Crimson clues: advancing endometriosis detection and management with novel blood biomarkers

Endometriosis is an inflammatory condition affecting approximately 10% of the female-born population. Despite its prevalence, the lack of noninvasive biomarkers has contributed to an established global diagnostic delay. The intricate pathophysiology of this enigmatic disease may leave signatures in the blood, which, when detected, can be used as noninvasive biomarkers. This review provides an update on how investigators are utilizing the established disease pathways and innovative methodologies, including genome-wide association studies, next-generation sequencing, and machine learning, to unravel the clues left in the blood to develop blood biomarkers. Many blood biomarkers show promise in the discovery phase, but because of a lack of standardized and robust methodologies, they rarely progress to the development stages. However, we are now seeing biomarkers being validated with high diagnostic accuracy and improvements in standardization protocols, providing promise for the future of endometriosis blood biomarkers.

Multicenter evaluation of blood-based biomarkers for the detection of endometriosis and adenomyosis: A prospective non-interventional study

OBJECTIVE

To evaluate blood-based biomarkers to detect endometriosis and/or adenomyosis across nine European centers (June 2014-April 2018).

METHODS

This prospective, non-interventional study assessed the diagnostic accuracy of 54 blood-based biomarker immunoassays in samples from 919 women (aged 18-45 years) with suspicion of endometriosis and/or adenomyosis versus symptomatic controls. Endometriosis was stratified by revised American Society for Reproductive Medicine stage. Symptomatic controls were "pathologic symptomatic controls" or "pathology-free symptomatic controls". The main outcome measure was receiver operating characteristic-area under the curve (ROC-AUC) and Wilcoxon P values corrected for multiple testing (q values).

RESULTS

CA-125 performed best in "all endometriosis cases" versus "all symptomatic controls" (AUC 0.645, 95% confidence interval [CI] 0.600-0.690, q < 0.001) and increased (P < 0.001) with disease stage. In "all endometriosis cases" versus "pathology-free symptomatic controls", S100-A12 performed best (AUC 0.692, 95% CI 0.614-0.769, q = 0.001) followed by CA-125 (AUC 0.649, 95% CI 0.569-0.729, q = 0.021). In "adenomyosis only cases" versus "symptomatic controls" or "pathology-free symptomatic controls", respectively, the top-performing biomarkers were sFRP-4 (AUC 0.615, 95% CI 0.551-0.678, q = 0.045) and S100-A12 (AUC 0.701, 95% CI 0.611-0.792, q = 0.004).

CONCLUSION

This study concluded that no biomarkers tested could diagnose or rule out endometriosis/adenomyosis with high certainty.

CA125 Levels in BRCA mutation carriers - a retrospective single center cohort study

BACKGROUND

Ovarian cancer screening in BRCA1/2 mutation carriers utilizes assessment of carbohydrate antigen 125 (CA125) and transvaginal ultrasound (TVU), despite low sensitivity and specificity. We evaluated the association between CA125 levels, BRCA1/2 mutation status and menopausal status to provide more information on clinical conditions that may influence CA125 levels.

METHODS

We retrospectively analyzed repeated measurements of CA125 levels and clinical data of 466 women at high risk for ovarian cancer. CA125 levels were compared between women with and without deleterious mutations in BRCA1/2. Pearson's correlation was used to determine the association between age and CA125 serum level. Differences in CA125 levels were assessed with the Mann-Whitney U test. The effect of BRCA1/2 mutation status and menopausal status on the change in CA125 levels was determined by Two-factor analysis of variance (ANOVA).

RESULTS

The CA125 serum levels of premenopausal women (median, 13.8 kU/mL; range, 9.4 - 19.5 kU/mL) were significantly higher than in postmenopausal women (median, 10.4 kU/mL; range, 7.7 - 14.0 kU/mL; p < .001). There was no significant difference in the CA125 levels of BRCA mutation carriers and non-mutation carriers across all age groups (p = .612). When investigating the combined effect of BRCA1/2 mutation and menopausal status, variance analysis revealed a significant interaction between BRCA1/2 mutation status and menopausal status on CA125 levels (p < .001). There was a significant difference between the CA125 levels of premenopausal and postmenopausal women, with a large effect in BRCA mutation carriers (p < .001, d = 1.05), whereas in non-mutation carriers there was only a small effect (p < .001, d = 0.32).

CONCLUSION

Our findings suggest that hereditary mutations in BRCA1/2 affect the decline of CA125 levels with increasing age. To prove a definite effect of this mutation on the CA125 level, prospective trials need to be conducted to define new cut-off levels of CA 125 in mutation carriers and optimize ovarian cancer screening.

Comparison of recurrence rate and risk factors in patients with focal adenomyosis with and without medical treatment after conservative surgery

OBJECTIVE

To compare the recurrence rate and risk factors between conservative surgery followed by medical treatments and conservative surgery-only in patients with focal adenomyosis.

METHODS

This retrospective study was conducted in a single teaching hospital from May 2011 to October 2016. All eligible patients were identified into three groups: surgery-only group, surgery combined with gonadotropin-releasing hormone agonist (GnRHa), and a levonorgestrel-releasing intrauterine system (LNG-IUS) group. The recurrence rate and risk factors were compared among groups using Kaplan-Meier and Cox proportional hazards analyses. Receiver operating characteristic (ROC) curve analysis was applied to determine a cut-off value for identifying recurrence-related risk factors.

RESULTS

A total of 249 postoperative patients with adenomyosis were included in the final analysis with a mean of 41 months of follow up. The recurrence rate at the long-term follow up was significantly lower in intervention groups than in the surgery-only group (P = 0.011). The Cox proportional hazards and ROC analyses showed that a menstrual cycle longer than 26 days (P = 0.026), diameter of lesions <6 cm (P = 0.030), and combination treatment using GnRHa (P = 0.039) or LNG-IUS (P = 0.007) were protective against relapse. The risk of recurrence was lower in patients with anterior (P = 0.034) or fundus (P = 0.038) adenomyosis.

CONCLUSION

Postoperative therapy using GnRHa or LNG-IUS decreases the long-term relapse rate in women undergoing conservative surgery.

The role of some inflammatory markers, cytokins and tumor markers in diagnosis of endometriosis

Endometriosis is a multifactorial disease which etiopathogenesis has not been elucidated. One of the theories of etiopathogenesis is the inflammatory theory. Aims of the study: To develop a practical non-invasive test for the diagnosis of endometriosis by examining some inflammatory markers and cytokines; to compare the highly sensitive C-reactive protein (hsCRP), cytokines (interleukin-6-IL-6 and tumor necrotizing factor alpha) and the tumor marker cancer antigen 125 (CA-125) among healthy patients and patients with endometriosis; to determine the sensitivity and specificity of each biomarker separately in the diagnosis of endometriosis and to determine their role in the diagnosis of endometriosis. Materials and methods: In a prospective study conducted at the University Clinic for Gynecology and Obstetrics, Ss. Cyril and Methodius University in Skopje, North Macedonia 138 patients were included of a reproductive age between 18-50 years (83 with diagnosis endometriosis operated laparoscopically or with laparotomy) and a control group of 55 healthy women, in a period between 01.09.2018 to 01.05.2021. Serum levels of IL-6, TNF-α, hs-CRP and tumor marker CA-125 were evaluated in both groups. Results: Serum levels of CA-125, IL-6 and TNF-α and hs-CRP were significantly higher in patients with endometriosis compared to the control group. The surface under the ROC curve (AUC) for IL-6, CA-125, hs-CRP, and TNF-α has shown that as individual markers they all have a discriminatory capacity to diagnose patients with endometriosis. Conclusions: Results obtained in our study showed statistically significantly higher serum concentrations of CA-125, IL-6 and TNF-α and hs-CRP in patients with endometriosis compared to the control group of patients. However, none of these biomarkers showed a high sensitivity for diagnosis of endometriosis. It is necessary to find a panel combination of biomarkers with a high sensitivity of about 100% that will enable early diagnosis of endometriosis.

A More Diverse Cervical Microbiome Associates with Better Clinical Outcomes in Patients with Endometriosis: A Pilot Study

Infection-induced chronic inflammation is common in patients with endometriosis. Although microbial communities in the reproductive tracts of patients have been reported, little was known about their dynamic profiles during disease progression and complication development. Microbial communities in cervical mucus were collected by cervical swabs from 10 healthy women and 23 patients, and analyzed by 16S rRNA amplicon sequencing. The abundance, ecological relationships and functional networks of microbiota were characterized according to their prevalence, clinical stages, and clinical features including deeply infiltrating endometriosis (DIE), CA125, pain score and infertility. Cervical microbiome can be altered during endometriosis development and progression with a tendency of increased Firmicutes and decreased Actinobacteria and Bacteroidetes. Distinct from vaginal microbiome, upregulation of Lactobacillus, in combination with increased Streptococcus and decreased Dialister, was frequently associated with advanced endometriosis stages, DIE, higher CA125 levels, severe pain, and infertility. Significantly, reduced richness and diversity of cervical microbiome were detected in patients with more severe clinical symptoms. Clinical treatments against infertility can partially reverse the ecological balance of microbes through remodeling nutrition metabolism and transport and cell-cell/cell-matrix interaction. This study provides a new understanding on endometriosis development and a more diverse cervical microbiome may be beneficial for patients to have better clinical outcomes.

HE4 might be a more useful tumor biomarker to detect malignancy in patients with ovarian endometrioma when malignancy is suspected

Objective

To analyze the utility of carbohydrate antigen (CA)125 and human epididymis protein 4 (HE4) to detect malignancy in women with ovarian endometriosis, when ovarian cancer is suspected and ultrasonography results are inconclusive.

Methods

Women who underwent surgery between 2015 and 2019 for ovarian endometriosis or for adnexal masses, with a final diagnosis of ovarian carcinoma (clear cell and endometrioid) were included in this retrospective study. The women were divided into three groups: ovarian endometriosis (OE), ovarian carcinoma without endometriosis (OC), and ovarian carcinoma with endometriosis (OC + E). Adnexal masses were assessed preoperatively by transvaginal ultrasonography according to the International Ovarian Tumor Analysis (IOTA) simple rules, and CA125 and HE4 blood levels were obtained.

Results

Of 208 women, 45 had malignancy, 16 in the OC + E group and 29 in the OC group. According to transvaginal ultrasonography, 13 were classified as undetermined risk of malignancy: OC group: 3, OE group: 3, and OC + E group: 7. When we compared the tumor biomarkers, significant differences in HE4 but not in CA125 levels were found between the groups.

Conclusions

When ovarian malignancy is suspected in patients with ovarian endometriosis, HE4 is a more useful tumor biomarker to diagnose OC when ultrasonography results are inconclusive.

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.

Current biomarkers for the detection of endometriosis

A clinically reliable non-invasive test for endometriosis is expected to reduce the diagnostic delay. Although varieties of biomarkers have been investigated for decades, and cancer antigen-125, cancer antigen-199, interleukin-6, and urocortin were the most studied ones among hundreds of biomarkers, no clinically reliable biomarkers have been confirmed so far. Some emerging technologies including “omics” technologies, molecular imaging techniques, and microRNAs are promising in solving these challenges, but their utility to detect endometriosis has yet to be verified. New combinations of researched indicators or other non-invasive methods and further exploration of the emerging technologies may be new targets and future research hotspots for non-invasive diagnosis of endometriosis. In conclusion, researches of biomarkers for the detection of endometriosis are still ongoing and may benefit from novel molecular biology, bioinformatics methods and a combination of more diverse monitoring methods. Though it will be a daunting task, the identification of a specific set of diagnostic biomarkers will undoubtedly improve the status of endometriosis.

Diagnostic Significance of Selected Serum Inflammatory Markers in Women with Advanced Endometriosis

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly associated with inflammatory processes. Serum concentrations of IL-1β, IL-6, hs-CRP, IgG, YKL 40 and PRL, in comparison to the well-known CA 125 levels, were studied with the aim of identifying an additional noninvasive inflammatory marker or set of markers characteristic for endometriosis. The study group included 43 women with endometriosis (E), 35 women with benign gynecological disorders but without endometriosis (NE, non-endometriosis) as a comparative group, and a control group consisting of 18 healthy subjects (C). The serum concentrations of IL-1β, IL-6, hs-CRP, YKL-40, PRL and CA 125 were significantly higher in the E group (median values: 0.41 pg/mL, 2.42 pg/mL, 2.33 mg/L, 79.30 ng/mL, 21.88 ng/mL and 68.00 U/mL, respectively) than in the control group (median values: 0.21 pg/mL, 0.98 pg/mL, 0.52 mg/L, 49.77 ng/mL, 12.08 ng/mL and 12.20 U/mL respectively), with the significance of p = 0.011, p < 0.001, p = 0.028, p = 0.005, p < 0.001 and p < 0.001, respectively. The IgG concentrations were significantly lower in the endometriosis group (median value: 1061.21 mg/dL) as compared to healthy women (median value: 1210.50 mg/dL; p = 0.025). Significant differences in concentrations of IL-6 (p = 0.040), hs-CRP (p = 0.007) and CA 125 (p < 0.001) were observed in stage III vs. stage IV of endometriosis. Significantly higher concentrations of IL-6 (p = 0.010), hs-CRP (p = 0.037) and PRL (p < 0.001) were observed in the NE group vs. the control group. Only CA 125 concentrations were significantly higher in endometriosis patients as compared to the non-endometriosis group (p < 0.001). The proposed panel of inflammatory markers, especially IL-6, PRL and CA 125, may become a useful tool to identify women with advanced endometriosis who could qualify for treatment.

Evaluation of CA125 in relation to pain symptoms among adolescents and young adult women with and without surgically-confirmed endometriosis

Endometriosis is a painful gynecologic disease affecting one in ten reproductive aged women worldwide. Few studies have correlated this symptomatology with biomarker levels among women with and without endometriosis, and no studies correlating pain with biomarker levels have been performed in young patient populations. The purpose of this study was to examine whether CA125 correlates with different types and severity of pain among adolescents and young women with and without endometriosis and assess its performance as an endometriosis biomarker among those presenting with dysmenorrhea in this young population. Reproductive-aged women with laparoscopically-confirmed endometriosis (n = 282) and controls (n = 293) who participated in The Women's Health Study: From Adolescence to Adulthood (A2A), a cohort of adolescents and young women enrolled from 2012-2018, were included in this cross-sectional analysis. Plasma CA125 values were measured using WERF EPHect compliant blood samples collected at enrollment. Average CA125 were calculated by self-reported pain type (i.e. dysmenorrhea, non-cyclic/general pelvic pain, dyspareunia), severity, and frequency in endometriosis cases and controls. Median age at blood draw was 24 years in controls and 17 years in cases, with 68% and 89% non-Hispanic white, respectively. Most endometriosis cases (95%) were rASRM stage I/II. Average CA125 values were 12.5 U/mL in controls and 12.1 U/mL in cases adjusted for age. CA125 did not differ by pain type, its severity, or frequency in endometriosis cases or controls. Among participants who reported dysmenorrhea, CA125 did not discriminate endometriosis cases from controls using cutoff of 35 U/mL (AUC = 0.51, 95%CI = 0.50-0.53). Among adolescents and young adult women, CA125 did not correlate with pain type. CA125 did not efficiently discriminate endometriosis cases from controls even when accounting for pain symptomatology. Average CA125 values were low in adolescents and young women in both endometriosis cases and controls, suggesting cautious interpretation may be needed when measuring CA125 in this population.

miR-205-5p inhibits human endometriosis progression by targeting ANGPT2 in endometrial stromal cells

BACKGROUND

miRNA expression profiles in ectopic endometrium (EC) serving as pathophysiologic genetic fingerprints contribute to determining endometriosis progression; however, the underlying molecular mechanisms remain unknown.

METHODS

miRNA microarray analysis was used to determine the expression profiling of EC fresh tissues. qRT-PCR was performed to screen miR-205-5p expression in EC tissues. The roles of miR-205-5p and its candidate target gene, angiopoietin-2 (ANGPT2), in endometriosis progression were confirmed on the basis of both in vitro and in vivo systems. miR-205-5p and ANGPT2 expression were measured by in situ hybridization and immunochemistry, and their clinical significance was statistically analysed.

RESULTS

miR-205-5p was screened as a novel suppressor of endometriosis through primary ectopic endometrial stromal cell migration, invasion, and apoptosis assay in vitro, along with endometrial-like xenograft growth and apoptosis in vivo. In addition, ANGPT2 was identified as a direct target of miR-205-5p through bioinformatic target prediction and luciferase reporter assay. Re-expression and knockdown of ANGPT2 could respectively rescue and simulate the effects induced by miR-205-5p. Importantly, the miR-205-5p-ANGPT2 axis was found to activate the ERK/AKT pathway in endometriosis. Finally, miR-205-5p and ANGPT2 expression were closely correlated with the endometriosis severity.

CONCLUSION

The newly identified miR-205-5p-ANGPT2-AKT/ERK axis illustrates the molecular mechanism of endometriosis progression and may represent a novel diagnostic biomarker and therapeutic target for disease treatment.

Circulating miRNAs as Biomarkers for Endometriosis and Endometriosis-Related Ovarian Cancer-An Overview

Early detection and accurate diagnosis are pivotal in the management of endometriosis and endometriosis-related ovarian neoplasms (ERONs), yet there is no clear common ground regarding their pathogenesis. Endometriosis is a debilitating pathology that profoundly impairs the quality of life. Although the spontaneous resolution of endometriosis is possible, studies suggest that it can be a progressive condition, and ERONs can develop. The gold standard for diagnosis remains as the invasive method of laparoscopy followed by histological confirmation. In recent years, novel biomarkers have been discovered. MicroRNAs (miRNA) represent important epigenetic modulators of gene expression and are very attractive as biomarkers due to their lower complexity, tissue specificity, and stability in bodily fluids. Several studies have advanced the possibility of miRNAs becoming potential biomarkers in endometriosis and ERONs. Our aim is to bring these studies together in order to have a better understanding of whether, how, and when miRNAs might be used as biomarkers for these pathologies.

METHODS

We selected the reviewed papers from Google Academic, PubMed, and CrossRef. A total of eight studies met the inclusion criteria.

RESULTS

MiR-200 family, miR-143, 145, miR-20a, and miR199a were the most commonly dysregulated miRNAs in endometriosis, and miR-200 family was found to be dysregulated in both ERONs and endometriosis.

CONCLUSIONS

No single miRNA was considered as a sole biomarker for this pathology. However, since the prognostic value of biomarkers is generally enhanced if more are assessed at the same time, a panel of miRNAs could be a better indicator of the disease.

Decoy receptor 3 promotes cell adhesion and enhances endometriosis development

Endometriosis is a multifactorial inflammatory disease with persistent activation of the nuclear factor-κB (NF-κB) signalling pathway. Aberrant adhesion of endometrium is the essential step in the progression of endometriosis, but the molecular mechanism of ectopic growth of endometrium is still unclear. Decoy receptor 3 (DcR3)/TNFRSF6B, a pleiotropic immunomodulator regulated by oestrogen, is able to activate focal adhesion kinase to promote cell adhesion. We found that DcR3 is upregulated in human ectopic endometrial cells via activation of the Akt-NF-κB signalling pathway, and its expression level correlates positively with that of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and homing cell adhesion molecule (HCAM; CD44). In a multivariate regression model, DcR3 expression level was the most significant parameter associated with endometriosis severity. Knockdown of DcR3 not only downregulated the expression of ICAM-1 and HCAM, but also reduced cell adhesion and migration. In vivo investigation further showed that DcR3 promoted the growth and spread of endometrium, whereas knockdown of DcR3 by lentivirus-delivered short hairpin RNA inhibited ectopic adhesion of endometrium and abrogated endometriosis progression. These observations are in support of DcR3 playing a critical role in the pathogenesis of endometriosis, and the inhibition of DcR3 expression being a promising approach for the treatment of endometriosis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Blood biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, a costly chronic disease causing pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but is expensive and carries surgical risks. Currently, there are no non-invasive or minimally invasive tests available in clinical practice to accurately diagnose endometriosis. Although other reviews have assessed the ability of blood tests to diagnose endometriosis, this is the first review to use Cochrane methods, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To evaluate blood biomarkers as replacement tests for diagnostic surgery and as triage tests to inform decisions on surgery for endometriosis. Specific objectives include:1. To provide summary estimates of the diagnostic accuracy of blood biomarkers for the diagnosis of peritoneal, ovarian and deep infiltrating pelvic endometriosis, compared to surgical diagnosis as a reference standard.2. To assess the diagnostic utility of biomarkers that could differentiate ovarian endometrioma from other ovarian masses.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. We searched CENTRAL to July 2015, MEDLINE and EMBASE to May 2015, as well as these databases to 20 April 2015: CINAHL, PsycINFO, Web of Science, LILACS, OAIster, TRIP, ClinicalTrials.gov, DARE and PubMed.

SELECTION CRITERIA

We considered published, peer-reviewed, randomised controlled or cross-sectional studies of any size, including prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE). We included studies comparing the diagnostic test accuracy of one or more blood biomarkers with the findings of surgical visualisation of endometriotic lesions.

DATA COLLECTION AND ANALYSIS

Two authors independently collected and performed a quality assessment of data from each study. For each diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis, and we calculated sensitivity and specificity estimates. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient datasets were available. The predetermined criteria for a clinically useful blood test to replace diagnostic surgery were a sensitivity of 0.94 and a specificity of 0.79 to detect endometriosis. We set the criteria for triage tests at a sensitivity of ≥ 0.95 and a specificity of ≥ 0.50, which 'rules out' the diagnosis with high accuracy if there is a negative test result (SnOUT test), or a sensitivity of ≥ 0.50 and a specificity of ≥ 0.95, which 'rules in' the diagnosis with high accuracy if there is a positive result (SpIN test).

MAIN RESULTS

We included 141 studies that involved 15,141 participants and evaluated 122 blood biomarkers. All the studies were of poor methodological quality. Studies evaluated the blood biomarkers either in a specific phase of the menstrual cycle or irrespective of the cycle phase, and they tested for them in serum, plasma or whole blood. Included women were a selected population with a high frequency of endometriosis (10% to 85%), in which surgery was indicated for endometriosis, infertility work-up or ovarian mass. Seventy studies evaluated the diagnostic performance of 47 blood biomarkers for endometriosis (44 single-marker tests and 30 combined tests of two to six blood biomarkers). These were angiogenesis/growth factors, apoptosis markers, cell adhesion molecules, high-throughput markers, hormonal markers, immune system/inflammatory markers, oxidative stress markers, microRNAs, tumour markers and other proteins. Most of these biomarkers were assessed in small individual studies, often using different cut-off thresholds, and we could only perform meta-analyses on the data sets for anti-endometrial antibodies, interleukin-6 (IL-6), cancer antigen-19.9 (CA-19.9) and CA-125. Diagnostic estimates varied significantly between studies for each of these biomarkers, and CA-125 was the only marker with sufficient data to reliably assess sources of heterogeneity.The mean sensitivities and specificities of anti-endometrial antibodies (4 studies, 759 women) were 0.81 (95% confidence interval (CI) 0.76 to 0.87) and 0.75 (95% CI 0.46 to 1.00). For IL-6, with a cut-off value of > 1.90 to 2.00 pg/ml (3 studies, 309 women), sensitivity was 0.63 (95% CI 0.52 to 0.75) and specificity was 0.69 (95% CI 0.57 to 0.82). For CA-19.9, with a cut-off value of > 37.0 IU/ml (3 studies, 330 women), sensitivity was 0.36 (95% CI 0.26 to 0.45) and specificity was 0.87 (95% CI 0.75 to 0.99).Studies assessed CA-125 at different thresholds, demonstrating the following mean sensitivities and specificities: for cut-off > 10.0 to 14.7 U/ml: 0.70 (95% CI 0.63 to 0.77) and 0.64 (95% CI 0.47 to 0.82); for cut-off > 16.0 to 17.6 U/ml: 0.56 (95% CI 0.24, 0.88) and 0.91 (95% CI 0.75, 1.00); for cut-off > 20.0 U/ml: 0.67 (95% CI 0.50 to 0.85) and 0.69 (95% CI 0.58 to 0.80); for cut-off > 25.0 to 26.0 U/ml: 0.73 (95% CI 0.67 to 0.79) and 0.70 (95% CI 0.63 to 0.77); for cut-off > 30.0 to 33.0 U/ml: 0.62 (95% CI 0.45 to 0.79) and 0.76 (95% CI 0.53 to 1.00); and for cut-off > 35.0 to 36.0 U/ml: 0.40 (95% CI 0.32 to 0.49) and 0.91 (95% CI 0.88 to 0.94).We could not statistically evaluate other biomarkers meaningfully, including biomarkers that were assessed for their ability to differentiate endometrioma from other benign ovarian cysts.Eighty-two studies evaluated 97 biomarkers that did not differentiate women with endometriosis from disease-free controls. Of these, 22 biomarkers demonstrated conflicting results, with some studies showing differential expression and others no evidence of a difference between the endometriosis and control groups.

AUTHORS' CONCLUSIONS

Of the biomarkers that were subjected to meta-analysis, none consistently met the criteria for a replacement or triage diagnostic test. A subset of blood biomarkers could prove useful either for detecting pelvic endometriosis or for differentiating ovarian endometrioma from other benign ovarian masses, but there was insufficient evidence to draw meaningful conclusions. Overall, none of the biomarkers displayed enough accuracy to be used clinically outside a research setting. We also identified blood biomarkers that demonstrated no diagnostic value in endometriosis and recommend focusing research resources on evaluating other more clinically useful biomarkers.

Serum markers for the noninvasive diagnosis of endometriosis

Endometriosis is a disease that affects millions of women worldwide and its diagnosis is still challenging. Medical history, symptoms together with imaging data may address the correct diagnosis, but the gold standard remains laparoscopic assessment with histological confirmation. The development of serum markers as diagnostic tools for endometriosis may allow a prompt and noninvasive diagnosis. Several serum biomarkers have been investigated over the years, but none of these have shown a clinical utility and nowadays the more realistic diagnostic biomarker consists in a panel of biomarkers. The recent introduction of new technologies such as genomics and proteomics may represent the future perspective of endometriosis diagnosis.

LH (Trp8Arg/Ile15Thr), LHR (insLQ) and FSHR (Asn680Ser) polymorphisms genotypic prevalence in women with endometriosis and infertility

PURPOSE

To verify if polymorphisms of LH (Trp8Arg/Ile15Thr), LH receptor (insLQ), and FSH receptor (Asn680Ser) are associated with endometriosis and infertility.

METHODS

This is a prospective case-control study. Sixty-seven patients with endometriosis and infertility (study group) and 65 healthy fertile patients (control group) were enrolled in the study between July 2010 and July 2013. All patients had their endometriosis diagnosis made or excluded by laparoscopic surgery; study group was submitted to the surgery for infertility investigation and control group for tubal ligation. Day-3 serum hormones were collected from all patients. Analysis of nucleotide mutations for LH polymorphisms (Trp8Arg and Ile15Thr), LHR polymorphism (insLQ), and FSHR polymorphism (Asn680Ser) were performed by PCR.

RESULTS

Day-3 FSH, estradiol and LH serum levels were not different between the groups, while CA-125 was higher in patients with endometriosis and infertility. All polymorphisms studied were in Hardy-Weinberg equilibrium. The prevalence of insLQ was significantly higher in patients with endometriosis and infertility (P = 0.005). Allele occurrence in control group was 0.10 versus 0.25 in infertile endometriosis group (P = 0.001). There was no difference regarding Trp8Arg/Ile15Thr (P > 0.05) and Asn680Ser (P > 0.05) prevalence between groups.

CONCLUSION

This is the first time that prevalence of insLQ was shown to be higher in patients with endometriosis and infertility than in healthy fertile patients. There was no difference in LH and FSHR polymorphisms' prevalence between groups.

Addition of MCP-1 and MIP-3β to the IL-8 appraisal in peritoneal fluid enhances the probability of identifying women with endometriosis

Chemokines have been associated with endometriosis. Our study was aimed at evaluating the levels of six chemokines--CXCL8 (IL-8), CXCL12 (SDF-1), CCL2 (MCP-1), CCL5 (RANTES), CCL19 (MIP-3β), and CCL21 (6-Ckine)--in the peritoneal fluid (PF) of patients with and controls without endometriosis by multiplexed cytokine assay. In this retrospective case-control study conducted at the Charité University Hospital, patients (n = 36) and controls (n = 27) were enrolled. The patients were separated into groups according to stage of the disease: I-II (n = 21), III-IV (n = 1 5), and according to clinical findings: peritoneal endometriosis (PE; n = 7), deep-infiltrating endometriosis (DIE) affecting the retrocervical area (n = 13) or the bowel/rectovaginal site (n = 14). The subjects were also separated according to the cycle phase: follicular (n = 14) or luteal (n = 8) and the previous use (n = 25) or not (n = 38) of hormones. PF was collected from all subjects (n = 63) consecutively during laparoscopy. The concentration of chemokines in the PF was assessed using Luminex(®) x-MAP(®) technology. Sensitivity and specificity were calculated. A model of multiple logistic regressions estimated the odds of endometriosis for each combination of the chemokines detected. We observed significantly higher concentrations of IL-8 (p < 0.001), MCP-1 (p = 0.014), and MIP-3β (p = 0.022) in the PF of women with endometriosis than in the controls. A joint evaluation revealed that elevated levels of the three chemokines had a positive endometriosis prediction value of 89.1%. The combined assessment of MCP-1, MIP-3β, and IL-8 concentration in PF improved the likelihood of identifying patients with endometriosis. Future studies should investigate this panel in peripheral blood samples.

Association of the neutrophil-to-lymphocyte ratio and CA 125 with the endometriosis score

Objective

To evaluate the association between the severity of endometriosis and the preoperative neutrophil-to-lymphocyte ratio (NLR) and serum level of cancer antigen 125 (CA 125).

Methods

Data were obtained from the medical records of 419 patients who underwent laparoscopic conservative surgery for ovarian endometrioma between April 2005 and March 2013. Each patient's preoperative complete blood count was recorded and the endometriosis score was assessed.

Results

The endometriosis score was not associated with either the NLR or the serum level of CA 125. The endometriosis score was negatively related to preoperative hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. The only positive association was between NLR and the patients' age. NLR and preoperative serum anti-Müllerian hormone level were found to be negatively related.

Conclusion

The severity of endometriosis was not associated with the serum level of CA 125 or the NLR. The presence of a negative correlation between the severity of endometriosis and red blood cell dynamics needs further investigation.

The relation between endometriosis and ovarian cancer - a review

BACKGROUND

Endometriosis is known to harbor characteristics substantiating its possible role as a precursor of ovarian cancer.

OBJECTIVE

To assess the quality of the literature regarding the association between endometriosis and ovarian cancer and to estimate the extent of this relation.

METHODS

An electronic literature search was conducted in PubMed and 1112 articles dealing with the relation between endometriosis and ovarian cancer were identified. Original articles based on case-control studies, cohort studies and cross-sectional studies were included. Studies consisting of populations with self-reported endometriosis were excluded, as were articles with fewer than 20 cases of ovarian cancer. Twenty-eight studies underwent detailed quality assessments based on the checklists developed by the Scottish Intercollegiate Guidelines Network (SIGN). Meta-analyses were conducted on selected subgroups of ovarian cancer with coexisting endometriosis.

RESULTS

None of the 28 studies was given the highest possible rating using the SIGN checklists. The risk of ovarian cancer in women with endometriosis was reported to be a standardized incidence ratio of 1.43-8.95, a rate ratio of 1.6-2.88, an odds ratio of 1.34, with a prevalence of ovarian cancer in 2.0-17.0% of women with endometriosis. Conversely, the prevalence of endometriosis in women with ovarian cancer ranged from 3.4 to 52.6%. Meta-analysis results were weakened by heterogeneity.

CONCLUSION

There is sufficient evidence to conclude that there is an increased risk of developing clear-cell and endometrioid epithelial ovarian cancer for women with histologically verified endometriosis. Nonetheless, prospective cohort studies assessing the relation between endometriosis and ovarian cancer will increase knowledge in this field.

Discovering new clinical markers in the field of glycomics

Glycosylation modifications have been reported in a number of disease states and, as a result, there is significant focus on the discovery and development of glycan-based biomarkers. Glyco-biomarkers have the potential to enhance the efficacy and efficiency of the diagnostic procedures for these diseases.

Lactobacillus gasseri OLL2809 is effective especially on the menstrual pain and dysmenorrhea in endometriosis patients: randomized, double-blind, placebo-controlled study

In this study, we evaluated the efficacy of Lactobacillus gasseri OLL2809 on endometriosis by the randomized, double-blind and placebo-controlled clinical study, especially against pain, which is one of the causative factors to decrease the quality of life. Sixty-six patients clinically diagnosed with endometriosis were enrolled in this study, 62 of which have successfully completed the trial. The tablets containing 100 mg of L. gasseri OLL2809 (active tablet, n = 29) or placebo tablets (n = 33) were ingested once a day for 12 weeks. Visual analog scale (VAS) of pain intensity at the menstrual period and verbal rating scale (VRS) of dysmenorrhea were significantly improved by the ingestion of the active tablets as compared with placebo tablets. There was no significant change of blood examination and biochemical examination of blood in the enrolled patients. Above results show that the tablet containing L. gasseri OLL2809 is effective on endometriosis, especially against menstrual pain and dysmenorrhea. Moreover, it was found that the tablet has no adverse effects. Therefore, it was suggested that the tablet containing L. gaserri OLL2809 contributes to improve the quality of life in the patients with endometriosis.

Peripheral biomarkers of endometriosis: a systematic review

BACKGROUND

Endometriosis is estimated to affect 1 in 10 women during the reproductive years. There is often delay in making the diagnosis, mainly due to the non-specific nature of the associated symptoms and the need to verify the disease surgically. A biomarker that is simple to measure could help clinicians to diagnose (or at least exclude) endometriosis; it might also allow the effects of treatment to be monitored. If effective, such a marker or panel of markers could prevent unnecessary diagnostic procedures and/or recognize treatment failure at an early stage.

METHODS

We used QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria to perform a systematic review of the literature over the last 25 years to assess critically the clinical value of all proposed biomarkers for endometriosis in serum, plasma and urine.

RESULTS

We identified over 100 putative biomarkers in publications that met the selection criteria. We were unable to identify a single biomarker or panel of biomarkers that have unequivocally been shown to be clinically useful.

CONCLUSIONS

Peripheral biomarkers show promise as diagnostic aids, but further research is necessary before they can be recommended in routine clinical care. Panels of markers may allow increased sensitivity and specificity of any diagnostic test.