNTHESIS

Patients with ovarian endometriosis has a slight increase risk of developing ovarian cancer (merely 1.8%), being the general population risk for ovarian cancer 1.31%. In patient at postmenopausal age, long-lasting endometriosis, early-age diagnosis, infertility and/or infertility treatment the risk of developing ovarian cancer is higher. Endometriosis-related ovarian cancers are generally clear cell and endometrioid and are diagnosed at early stage compared to non-endometriosis related ovarian cancer.

CONCLUSIONS

The lifetime risk for ovarian cancer is low in endometriosis patients in general and higher in subgroups of patients allowing a tailored management based on patient characteristics. Endometriosis is a chronic disease negatively affecting the quality of life, nonetheless, concerns on ovarian cancer should be avoided in order to reduce the burden of the disease on women's health.

Risk of melanoma in women with endometriosis: A Scottish national cohort study

OBJECTIVE

To explore the risk of melanoma in women with endometriosis.

STUDY DESIGN

A retrospective cohort study using Scottish national population-based data was conducted. The study comprised 281,937 women with nearly 5 million person years (4,923,628) of follow up from 1981 to 2010. 17,834 women with a new surgical diagnosis of endometriosis were compared with 83,303 women with no evidence of endometriosis at laparoscopy, 162,966 women who underwent laparoscopic sterilisation and 17,834 age-matched women from the general population to determine the risk of melanoma. Cox proportional hazards regression was used to calculate crude and adjusted Hazards ratios with 95 % Confidence Intervals.

RESULTS

Women with endometriosis had a significantly higher risk of melanoma when compared to women with no evidence of endometriosis at laparoscopy (HR 1.59, 95 % CI 1.19-2.13), women who had undergone laparoscopic sterilisation (HR 1.82, 95 % CI 1.39-2.40) and age-matched women from the general population (HR 1.63, 95 % CI 1.08-2.45).

CONCLUSION

A diagnosis of endometriosis was associated with an increased risk of developing melanoma compared to those without endometriosis. These findings highlight the need for further research to explore shared pathways in the pathogenesis of the two conditions. It is important to acknowledge that the absolute increase in the risk of melanoma in women with endometriosis remains low, which should be considered when counselling women.

Investigating the expressions of miRNA-125b and TP53 in endometriosis. Does it underlie cancer-like features of endometriosis? A case-control study

BACKGROUND

Endometriosis is generally considered as a benign condition; however, there is a possibility for it to become cancerous. miR-125b is upregulated in both endometriotic tissues and serum samples of women with endometriosis but its potential targets in endometriosis are still not fully understood.

OBJECTIVE

The role of miR-125b in the regulation of TP53 expression in endometriosis was tested with a bioinformatics approach. In addition, the expression of miR-125b and TP53 in both eutopic (Eu-p) and ectopic endometrium (Ec-p) in the endometrium tissues of women with endometriosis was compared to those in the normal endometrium tissues of controls (Normal).

MATERIALS AND METHODS

In this case-control study, the Eu-p and Ec-p samples were collected from 20 women who underwent laparoscopic surgery, and the normal endometrium tissues were collected from 20 controls with no evidence of endometriosis. For bioinformatics approach, a protein-protein interaction network was constructed based on co-expressed potential targets of miR-125b. Quantitative polymerase chain reaction technique was used for the measurement of miR125b and TP53 expression.

RESULTS

Our results showed that miR-125b was significantly overexpressed in Ec-p (p-value: 0.021). In addition, there was a significant TP53 under expression in both the Ec-p and Eu-p samples compared with the Normal tissues (p-value: 0.003).

CONCLUSION

The negative correlation between miR-125b and TP53 as well as a noticeable decreased expression of TP53 in both Ec-p and Eu-p samples may be interpreted as the roles of miR-125b/TP53 axis in the pathogenesis of endometriosis. In addition, these findings and bioinformatic analyses imply a possible role of miR-125b in cancer-like features of endometriosis.

Long-term Health Consequences of Endometriosis - Pathways and Mediation by Treatment

Purpose of review

The purpose of this review is to discuss the most up to date research on endometriosis and chronic disease risk, highlighting the role treatments for endometriosis may play in these associations.

Recent findings

Previous studies have shown a consistent association between endometriosis and risk for epithelial ovarian cancer but the association with other cancers is less clear. Current research indicates that endometriosis may in be associated with risk of systemic lupus erythematosus, and potentially other autoimmune diseases. Limited evidence is also present for the association between endometriosis and cardiovascular disease and related conditions (e.g,. hypertension, hypercholesterolemia). A potential explanation for a portion of the increased risk of chronic diseases among women with endometriosis may relate to treatments for endometriosis impacting these outcomes.

Summary

Given the prevalence of endometriosis, understanding the relation between endometriosis and other chronic diseases has the potential to impact the health of many women. However, few high-quality studies with limited biases and adequate follow-up currently exist. Future multi-disciplinary research in prospective cohorts, with ample follow-up time, and detailed information on endometriosis characteristics and treatment is critical to advancing our understanding of this disease and its consequences.

Association between endometriosis and gynecological cancers: a critical review of the literature

BACKGROUND

Endometriosis is one of the most common benign gynecological diseases with an occurrence approximately 10% in reproductive age. Endometriosis has been proposed as a possible precursor of certain ovarian carcinomas such as clear cell and endometrioid ovarian carcinomas. In addition to this pathogenic link, the association with other gynecological tumors and breast cancer has been studied on an epidemiological basis in several studies.

OBJECTIVE

The aim of this review was to critically present the recent published evidence on the association of endometriosis with gynecological cancer, and with a special emphasis on ovarian cancer.

MATERIALS AND METHODS

A search for eligible studies was conducted in three electronic databases, MEDLINE, EMBASE and CINAHL, for original research in humans published in any language.

RESULTS

The present review includes studies examining the association between endometriosis and different types of gynecological cancer (i.e., 25 studies on ovarian cancer, 8 studies on breast cancer, 8 studies on endometrial cancer and 2 studies on cervical cancer).

CONCLUSION

The present literature supports the pre-existing evidence suggesting an association between ovarian cancer and endometriosis and specifically its two histologic subtypes (endometrioid and ovarian clear cell cancer). The most recent population-based epidemiological studies cannot provide a clear association between endometriosis and endometrial, cervical or breast cancer.

Disparities in healthcare services in women with endometriosis with public vs private health insurance

BACKGROUND

The goals of health disparities research are to identify facilitators and barriers to healthcare use to help eliminate health inequalities. There are few studies on disparities in healthcare access and use trends for patients with endometriosis that may lead to differences in appropriate care based on socioeconomic status.

OBJECTIVE

This retrospective, cross-sectional study was conducted to compare health services use patterns and prevalence of co-morbidities of women with endometriosis with public (government-based) vs private (purchased or provided by employer) health insurance.

STUDY DESIGN

A total of 342 deidentified datasets (171 randomly-selected cases per study group) from women with endometriosis 14-50 years old who were members of one health insurance company that provides both public and private health insurance coverage in Puerto Rico were analyzed. Patients were defined as having at least 1 endometriosis-related medical claim (ICD-9-617.xx; International Classification of Diseases, Ninth Revision, Clinical Modification) during the 3-year study period.

RESULTS

Medical service (eg, hospital, laboratory, pathology, and radiology) use trends were 3 times lower in the public vs the private sector. Women in the public sector were 3.5 times less likely to have a laparoscopy, 2.7 times more likely to be prescribed opioid/narcotics, and were the only study subjects reporting emergency department use. Obstetrics and gynecology services were used >2-fold less by women in the public (29.5%) vs the private sector (70.5%) (P=.087).

CONCLUSIONS

We report significant differences in the use trends of endometriosis-related medical services and prescriptions, indicating differences in healthcare access based on socioeconomic parameters. Our results support the development of public health programs to promote access to healthcare for patients with endometriosis irrespective of socioeconomic status and promote health disparity research in other healthcare systems.

Ultrasound Imaging in Endometriosis

Ultrasound examination is an indisputable imaging method in the diagnosis of endometriosis, as the first step in the detection, as the fundamental tool in planning the management, and as the best diagnostic instrument during surveillance of affected women. The aim of this article is to provide an update on the role of ultrasound in the detection, in the planning of medical and surgical treatment, and in the surveillance of patients with endometriosis.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

A cohort study of 49 933 women with surgically verified endometriosis: Increased incidence of breast cancer below the age of 40

INTRODUCTION

The association between endometriosis and breast cancer is unclear. We assessed the risk of breast cancer in women with surgically verified endometriosis, with special focus on the age at cancer diagnosis, time from endometriosis diagnosis and breast cancer histology.

MATERIAL AND METHODS

All women with first endometriosis-associated diagnoses occurring concomitantly with relevant surgical codes during 1987-2012 were retrieved from the Finnish Hospital Discharge Register in Finland. Breast cancers diagnosed after the endometriosis diagnosis were identified from the Finnish Cancer Registry. The Finnish female population served as the reference. The endometriosis cohort consisted of 49 933 women (23 210 cases of ovarian, 20 187 peritoneal and 2372 deep infiltrating endometriosis). The outcome measure was the standardized incidence ratio (SIR) with 95% confidence interval (95% CI) of breast cancer calculated for the whole cohort and for the subtypes of endometriosis, stratified by the age at breast cancer diagnosis, histology and time from endometriosis diagnosis.

RESULTS

The overall risk of breast cancer (1555 cases) was similar to the reference population (SIR 0.99; 95% CI 0.94-1.03), did not differ in types of endometriosis, and was similar for ductal and lobular breast cancer. However, the SIR of breast cancer was increased in the age group of 20-29 years (SIR 4.44; 95% CI 2.22-7.94) and in the age group of 30-39 years (SIR 1.28; 95% CI 1.03-1.57). The risk of in situ breast cancer (170 cases) was increased in the entire endometriosis cohort (SIR 1.25; 95% CI 1.07-1.44).

CONCLUSIONS

The overall risk of breast cancer in women with surgically verified endometriosis was similar to that of general population. However, the risk of breast cancer at young age was increased. Young women with surgically verified endometriosis represent highly symptomatic patients with more frequent surgeries and additional therapies that might also contribute to the risk of breast cancer.

The risk of extra-ovarian malignancies among women with endometriosis: A systematic literature review and meta-analysis

We conducted a meta-analysis of studies reporting on the risk of extra-ovarian malignancies among women with endometriosis. Summary relative risk (SRR) and 95% confidence intervals (CI) were calculated through random effect models. We explored causes of between-studies heterogeneity and assessed the presence of publication bias. We included 32 studies published between 1989 and 2018. We found an increased risk of endometrial (SRR 1.38, 95%CI 1.10-1.74) and thyroid cancer (SRR 1.38, 95%CI 1.17-1.63), and inverse association with cervical cancer (SRR 0.78, 95%CI 0.60-0.95). No association emerged for breast cancer (SRR 1.04, 95%CI 0.99-1.09) and melanoma (SRR 1.31, 95%CI 0.86-1.96). Between-study heterogeneity was large for breast and endometrial cancer and melanoma. Associations were generally stronger in case-control, cross-sectional, and cohort studies with internal control group, compared to cohort studies with external control group. No indication for publication bias was found. Our conclusions need to be confirmed in properly designed cohort studies with clinical confirmation of endometriosis.

Association of Pelvic Inflammatory Disease with Risk of Endometriosis: A Nationwide Cohort Study Involving 141,460 Individuals

Endometriosis occurs when endometrial tissue exists outside the uterine cavity. The presence of ectopic endometrial tissue and resultant inflammation cause serious symptoms, including chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility. Pelvic inflammatory disease is caused by the ascension of pathogenic bacteria from the vagina to the uterus, Fallopian tubes, and ovaries. The factors involved in the pathogenesis of the two conditions are not clearly understood, but recent studies have suggested that disturbances of the female reproductive tract microbiota and inflammatory processes influence the development of both diseases. Using data from the National Health Insurance Research Database (NHIRD), we conducted a study to assess the association of pelvic inflammatory disease (PID) with endometriosis. An age-matched control group including patients without PID was selected. Patients with a pre-existing diagnosis of endometriosis were excluded. This nationwide retrospective cohort study, involving a total of 141,460 patients, demonstrated that patients with PID had a three-fold increase in the risk of developing endometriosis (HR = 3.02, 95% CI = 2.85–3.2).

Nanotechnology-based drug delivery systems for control of microbial biofilms: a review

Since the dawn of civilization, it has been understood that pathogenic microorganisms cause infectious conditions in humans, which at times, may prove fatal. Among the different virulent properties of microorganisms is their ability to form biofilms, which has been directly related to the development of chronic infections with increased disease severity. A problem in the elimination of such complex structures (biofilms) is resistance to the drugs that are currently used in clinical practice, and therefore, it becomes imperative to search for new compounds that have anti-biofilm activity. In this context, nanotechnology provides secure platforms for targeted delivery of drugs to treat numerous microbial infections that are caused by biofilms. Among the many applications of such nanotechnology-based drug delivery systems is their ability to enhance the bioactive potential of therapeutic agents. The present study reports the use of important nanoparticles, such as liposomes, microemulsions, cyclodextrins, solid lipid nanoparticles, polymeric nanoparticles, and metallic nanoparticles, in controlling microbial biofilms by targeted drug delivery. Such utilization of these nanosystems has led to a better understanding of their applications and their role in combating biofilms.

The miRNA Mirage: How Close Are We to Finding a Non-Invasive Diagnostic Biomarker in Endometriosis? A Systematic Review

Background: Endometriosis is a common disorder of the reproductive age group, characterised by the presence of ectopic endometrial tissue. The disease not only causes enormous suffering to the affected women, but also brings a tremendous medical and economic burden to bear on society. There is a long lag phase between the onset and diagnosis of the disease, mainly due to its non-specific symptoms and the lack of a non-invasive test. Endometriosis can only be diagnosed invasively by laparoscopy. A specific, non-invasive test to diagnose endometriosis is an unmet clinical need. The recent discovery of microRNAs (miRNAs) as modulators of gene expression, and their stability and specificity, make them an attractive candidate biomarker. Various studies on miRNAs in endometriosis have identified their cardinal role in the pathogenesis of the disease, and have proposed them as potential biomarkers in endometriosis. Rationale/Objectives: The aims of this review were to study the role of circulatory miRNAs in endometriosis, and bring to light whether circulatory miRNAs could be potential non-invasive biomarkers to diagnose the disease. Search methods: Three databases, PubMed, EMBASE, and BIOSIS were searched, using a combination of Mesh or Emtree headings and free-text terms, to identify literature relating to circulating miRNAs in endometriosis published from 1996 to 31 December 2017. Only peer-reviewed, full-text original research articles in English were included in the current review. The studies meeting the inclusion criteria were critically assessed and checked using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool. The dysregulated miRNAs were assessed regarding the concordance between the various studies and their role in the disease. Outcomes: Nine studies were critically analysed, and 42 different miRNAs were found to be dysregulated in them, with only one common miRNA (miR-20a) differentially expressed in more than one study. miR-17-5p/20a, miR-200, miR-199a, miR-143, and miR-145 were explored for their pivotal role in the aetiopathogenesis of endometriosis. Wider implications: It is emerging that miRNAs play a central role in the pathogenesis of endometriosis and have the potential of being promising biomarkers. Circulating miRNAs as a non-invasive diagnostic tool may shorten the delay in the diagnosis of the disease, thus alleviating the suffering of women and reducing the burden on health care systems. However, despite numerous studies on circulating miRNAs in endometriosis, no single miRNA or any panel of them seems to meet the criteria of a diagnostic biomarker. The disagreement between the various studies upholds the demand of larger, well-controlled systematic validation studies with uniformity in the research approaches and involving diverse populations.

Impact of endometriosis on risk of further gynaecological surgery and cancer: a national cohort study

OBJECTIVE

To evaluate the long-term risk of further gynaecological surgery and cancer in women with endometriosis.

DESIGN

Cohort study.

SETTING

Scotland.

PARTICIPANTS

281 937 women with nearly 5 million person years (4 923 628) of follow up from 1981 to 2010.

METHODS

In this national population-based study we compared 17 834 women with a new surgical diagnosis of endometriosis with 83 303 women with no evidence of endometriosis at laparoscopy, 162 966 women who underwent laparoscopic sterilisation, and 17 834 age-matched women from the general population. Cox proportional hazards regression was used to calculate crude and adjusted hazard ratios with 95% confidence intervals.

MAIN OUTCOME MEASURES

Risk of further gynaecological surgery, number and type of repeat surgery and time to repeat surgery from the diagnosis of endometriosis. Cancer outcomes included subsequent risk of all cancer, gynaecological and non-gynaecological cancers.

RESULTS

Women with endometriosis had a significantly higher risk of further surgery when compared with women with no evidence of endometriosis at laparoscopy [hazard ratio (HR) 1.69, 95% (confidence interval) CI 1.65-1.73], women who had undergone laparoscopic sterilisation (HR 3.30, 95% CI 3.23-3.37) and age-matched women from the general population (HR 5.95, 95% CI 5.71-6.20). They also have an increased risk of ovarian cancer when compared with general population counterparts (HR 1.77, 95% CI 1.08-2.89) or those with laparoscopic sterilisation (HR 1.75, 95% CI 1.2-2.45).

CONCLUSION

Women with surgically diagnosed endometriosis face an increased risk of multiple surgery. They have a higher chance of developing ovarian cancer in comparison with the general population and women with laparoscopic sterilisation.

TWEETABLE ABSTRACT

Women with endometriosis face an increased risk of recurrent surgery and developing ovarian cancer.

Endometriosis and the risk of skin cancer: a prospective cohort study

PURPOSE

Endometriosis has been associated with an increased risk of skin melanoma. However, associations with other skin cancer types and how they compare with melanoma are unclear. Our objective was to prospectively investigate the relationships between endometriosis and risk of non-melanoma and melanoma skin cancers.

METHODS

E3N is a prospective cohort of 98,995 French women aged 40-65 years in 1990. Data on surgically confirmed endometriosis and skin cancer diagnoses were collected every 2-3 years through self-report, with skin cancer cases confirmed through pathology reports. Hazard Ratios (HR) and 95% confidence intervals (CIs) were calculated using Cox regression models.

RESULTS

Between 1990 and 2008, 535 melanoma, 247 squamous-cell carcinoma (SCC), and 1,712 basal-cell carcinoma (BCC) cases were ascertained. Endometriosis was associated with an increased overall risk of skin cancer (HR 1.28, 95% CI 1.05-1.55). When considering skin cancer type, endometriosis was associated with melanoma risk (HR 1.64, 95% CI 1.15-2.35), but not with SCC (HR 1.21, 95% CI 0.62-2.36) or BCC (HR 1.16, 95% CI 0.91-1.48) (non-melanoma skin cancers combined: HR 1.17, 95% CI 0.93-1.46), although no heterogeneity was detected across skin cancer types (Phomogeneity = 0.13).

CONCLUSION

These data support an association between a personal history of endometriosis and the risk of skin cancer and suggest that the association is strongest for melanoma.

Laparoscopically Confirmed Endometriosis and Breast Cancer in the Nurses' Health Study II

OBJECTIVE

To investigate the association between laparoscopically confirmed endometriosis and the risk of breast cancer. Previous research on endometriosis and breast cancer has reported mixed results.

METHODS

Our prospective cohort study included 116,430 women from the Nurses' Health Study II cohort followed from 1989 until 2013. Our primary analysis investigated the association between self-reported laparoscopically confirmed endometriosis and the risk of breast cancer. Breast cancer diagnosis was verified through medical records. Multivariable adjusted Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Breast cancer was further classified by menopausal status at the time of diagnosis and tumor hormone receptor status verified through tissue microarrays when available and medical records.

RESULTS

At baseline, 5,389 (5%) women reported laparoscopically confirmed endometriosis. Over 24 years of follow-up, 4,979 (3%) incident breast cancer cases were diagnosed. Women with endometriosis were not at higher risk for overall (adjusted HR 0.96, 95% CI 0.88-1.06), premenopausal (adjusted HR 1.05, 95% CI 0.89-1.23), or postmenopausal breast cancer (adjusted HR 0.93, 95% CI 0.80-1.07). However, associations varied by tumor hormone receptor status (P value, test for heterogeneity: .001), although women with endometriosis were not at increased risk of estrogen- and progesterone receptor-positive (ER+/PR+) tumors (adjusted HR 1.00, 95% CI 0.87-1.14) or ER- and PR- tumors (adjusted HR 0.90, 95% CI 0.67-1.21). Women with endometriosis reported 2.87 ER+/PR- breast cancer cases per 10,000 person-years compared with women without endometriosis (1.32/10,000 person-years), which resulted in nearly a twofold increased risk of ER+/PR- breast cancers (adjusted HR 1.90, 95% CI 1.44-2.50).

CONCLUSION

Endometriosis was not found to be associated with overall risk of breast cancer in this study; however, endometriosis was significantly associated with an increased risk of ER+/PR- breast tumors, which should be interpreted cautiously.

Trauma and endometriosis. A review. May we explain surgical phenotypes and natural history of the disease?

OBJECTIVE

The study was performed to evaluate whether trauma is an initial event of development of endometriosis.

METHOD

Using Medline database from January 1960 up to December 2014, a systematic review was made of all published studies using the keywords trauma, healing, injury, infection, hyperperistaltism, stretch and endometriosis, adenomyosis and trauma. Studies and review articles written in French and/or in English related to the topic were included and reviewed independently by two authors.

RESULTS

The role of trauma is well-established for endometriotic lesions diagnosed in surgical scars. Various traumas including delivery, uterine curettage or incision, intraperitoneal hemorrhage, or occult pelvic inflammatory diseases could be involved to explain other localizations of the disease. Many data suggested that the healing process, particularly growth factors and the associated estrogen production, may facilitate the implantation and the growth of ectopic endometrial cells. After the initial, a traumatic event, the phenotype of the disease would depend on the tissue in which the endometriotic lesion grows.

CONCLUSIONS

The present literature review may support a potential role of a trauma as an initial event of endometriosis.

A prospective study of endometriosis and risk of benign breast disease

PURPOSE

Given the altered hormonal and inflammatory environment of women with endometriosis, several studies have suggested a positive association between endometriosis and breast cancer, although findings have been mixed. This study investigates the relationship between endometriosis and benign breast disease (BBD), benign lesions that are associated with an increased risk of breast cancer.

METHODS

Among women in the Nurses' Health Study II followed from 1991-2003 (n = 76,393), we investigated the association between laparoscopically confirmed endometriosis and biopsy-confirmed BBD. Cox proportional hazard models, adjusted for a priori potential confounding factors, were used to calculate hazard ratios (HR) and 95 % confidence intervals (CI). Across follow-up, 2011 BBD biopsies were collected and centrally reviewed by study pathologists (nonproliferative = 675, proliferative = 1336). Effect modification by infertility history and use of screening mammography was investigated.

RESULTS

Endometriosis was associated with a modest increased risk of biopsy-confirmed BBD in crude and multivariable adjusted models (HR 1.20, 95 % CI 1.00-1.43). When evaluating subtypes of BBD, we did not see different associations for nonproliferative or proliferative BBD lesions, as endometriosis was associated with a modest increased risk for both (HR nonproliferative 1.15, 95 % CI 0.84-1.57; HR proliferative 1.22, 95 % CI 0.98-1.52). The association between endometriosis and proliferative BBD appeared strongest among women who had ever experienced infertility (HR 1.50, 95 % CI 1.12-2.03; P value, test for heterogeneity = 0.05). Sensitivity analyses investigating screening behaviors between those with and without endometriosis did not significantly alter results.

CONCLUSION

Endometriosis was associated with a modest increased risk of both proliferative and nonproliferative BBD, although future work should replicate this novel finding.

Endometriosis and mammographic density measurements in the Nurses' Health Study II

PURPOSE

Endometriosis and mammographic density have been hypothesized to be influenced by sex steroid hormonal exposures in adolescence and early adulthood. We investigated the association between endometriosis and mammographic density, a consistent and independent risk factor for breast cancer.

METHODS

We conducted a cross-sectional analysis among 1,581 pre- and postmenopausal women not previously diagnosed with breast cancer in the Nurses' Health Study II cohort. We measured average percent mammographic density and absolute dense and non-dense breast area using a validated computer-assisted method. Multivariable linear regression was used to estimate the association between endometriosis and mammographic density among pre- and postmenopausal women separately.

RESULTS

Among premenopausal women, average percent mammographic density was 43.1 % among women with endometriosis (n = 91) and 40.5 % among women without endometriosis (n = 1,150). Endometriosis was not associated significantly with mammographic density among premenopausal (% difference = 2.00 percentage points 95 % CI -1.33, 5.33) or among postmenopausal women (% difference = -0.89 percentage points 95 % CI -5.10, 3.33). Among premenopausal women, there was heterogeneity by BMI at age 18 (p value = 0.003), with a suggested association among those who were lean at age 18 (BMI < 20.6 kg/m(2)) (% difference = 3.74 percentage points 95 % CI -0.29, 7.78).

CONCLUSION

Endometriosis was not found to be associated with overall measurements of mammographic density.

Targeted next-generation sequencing for molecular diagnosis of endometriosis-associated ovarian cancer

Recent molecular and pathological studies suggest that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), especially of the endometrioid and clear cell subtypes. Accordingly, this study had two cardinal aims: first, to obtain mutation profiles of EAOC from Taiwanese patients; and second, to determine whether somatic mutations present in EAOC can be detected in preneoplastic lesions. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained from ten endometriosis patients with malignant transformation. Macrodissection was performed to separate four different types of cells from FFPE sections in six patients. The four types of samples included normal endometrium, ectopic endometriotic lesion, atypical endometriosis, and carcinoma. Ultra-deep (>1000×) targeted sequencing was performed on 409 cancer-related genes to identify pathogenic mutations associated with EAOC. The most frequently mutated genes were PIK3CA (6/10) and ARID1A (5/10). Other recurrently mutated genes included ETS1, MLH1, PRKDC (3/10 each), and AMER1, ARID2, BCL11A, CREBBP, ERBB2, EXT1, FANCD2, MSH6, NF1, NOTCH1, NUMA1, PDE4DIP, PPP2R1A, RNF213, and SYNE1 (2/10 each). Importantly, in five of the six patients, identical somatic mutations were detected in atypical endometriosis and tumor lesions. In two patients, genetic alterations were also detected in ectopic endometriotic lesions, indicating the presence of genetic alterations in preneoplastic lesion. Genetic analysis in preneoplastic lesions may help to identify high-risk patients at early stage of malignant transformation and also shed new light on fundamental aspects of the molecular pathogenesis of EAOC.

KEY MESSAGES

Molecular characterization of endometriosis-associated ovarian cancer genes by targeted NGS. Candidate genes predictive of malignant transformation were identified. Chromatin remodeling, PI3K-AKT-mTOR, Notch signaling, and Wnt/β-catenin pathway may promote cell malignant transformation.

Endometriosis and breast cancer: A survey of the epidemiological studies

Endometriosis is a chronic gynecological disease with a wide spectrum of clinical manifestations that affects approximately 10% of women of reproductive age. Recent reviews have demonstrated the connection between endometriosis and breast cancer, which represents the most frequently diagnosed female cancer and the most common cause of cancer-related mortality among women worldwide. The aim of this study was to conduct a survey of available published epidemiological studies indicating the association between endometriosis and breast cancer, and simultaneously to categorize the results based on the strength of the association, with the intention of the critical evaluation of the existing data. We performed a rigorous search of the PubMed/Medline database, using the key words 'endometriosis' and 'breast cancer' for all studies published in the English language until September 2015. We found 4 retrospective cohort studies, 4 case-control studies and 3 case-cohort studies that demonstrated a notable risk for developing breast cancer among women with endometriosis. By contrast, we also found 5 case-control studies, 1 prospective cohort study, 1 case-cohort study and 1 cross-sectional study that demonstrated a negative association between endometriosis and breast cancer. In conclusion, as regards the clarification of a 'robust' or 'weak' association between endometriosis and breast cancer, no definite conclusions could be drawn, due to the limited number of studies and the limitations of each of these studies. New well-designed, prospective cohort or randomized control trials with long-term follow-up are warranted in order to provide evidence-based clinical recommendations for proper counseling, screening and treatment strategies for patients with endometriosis, and hence to improve public health.

Characteristics of women with endometriosis from the USA and Puerto Rico

PURPOSE

To describe lifetime differences in clinical characteristics of women with endometriosis between the USA and Puerto Rico.

METHODS

A descriptive study using self-administered demographic and clinical questionnaires was undertaken. Women with self-reported surgically diagnosed endometriosis who completed questionnaires from the Endometriosis Association (EA), Wisconsin, USA (n = 4358) and the Endometriosis Research Program (ERP) in Puerto Rico (n = 878), were included in this study. We compared demographic, gynecological and clinical history, frequency of endometriosis-associated symptoms and co-morbidities.

RESULTS

Although both groups have similar symptomatology, EA respondents had significantly higher rates of chronic pelvic pain and incapacitating pain than ERP participants. EA respondents were significantly more likely to report a history of problems getting pregnant, heavy bleeding, and hysterectomy than ERP respondents. Miscarriages were more frequently reported by the ERP group. Co-morbidities such as allergies, chronic fatigue syndrome, and fibromyalgia were more prevalent in EA respondents, whereas asthma was significantly more frequent in participants from ERP.

CONCLUSIONS

Overall, women with endometriosis from the USA and Puerto Rico reported high rates of pain and infertility and a similar spectrum of symptoms. Those from the EA reported longer time to diagnosis, and diagnostic delays than those from the ERP, which may explain the observed increased in rates of endometriosis-related symptoms and co-morbidities in EA as compared to ERP.

Association of endometriosis and breast cancer: mini review of the literature

BACKGROUND

Endometriosis is a common, estrogen-dependent, gynecological disease, which is defined as the presence of endometrial tissue outside the uterine cavity. Current data have associated endometriosis with specific malignancies, including ovarian and breast cancer.

PURPOSE

The purpose of our study is to summarize and present published literature providing evidence regarding the possible relationship between endometriosis and breast cancer.

METHODS

Pubmed and Scopus databases were searched systematically for studies that sought to identify a potential association of endometriosis and breast cancer. 15 relevant articles were retrieved and included in the present review.

RESULTS

A small number of observational studies have shown a correlation of endometriosis and breast cancer. Other studies found that the risk of breast cancer increases with age. The scenario of an early interruption of the inflammatory process, derived from endometriosis, by oophorectomy and a possible consequent decrease in the risk of breast cancer has also been proposed. The hypothesis that both conditions could be related through common mutations on BRAC1 and BRAC2 genes has also been investigated.

CONCLUSION

The available published evidence is inconclusive. Further studies are needed to evaluate the association of endometriosis and breast cancer and the possible pathogenetic pathways that relate the two disorders.

Endometriosis: a high-risk population for major chronic diseases?

BACKGROUND

Despite an estimated prevalence of 10% in women, the etiology of endometriosis remains poorly understood. Over recent decades, endometriosis has been associated with risk of several chronic diseases, such as cancer, autoimmune diseases, asthma/atopic diseases and cardiovascular diseases. A deeper understanding of these associations is needed as they may provide new leads into the causes or consequences of endometriosis. This review summarizes the available epidemiological findings on the associations between endometriosis and other chronic diseases and discusses hypotheses for underlying mechanisms, potential sources of bias and methodological complexities.

METHODS

We performed a comprehensive search of the PubMed/Medline and ISI Web of Knowledge databases for all studies reporting on the associations between endometriosis and other diseases published in English through to May 2014, using numerous search terms. We additionally examined the reference lists of all identified papers to capture any additional articles that were not identified through computer searches.

RESULTS

We identified 21 studies on the associations between endometriosis and ovarian cancer, 14 for breast cancer, 8 for endometrial cancer, 4 for cervical cancer, 12 for cutaneous melanoma and 3 for non-Hodgkin's lymphoma, as well as 9 on the links between endometriosis and autoimmune diseases, 6 on the links with asthma and atopic diseases, and 4 on the links with cardiovascular diseases. Endometriosis patients were reported to be at higher risk of ovarian and breast cancers, cutaneous melanoma, asthma, and some autoimmune, cardiovascular and atopic diseases, and at decreased risk of cervical cancer.

CONCLUSIONS

Increasing evidence suggests that endometriosis patients are at higher risk of several chronic diseases. Although the underlying mechanisms are not yet understood, the available data to date suggest that endometriosis is not harmless with respects to women's long-term health. If these relationships are confirmed, these findings may have important implications in screening practices and in the management and care of endometriosis patients.

The Impact of Endometriosis across the Lifespan of Women: Foreseeable Research and Therapeutic Prospects

In addition to estrogen dependence, endometriosis is characterized by chronic pelvic inflammation. The impact of the chronic pelvic inflammatory state on other organ systems and women's health is unclear. Endometriosis associated chronic inflammation and potential adverse health effects across the lifespan render it imperative for renewed research vigor into the identification of novel biomarkers of disease and therapeutic options. Herein we propose a number of opportunities for research and development of new therapeutics to address the unmet needs in the treatment of endometriosis per se and its ancillary risks for other diseases in women across the lifespan.

Novel insights on the malignant transformation of endometriosis into ovarian carcinoma

The malignant transformation of endometriosis is an uncommon event, which happens in 0.7-2.5% of the cases, and, when occurs, it usually involves the ovary. A 2 to 3-fold higher risk of ovarian endometrioid and clear cell carcinoma has been reported in women with endometriosis. Pathological studies have detected a morphological continuum of sequential steps from normal endometriotic cyst epithelium to atypical endometriosis and finally to invasive carcinoma. Ovarian endometrioid carcinoma harbors mutations of CTNNB1 in 16-53.3%, of PTEN in 14-20% and of ARID1A in 30-55% of the cases. Ovarian clear cell carcinoma harbors mutations of PIK3CA in 20-40% and of ARID1 in 15-75% of the cases. Whereas estrogen receptors and progesterone receptors are quite always absent, HNF-1b is often over-expressed in this histotype. Atypical endometriosis and endometriosis-related ovarian neoplasms share molecular alterations, such as PTEN mutations, ARID1A mutations and up-regulation of HNF-1b. Moreover, ARID1A mutations have been noted in clear cell tumors and contiguous atypical endometriosis, but not in distant endometriotic lesions. The loss of BAF250a protein expression is suggestive for the presence of ARID1A mutations, and represents an useful marker of malignant transformation of endometriosis.

ABO and Rhesus blood groups and risk of endometriosis in a French Caucasian population of 633 patients living in the same geographic area

Objectives. The identification of epidemiological factors increasing the risk of endometriosis could shorten the time to diagnosis. Specific blood groups may be more common in patients with endometriosis. Study Design. We designed a cross-sectional study of 633 Caucasian women living in the same geographic area. Study group included 311 patients with histologically proven endometriosis. Control group included 322 patients without endometriosis as checked during surgery. Frequencies of ABO and Rhesus groups in the study and control groups were compared using univariate and multivariate analyses. Results. We observed a higher proportion of Rh-negative women in the study group, as compared to healthy controls. Multivariate analysis showed that Rh-negative women are twice as likely to develop endometriosis (aOR = 1.90; 95% CI: 1.20–2.90). There was no significant difference in ABO group distribution between patients and controls. There was no difference when taking into account either the clinical forms (superficial endometriosis, endometrioma, and deep infiltration endometriosis) or the rAFS stages. Conclusion. Rh-negative women are twice as likely to develop endometriosis. Chromosome 1p, which contains the genes coding for the Rhesus, could also harbor endometriosis susceptibility genes.

Endometriosis and ovarian cancer risk: a systematic review of epidemiological studies

Background: A possible etiological association between endometriosis and ovarian cancer has been repeatedly reported in the literature.

Objective: Our aim was to evaluate published epidemiological data on this issue.

Review Methods: We conducted an extensive search of the literature in MEDLINE, of articles ever published until February 2014, using the key-words “endometriosis” and “ovarian” and one of the following terms in the title: “cancer” or “malignancy” or “malignant” or “tumor” or “neoplasia” or “neoplasm” or “transformation.” Retrieved papers were checked for further relevant publications.

Results: Overall, our search yielded 1 prospective cohort study, 10 retrospective cohort, and 5 case–control studies. A meta-analysis of these studies was not considered to be appropriate, due to differences in data reporting, study design, and adjustment for confounding factors.

Limitations: The main limitation of studies found, with one exception, was the lack of operative confirmation of endometriosis.

Conclusion: An association of endometriosis with clear-cell and endometrioid ovarian cancer was a consistent finding in most studies. On the other hand, existing epidemiological evidence linking endometriosis with ovarian cancer is insufficient to change current clinical practice. Prospective cohort studies, with prior laparoscopic confirmation, localization, and staging of endometriosis are needed, in order to further clarify this issue.

Krüppel-like factor 9 deficiency in uterine endometrial cells promotes ectopic lesion establishment associated with activated notch and hedgehog signaling in a mouse model of endometriosis

Endometriosis, a steroid hormone-dependent disease characterized by aberrant activation of estrogen receptor signaling and progesterone resistance, remains intractable because of the complexity of the pathways underlying its manifestation. We previously showed that eutopic endometria of women with endometriosis exhibit lower expression of Krüppel-like factor 9 (KLF9), a progesterone receptor coregulator in the uterus, relative to that of women without disease. Here we examined whether loss of endometrial KLF9 expression causes ectopic lesion establishment using syngeneic wild-type (WT) mice as recipients of endometrial fragments from WT and Klf9 null donors. We found significantly higher incidence of ectopic lesions with Klf9 null than WT endometria 8 weeks after tissue injection into the intraperitoneal cavity. The increased incidence of lesion establishment with Klf9 null endometria was associated with a higher expression ratio of estrogen receptor 2 isoform relative to that of estrogen receptor 1 and attenuated progesterone receptor levels in endometriotic stromal cells. PCR array analyses of Notch and Hedgehog signaling components in ectopic lesions demonstrated up-regulated expression of select genes (Jag 2, Shh, Gli1, and Stil 1) in Klf9 null lesions relative to that in WT lesions. Immunohistochemical analyses showed increased levels of Notch intracellular domain and Sonic Hedgehog proteins in Klf9 null lesions relative to that in WT lesions, confirming pathway activation. WT recipients with Klf9 null lesions displayed lower systemic levels of TNFα and IL-6 and higher soluble TNF receptor 1 than corresponding recipients with WT lesions. Our results suggest that endometrial KLF9 deficiency promotes endometriotic lesion establishment by the coincident deregulation of Notch-, Hedgehog-, and steroid receptor-regulated pathways.

Tissue and circulating microRNA influence reproductive function in endometrial disease

microRNA (miRNA) have emerged as important epigenetic modulators of gene expression in diverse pathological and physiological processes. In the endometrium, miRNA appear to have a role in the dynamic changes associated with the menstrual cycle, in implantation and in the pathophysiology associated with reproductive disorders such as recurrent miscarriage and endometriosis. This review explores the role of miRNA in endometrial physiology and endometrial disorders of reproduction and also raises the prospect that circulating miRNA may modulate endometrial function or reflect disordered endometrial activity. The clinical potential to use miRNA in diagnostic tests of endometrial function or in the treatment of endometrial disorders will also be discussed.