Serum levels of the tumour-associated trypsin inhibitor in patients with endometriosis

MicroRNAs Dysregulation as Potential Biomarkers for Early Diagnosis of Endometriosis

Endometriosis is a benign chronic disease in women that is characterized by the presence of active foci of the endometrium or endometrial tissue occurring outside of the uterus. The disease causes disabling symptoms such as pelvic pain and infertility, which negatively affect a patient's quality of life. In addition, endometriosis imposes an immense financial burden on the healthcare system. At present, laparoscopy is the gold standard for diagnosing the disease because other non-invasive diagnostic tests have less accuracy. In addition, other diagnostic tests have low accuracy. Therefore, there is an urgent need for the development of a highly sensitive, more specific, and non-invasive test for the early diagnosis of endometriosis. Numerous researchers have suggested miRNAs as potential biomarkers for endometriosis diagnosis due to their specificity and stability. However, the greatest prognostic force is the determination of several miRNAs, the expression of which varies in a given disease. Despite the identification of several miRNAs, the studies are investigatory in nature, and there is no consensus on them. In the present review, we first provide an introduction to the dysregulation of miRNAs in patients with endometriosis and the potential use of miRNAs as biomarkers in the detection of endometriosis. Then we will describe the role of the mir-200 family in endometriosis. Several studies have shown that the expression of the mir-200 family changes in endometriosis patients, suggesting that they could be used as a diagnostic biomarker and therapeutic target for endometriosis.

Diagnostic accuracy of cancer antigen 125 for endometriosis: a systematic review and meta-analysis

BACKGROUND

The development of a non-invasive and accurate diagnostic biomarker for endometriosis is urgently needed.

OBJECTIVE

Evaluate the diagnostic accuracy of serum cancer antigen 125 (CA 125) for endometriosis.

SEARCH STRATEGY

We searched EMBASE, MEDLINE, and Web of Science from inception to January 2016.

SELECTION CRITERIA

Diagnostic accuracy studies of serum CA 125 (index test) for histologically confirmed endometriosis (reference standard) were included.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, extracted study characteristics and data. Methodological quality was assessed using Quality Assessment of Comparative Diagnostic Accuracy Studies (QUADAS-2) checklist.

MAIN RESULTS

Twenty-two studies (16 cohort, six case-control), 3626 participants, were identified. Bivariate hierarchical models were used to pool accuracy data of 14 studies (2920 participants) using CA 125 ≥ 30 units/ml. Pooled specificity was 93% (95% CI 89-95%) and sensitivity 52% (95% CI 38-66%). CA 125 was significantly more sensitive for the diagnosis of moderate or severe endometriosis compared with minimal disease (63%, 95% CI 47-77% versus 24%, 95%CI 19-32%, P-value = 0.001).

CONCLUSIONS

CA 125 performs well as a rule-in test facilitating expedited diagnosis and ensuring investigation and treatment can be confidently tailored for the management of endometriosis. Unfortunately, a negative test, CA 125 < 30 units/ml, is unable to rule out endometriosis.

TWEETABLE ABSTRACT

Blood test CA 125: a rule-in test for the diagnosis of women presenting with symptoms of endometriosis.

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.

Problems with the diagnosis of endometriosis

Endometriosis is classically defined as the presence of endometrial glands and stroma in outside the uterine cavity. As the definition suggests that confirming the ectopic endometrial stroma and glands in ectopic location histopathologically should be necessary for the diagnosis of endometriosis. Therefore, this situation leads to the need for surgery like laparoscopy for diagnosis. However, this surgical diagnostic approach will not be reliable for all patients with suspected endometriosis. It seems to be an important problem that there is still no reliable clinically diagnostic method or pathognomonic clinical finding, which may allow accurate diagnosis of endometriosis without the need for surgery or histopathologic evaluation. While these clinical features are not pathognomonic for the endometriosis, they should be used as markers for creating high-risk population for endometriosis. Clinical features and the available diagnostic methods, their advantages and limitations for the endometriosis will be discussed in this article. The different options for clinical assessment, laboratory tests and imaging techniques will be summarized and the advantages and disadvantages of these methods will be evaluated. We will also discuss the gold standard definitive diagnostic options with their problematic aspects.

The Prognostic Value of Individual Adhesion Scores from the Revised American Fertility Society Classification System for Recurrent Endometriosis

PURPOSE

This study aimed to evaluate the prognostic value of each component of the revised American Fertility Society (rAFS) classification system for the first recurrence of endometriosis after conservative laparoscopy.

MATERIALS AND METHODS

As this was a retrospective cohort study, data were collected by reviewing medical records. A total of 379 women ages 18 to 49 years were included. Women who underwent conservative laparoscopy with histologic confirmation of endometriosis at Gangnam Severance Hospital between March 2003 and May 2010 were included. Individual components of the rAFS classification system as well as preoperative serum CA-125 levels were retrospectively analyzed to assess their prognostic values for recurrence of endometriosis.

RESULTS

Of 379 patients, 80 (21.2%) were found to have recurrence of endometriosis. The median duration of follow-up was 19.0 months, and the mean age at the time of surgery was 31.8±6.7 years. In endometriosis of advanced stage, younger age at the time of surgery, bilateral ovarian cysts at the time of diagnosis, a rAFS ovarian adhesion score >24, and complete cul-de-sac obliteration were independent risk factors of poor outcomes, and a rAFS ovarian adhesion score >24 had the highest risk of recurrence [hazard ratio=2.948 (95% CI: 1.116-7.789), p=0.029].

CONCLUSION

Our results suggest that of the rAFS adnexal adhesion scores, the ovarian adhesion score rather than the tubal adhesion score was associated with a significantly increased risk of recurrent endometriosis. The preoperative serum CA-125 level may be also a significant prognostic factor for recurrence, as known. However, it seemed to only have borderline significance in affecting recurrence in the current study.

Endometriosis - morphology, clinical presentations and molecular pathology

Endometriosis is found predominantly in women of childbearing age. The prevalence of endometriosis is difficult to determine accurately. Laparoscopy or surgery is required for the definitive diagnosis. The most common symptoms are dysmenorrhea, dyspareunia, and low back pain that worsen during menses. Endometriosis occurring shortly after menarche has been frequently reported. Endometriosis has been described in a few cases at the umbilicus, even without prior history of abdominal surgery. It has been described in various atypical sites such as the fallopian tubes, bowel, liver, thorax, and even in the extremities. The most commonly affected areas in decreasing order of frequency in the gastrointestinal tract are the recto-sigmoid colon, appendix, cecum, and distal ileum. The prevalence of appendiceal endometriosis is 2.8%. Malignant transformation is a well-described, although rare (<1% of cases), complication of endometriosis. Approximately 75% of these tumors arise from endometriosis of the ovary. Other less common sites include the rectovaginal septum, rectum, and sigmoid colon. Unopposed estrogens therapy may play a role in the development of such tumors. A more recent survey of 27 malignancies associated with endometriosis found that 17 (62%) were in the ovary, 3 (11%) in the vagina, 2 (7%) each in the fallopian tube or mesosalpinx, pelvic sidewall, and colon, and 1 (4%) in the parametrium. Two cases of cerebral endometriosis and a case of endometriosis presenting as a cystic mass in the cerebellar vermis has been described. Treatment for endometriosis can be expectant, medical, or surgical depending on the severity of symptoms and the patient's desire to maintain or restore fertility.

Significance of the serum CA-125 level in intrauterine insemination cycles

Objective

There are limited data regarding the significance of elevated serum CA-125 level during IUI cycles, even though it is used widely during the initial evaluation of infertile patients. The aim of this study was to investigate the prognostic value of serum CA-125 levels during IUI cycles.

Methods

Among the patients with controlled ovarian stimulation and IUI cycles at Seoul National University Hospital from Jan 2005 through Dec 2009, 92 cases with no identified endometriotic lesion, ovarian tumor, salpingeal lesion, or uterine myoma were selected. To compare the clinical characteristics between the pregnancy group and the non-pregnancy group, the Mann-Whitney U test and Fisher's exact test were used.

Results

The overall pregnancy rate was 18.5% (17/92). The pregnancy group showed a higher number of follicles 16 mm in diameter (p=0.036), endometrial thickness (p<0.001), ampules of gonadotropin (p=0.009), and higher body mass index (p=0.022) than the non-pregnancy group. No significant difference was observed in the serum CA-125 level or the proportion of patients with CA-125 exceeding 17 IU/mL between the two groups.

Conclusion

The prognostic value of serum CA-125 level among infertile patients with IUI cycles is considered limited.

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.

Endometriosis of the appendix: A diagnostic dilemma

The incidence of endometriosis of the appendix is reported to be just <1% of the total endometriosis cases. Laparoscopic visualization and diagnostic yield are of profound significance to women in whom gynecologic diseases such as endometriosis, pelvic inflammatory disease, ruptured ovarian follicles or tubal pregnancy may be the source of pain and mimic appendicitis. Therefore, lower abdominal pain in reproductive age group female must invite the attention of the surgeon or gynecologist to entertain the possibility of endometriosis since appendiceal endometriosis, while relatively uncommon in patients with endometriosis, is rare in the general population.

Usefulness and limits of CA-125 in diagnosis of endometriosis without associated ovarian endometriomas

BACKGROUND

The aim of this study was to evaluate the diagnostic significance of CA-125 for endometriosis without ovarian endometriomas.

METHODS

Preoperative serum CA-125 levels were measured in 775 consecutive women diagnosed by laparoscopy or laparotomy with endometriosis, adenomyosis, leiomyomas, or normal pelvis.

RESULTS

Receiver operating characteristic curve analysis revealed that the area under the curve for endometriosis without endometriomas was 0.788, significantly smaller than that for endometriosis with endometriomas (0.935, P < 0.05). In diagnosis of endometriosis without endometriomas, both the maximal accuracy of 78.8% and the maximal diagnostic value of 61.2% were obtained at the cutoff value of 20 U/mL. Negative predictive value was 78.0% at the cutoff value of 20 U/mL, whereas positive predictive value was 92.9% at the cutoff value of 30 U/mL. This range is clearly superior to the empirical single cutoff of 35 U/mL.

CONCLUSIONS

In the diagnosis of endometriosis without endometriomas, combined use of two cutoff values for CA-125, 20 and 30 U/mL, provides improved diagnostic performance. However, the accuracy of using only CA-125 testing for diagnosis is still limited. Serum CA-125 testing can be done during initial screenings of women with possible endometriosis.

Laboratory testing for endometriosis

BACKGROUND

Typically, endometriosis is diagnosed surgically by laparoscopy. CA-125 is the principal serum marker used in the diagnosis and management of late-stage endometriosis. The search for a body fluid marker of early stage disease has included studies of serum, peritoneal fluid (PF), and/or tissue levels of secretory proteins, cell adhesion molecules, cytokines, tumor necrosis and vascular endothelial growth factors (VEGFs), chemokines, antiendometrial antibodies, autoantibodies to oxidized lipoproteins, aromatase P-450 expression, cytokeratins, and hormone receptors. We compared the diagnostic accuracy and clinical utility of these various types of substances in the non-surgical identification of patients with endometriosis.

METHOD

We reviewed the MEDLINE database for all publications on serum, peritoneal fluid and tissue markers of endometriosis.

RESULTS

Except for serum interleukin (IL)-6 and peritoneal fluid tumor necrosis factor (TNF)-alpha levels, the diagnostic accuracy of other markers of endometriosis was either similar or worse than that of CA-125 (sensitivity 24-94%; specificity 83-93%). The diagnostic accuracy of IL-6 and TNF-alpha was 90-100% (sensitivity) and 67-89% (specificity).

CONCLUSION

CA-125 has limited diagnostic accuracy in the identification of early stage endometriosis and none of the other markers we reviewed dramatically outperformed CA-125 in this regard with the possible exception of serum IL-6 and peritoneal fluid TNF-alpha levels.

An evidence-based evaluation of endometriosis-associated infertility

Although endometriosis is associated with infertility, a clear causal relationship has yet to be established, unless adhesive disease is found. Despite this indirect association, multiple theories have been promulgated and studies are currently underway to investigate theoretic pathogenetic mechanisms. The data regarding the treatment of endometriosis-associated infertility are limited and conflicting; however, some general preliminary conclusions can be drawn. It seems that, with early-stage disease, surgical treatment increases pregnancy rates. Using the US Preventive Services Task Force classification scheme, the evidence in support of this finding is of the highest quality, or level I. Surgical treatment for moderate and severe disease also confers benefit, although the evidence in support of this treatment is of lesser quality, level II-3 by the scheme. Medical treatment, particularly if it induces an anovulatory state, has no benefit and may delay fertility. This evidence is again of the highest quality, with a classification of level I. Although assisted reproductive technologies are of benefit regarding fertility for women with endometriosis, the IVF evidence is inconclusive, with both treatments being evaluated by at least one randomized, controlled trial conferring a level I classification to the evidence. It is unclear at this time whether endometriomas have an impact on IVF outcome. The evidence consists of only a few lower-quality studies, with a classification level of II-2. Despite the haziness of current insight into the treatment of endometriosis-associated infertility, well-designed clinical trials and basic mechanistic investigations are underway in many reproductive medicine centers. As the data from these scientific inquiries emerge, clinicians will have a clearer view of effective treatment regimens for endometriosis.

Effect of an in vitro fertilization program on serum CA 125, tumor-associated trypsin inhibitor, free beta-subunit of human chorionic gonadotropin, and common alpha-subunit of glycoprotein hormones

OBJECTIVE

To investigate the impact of an IVF program on serum levels of tumor markers CA 125, tumor-associated trypsin inhibitor, free hCG beta-subunit, and free glycoprotein hormone alpha-subunit.

DESIGN

A prospective controlled clinical study.

SETTING

Outpatient university infertility clinic.

PATIENT(S)

Seventy-one infertile patients (with tubal occlusion, pelvic endometriosis, or unexplained infertility) undergoing IVF and nine control women with regular menstrual cycles.

INTERVENTION(S)

Serial blood sampling before, during, and after IVF, or during one ovulatory menstrual cycle in the controls.

MAIN OUTCOME MEASURE(S)

Serum levels of CA 125, tumor-associated trypsin inhibitor, hCG-beta, and glycoprotein hormone-alpha.

RESULT(S)

Before IVF, all tumor markers were within the normal range except for CA 125, which was elevated in patients with endometriosis. IVF led to significant increases in CA 125 and glycoprotein hormone-alpha that differed from the changes seen during normal menstrual cycles. The luteal phase increase in CA 125 correlated with levels of E(2) and P and the number of follicles. Two months after IVF, levels of CA 125 were 12% higher than levels before treatment. Tumor-associated trypsin inhibitor and hCG-beta revealed no cyclicity.

CONCLUSION(S)

An IVF regimen increased the release of CA 125 and glycoprotein hormone-alpha. The CA 125 elevation after IVF implies a persistent effect of ovarian hyperstimulation on CA 125 release.

The performance of CA-125 measurement in the detection of endometriosis: a meta-analysis

OBJECTIVE

To assess the diagnostic performance of serum CA-125 measurement in the detection of endometriosis.

DESIGN

Meta-analysis.

SETTING AND PATIENT(S)

Twenty-three studies comparing serum CA-125 levels and laparoscopically confirmed endometriosis.

INTERVENTION(S)

Serum CA-125 measurement and laparoscopy.

MAIN OUTCOME MEASURE(S)

Sensitivity and specificity of serum CA-125 measurement in the diagnosis of endometriosis with laparoscopy as the reference standard.

RESULT(S)

The estimated summary receiver operating characteristic curves showed that the performance of serum CA-125 measurement in the diagnosis of endometriosis grade I/IV is limited, whereas its performance in the diagnosis of endometriosis grade III/IV is better.

CONCLUSION(S)

Despite its limited diagnostic performance, we believe that the routine use of serum CA-125 measurement in patients with infertility might be justified. In contrast to laparoscopy, serum CA-125 measurement is an inexpensive test that is not a burden for the patient. It could identify a subgroup of patients who are more likely to benefit from early laparoscopy. Studies reporting on the mutual dependence between serum CA-125 measurement and data from the history and physical examination are needed.