Pelvic inflammatory disease is associated with ovarian cancer development in women with endometriosis: A cohort study in Taiwan

OBJECTIVE

Endometriosis and pelvic inflammatory disease are considered to be risk factors for ovarian cancer, as dysbiosis probably contributes to ovarian cancer development via chronic inflammation and immune response alteration. Therefore, we hypothesized that pelvic inflammatory disease predisposes to ovarian cancer development in women with endometriosis.

METHODS

We selected patients who were diagnosed with endometriosis or pelvic inflammatory disease between January 1, 2000 and December 31, 2015, in a 2 million longitudinal health and welfare database in Taiwan with cancer and death registries. Patients were divided into five groups: (1) those with endometriosis, (2) those with pelvic inflammatory disease, (3) those with endometriosis diagnosed before pelvic inflammatory disease, (4) those with pelvic inflammatory disease diagnosed before endometriosis, and (5) healthy women. Propensity score matching with inverse probability of treatment weighting was used to adjust for covariates across the study groups.

RESULTS

The risk of ovarian cancer was significantly higher in women with endometriosis and subsequent pelvic inflammatory disease than in those with endometriosis alone (hazard ratio 8.07; 95% confidence interval 4.53-14.37; P < 0.001). The same result was found for ovarian cancer incidence per 1000 person-years.

CONCLUSION

Our data show that pelvic inflammatory disease is associated with cancer development in women with pre-existing endometriosis.

Impact of endometriosis on risk of ovarian, endometrial and cervical cancers: a meta-analysis

PURPOSE

The risks of gynecologic cancer have not been well established in women with endometriosis. The objective of the present study was to investigate the influence of endometriosis on the risk for three gynecologic cancer (ovarian cancer, endometrial cancer and cervical cancer).

METHODS

We gathered updated evidence about the risk relationship between endometriosis and gynecologic cancers by conducting a comprehensive search of several medical literature electronic databases, including PubMed, Embase and the Cochrane Library. The design and quality of all studies were evaluated using the Newcastle-Ottawa Scale (NOS), and a random-effects model was used to calculate pooled risk ratio (RR).

RESULTS

Of the 8538 articles our search produced, we selected 25 qualified studies, including 16 cohort studies and 9 case-control studies. Patients with endometriosis had both an increased risk of ovarian cancer [RR  1.964; 95% CI (1.685, 2.290)]. The risk of endometrial cancer (EC) is not necessarily higher in patients with endometriosis [RR 1.176, 95% CI (0.878, 1.575)]. Endometriosis was not associated with an increased risk for cervical cancer (CC) [RR 0.670, 95% CI (0.537, 0.838)].

CONCLUSIONS

Patients with endometriosis need to be closely observed and rechecked regularly to prevent malignant changes.

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.

Plasma microRNAs as novel biomarkers for endometriosis and endometriosis-associated ovarian cancer

PURPOSE

Endometriosis, a largely benign, chronic inflammatory disease, is an independent risk factor for endometrioid and clear cell epithelial ovarian tumors. We aimed to identify plasma miRNAs that can be used to differentiate patients with endometriosis and ovarian cancer from healthy individuals.

EXPERIMENTAL DESIGN

We conducted a two-stage exploratory study to investigate the use of plasma miRNA profiling to differentiate between patients with endometriosis, patients with endometriosis-associated ovarian cancer (EAOC), and healthy individuals. In the first stage, using global profiling of more than 1,000 miRNAs via reverse transcriptase quantitative PCR (RT-qPCR) in a 20-patient initial screening cohort, we identified 23 candidate miRNAs, which are differentially expressed between healthy controls (n = 6), patients with endometriosis (n = 7), and patients with EAOC (n = 7) based on the fold changes. In the second stage, the 23 miRNAs were further tested in an expanded cohort (n = 88) of healthy individuals (n = 20), endometriosis (n = 33), EAOC (n = 14), and serous ovarian cancer cases (SOC; n = 21, included as controls).

RESULTS

We identified three distinct miRNA signatures with reliable differential expression between healthy individuals, patients with endometriosis, and patients with EAOC. When profiled against the control SOC category, our results revealed different miRNAs, suggesting that the identified signatures are reflective of disease-specific pathogenic mechanisms. This was further supported by the fact that the majority of miRNAs differentially expressed in human EAOCs were mirrored in a double transgenic mouse EAOC model.

CONCLUSION

Our study reports for the first time that distinct plasma miRNA expression patterns may serve as highly specific and sensitive diagnostic biomarkers to discriminate between healthy, endometriosis, and EAOC cases.

Detecting and investigating the significance of high-frequency LOH chromosome regions for endometriosis-related candidate genes

To detect the high-frequency loss of heterozygosity (LOH) chromosome regions for ectopic endometrium of ovarian endometriosis (EMs) and to investigate the significance of high-frequency LOH chromosome regions in EMs, we obtained ectopic endometrium by laser capture microdissection (LCM (22 samples)), manual capture microdissection (MCM (18 samples)), and routine dissection (14 samples), respectively. After restriction and circularization-aided rolling circle amplification (RCA-RCA), LOH was detected at 12 microsatellite (MS) loci. The frequency of LOH was 59.09% (13/22) in LCM group, 61.11% (11/18) in the MCM group and 21.43% (3/14) in the routine dissection group. The latter was significantly lower when compared with the former two (p < 0.05). In the LCM group, candidate chromosome regions 17q21.31 and 9p21.3 had LOH frequencies of 23.8 and 13.6%, respectively. The highest LOH frequency was detected at the locus AAAT2 on chromosome 17q21.31 (40%). The chromosome region with the highest frequency of LOH for ectopic endometrium was 17q21.31, especially at the AAAT2 locus, which prompted that down regulation of the candidate genes nearby the locus might be one of the mechanisms of EMs pathogenesis. LCM combined with RCA-RCA is a reliable technique for analyzing endometrial LOH at multiple MS loci. MCM combined with RCA-RCA, which provided similar results, was more cost-effective.

Expression of the human endogenous retroviruse-W envelope gene syncytin in endometriosis lesions

BACKGROUND

None of the existing theories provides a satisfactory explanation of the development of endometriosis. One hypothesis that may lead to further clarification is that the expression of specific proteins of human endogenous retroviruses (HERVs) might influence the development of endometriosis lesions. Such endogenous retroviral proteins include syncytin, coded by HERV-W, which is associated with the physiological development of the placenta during pregnancy. This study investigated the influence of HERV-W gene expression in endometriosis foci (EM) quantitatively at the RNA level.

MATERIALS AND METHODS

Specific RNA expression of syncytin (HERV-W) was investigated in various endometrial tissues from 42 patients (with normal endometrium, postmenopausal endometrium, EM, and endometrial carcinoma). RNA was isolated from the tissue samples and transcribed into DNA using reverse transcriptase polymerase chain reaction. The resulting DNA fragments were analyzed using agarose gel electrophoresis and assessed quantitatively.

RESULTS

Normalized syncytin expression was low in EM. In Histologically normal endometrium from endometriosis patients, the expression of normalized syncytin was seven times higher in comparison with the histologically normal endometrium in the control group.

CONCLUSIONS

HERV-W syncytin expression apparently does not play a role in EM. However, it may possibly influence the development of endometriosis because of increased expression in normal endometrium in endometriosis patients.

Endometriosis: the way forward

Endometriosis, a common cause of morbidity, affects 10% of women of reproductive age. In this review we focus on the new developments in pathogenesis, diagnosis and treatment options, reviewing the literature published about this enigmatic disorder over the past three years. More specifically, new theories of the pathogenesis of the syndrome of Sampson and Cullen are discussed. The new era of genomics may characterize endometriosis and transform clinical management of the disease. Literature suggesting that endometriosis may have an environmental origin is reviewed. New approaches to medical therapy of endometriosis have been developed, including the levonorgestrel-releasing intrauterine device, aromatase inhibitors, immunomodulatory drugs, angiogenesis inhibitors, selective estrogen and progesterone receptor modulators, and statins. Subfertility is another well-known result of endometriosis and often complex decisions must be made regarding management of the endometriosis patient who wishes to conceive. Laparoscopic surgery and assisted reproduction--with or without gonadotropin-releasing hormone-agonist treatment--are reviewed. Finally we speculate about new developments in the field of endometriosis in the coming three years.

Expression of human endogenous gammaretroviral sequences in endometriosis and ovarian cancer

Endogenous retroviruses (ERVs) probably originate from ancient germ cell infections by exogenous retroviruses. A high expression of retroviruses in reproductive tissue increases the risk of viral transmission to germ line cells. We therefore investigated the expression of human ERVs (HERVs) in normal endometrium, endometriosis, normal ovaries, and ovarian cancer. Four real-time PCRs (QPCRs) for HERV-E, HERV-I/T, HERV-H, and HERV-W, respectively, and an expression control gene were used. HERV-E RNA expression was significantly higher in endometriotic tissue (average, SD) than in normal endometrium (average, SD), both measured as ratios versus control gene expression and as. HERV-E and HERV-W RNA were higher in normal ovarian tissue than in ovarian cancer. This illustrates that HERV expression is not automatically higher in malignant tissues. The other HERV PCRs did not show expression patterns as distinctive as HERVE and HERV-W in the two kinds of reproductive tissue. A small number of candidate HERV-E loci from which the transcription took place were identified by sequencing of amplimers. The role of HERV-E and HERV-W in endometriosis merits further investigation.

Association between endometriosis and cancer: a comprehensive review and a critical analysis of clinical and epidemiological evidence

OBJECTIVE

This review was aimed to critically evaluate observational, cohort, and case-control studies performed so far in order to assess the association between endometriosis and malignant diseases. Based on the observations herein presented, clinical indications that might avoid physicians' mismanaging of affected patients are proposed.

METHODS

Search strategies included online searching of the MEDLINE database and hand searching of relevant publications and reviews. Additional reports were collected by systematically reviewing all references from retrieved papers.

RESULTS

Endometriosis is not associated with an increased risk of cancer in general. Data from large cohort and case-control studies indicate an increased risk of ovarian cancers in women with endometriosis. The observed effect sizes are modest varying between 1.3 and 1.9. Evidence from clinical series consistently demonstrates that the association is confined to the endometrioid/clear-cell histotypes. Available studies are characterized by several limitations, some of which potentially bias results towards the null hypothesis whereas others leading to overestimate the association. Evidence for an association with melanoma and non-Hodgkin's lymphoma is increasing but still to be verified whereas an increased risk for other gynecological cancer types is not supported.

CONCLUSIONS

Epidemiological findings on the association between endometriosis and cancer are still elusive. At present, endometriosis should not be considered a medical condition associated with a clinically relevant risk of any specific cancer. On the basis of the present findings, modifications of the standard treatment options for the disease are not justifiable.

Basal release of urokinase plasminogen activator, plasminogen activator inhibitor-1, and soluble plasminogen activator receptor from separated and cultured endometriotic and endometrial stromal and epithelial cells

OBJECTIVE

To investigate whether separated and cultured endometriotic and endometrial stromal and epithelial cells release urokinase plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and soluble plasminogen activator receptor (suPAR) antigens in vitro.

DESIGN

In vitro study.

SETTING

University hospital clinic.

PATIENT(S)

Regularly menstruating women with and without endometriosis.

INTERVENTION(S)

Tissue samples were collected at surgery performed for clinical reasons.

MAIN OUTCOME MEASURE(S)

The antigen concentrations of uPA, PAI-1, and suPAR in culture medium were assayed by enzyme-linked immunosorbent assay.

RESULT(S)

Both stromal and epithelial cells from endometriotic and endometrial tissue released the three types of antigens, but the release of PAI-1 was significantly higher from stromal cells in the three types of tissue than from epithelial cells. Furthermore, the release of PAI-1 was significantly higher from endometriotic cells than from endometrial stromal cells.

CONCLUSION(S)

This study has demonstrated the basic capacity of separated epithelial and stromal cells from all three types of tissue to release uPA, PAI-1, and suPAR without any paracrine influence, as in vivo. The higher release of PAI-1 from endometriotic stromal cells might have importance for the invasive growth.

The effectiveness of laparoscopic excision of endometriosis

PURPOSE OF REVIEW

The optimum method for the treatment of endometriosis remains unclear. This review explores recent data concerning the effectiveness of laparoscopic excision and associated therapies, to guide clinicians in their selection of the most appropriate therapeutic regimen.

RECENT FINDINGS

Large, long-term, prospective studies and a placebo-controlled, randomized, controlled trial suggest that laparoscopic excision is an effective treatment approach for patients with all stages of endometriosis. The result of such laparoscopic excision may be improved if affected bowel, bladder and other involved structures are also excised. Adjuvant therapies such as the levonorgestrel intrauterine system and pre-sacral neurectomy may further improve outcomes. Ovarian endometrioma are invaginations of the uterine cortex, and surgical stripping of this cortex removes many primordial follicles. Despite this apparent disadvantage, stripping of the capsule is associated with better subsequent pregnancy rates and lower recurrence rates than the more conservative approach of thermal ablation to the superficial cortex.

SUMMARY

Laparoscopic excision is currently the 'gold standard' approach for the management of endometriosis, and results may be improved with careful use of appropriate techniques and suitable adjuvant therapies.

Ovarian endometriosis: from pathogenesis to surgical treatment

PURPOSE OF REVIEW

This review analyzes the literature on ovarian endometrioma, examining the controversies on pathogenesis, malignant transformation and surgical therapy.

RECENT FINDINGS

Recent literature reflects the necessity of clearly defining the ethiologic and pathologic factors that determine the origin of ovarian endometriosis and explain the increase in the condition with the prospect of developing effective prevention therapy. The possibility that ovarian endometriomas undergo malignant transformation is widely reported in the literature. Recent studies underline the importance of detecting histological differences in endometriosis (hyperplasia and atypia) and several studies of molecular biology support the theory of genetic alterations interfering with malignant transformation of ovarian endometriosis.

SUMMARY

The surgical approach must take into account all this information and, when the therapy is conservative, complete excision of the disease must be laparoscopically performed without affecting the healthy ovarian tissue.

Laparoscopic mobilization of the rectosigmoid and excision of the obliterated cul-de-sac

STUDY OBJECTIVE

To evaluate the feasibility and surgical and clinical outcomes of laparoscopic excision of anterior recto-sigmoid wall endometriosis and en bloc dissection of the obliterated cul-de-sac.

DESIGN

Retrospective cohort (Canadian Task Force classification II-2).

SETTING

University-affiliated teaching hospital.

PATIENTS

Eighty-one women with infertility and/or chronic pelvic pain. Intervention. Laparoscopic excision of all endometrial implants and uterosacral ligaments, and dissection of the cul-de-sac using a horseshoe-shaped approach to mobilize, but not resect, the rectosigmoid.

MEASUREMENTS AND MAIN OUTCOMES

Eleven women (24%) had endometriomas. Cumulative pregnancy rates in 34 women with primary infertility and 12 with secondary infertility were 62% and 42%, respectively. Eighty-eight percent of 61 women with pain reported significant improvement of symptoms.

CONCLUSION

Laparoscopic excision of cul-de-sac and rectovaginal endometriosis by this approach is feasible and safe when performed by an experienced surgeon, and results in high rates of cumulative pregnancy and relief of pain. Some patient variables may give higher rates of success for pregnancy than others.

Endometriosis: novel etiopathogenetic concepts and clinical perspectives

OBJECTIVE

To discuss current ideas about therapy for endometriosis derived from new observations generated by using molecular biology techniques and in vivo animal models of disease.

METHOD(S)

The MEDLINE database was reviewed for English-language articles on new drugs that affect the endocrine or immunologic system, the possibility that endometriosis has multiple forms, and the association of endometriosis with cancer. Specific attention was given to in vivo studies in animals or humans.

CONCLUSION(S)

Among the novel potential candidate drugs, aromatase inhibitors and raloxifene should be considered for treatment of postmenopausal women with endometriosis. Notable observations have emerged from studies of immunomodulators and antiinflammatory agents in animal models of disease. These findings must be confirmed in women. The histogenesis of ovarian endometriomas is still unclear, thus limiting new experimental approaches to this form of disease. Given the low but established risk for malignant transformation of endometriosis, efforts should be directed toward identification of susceptibility loci for the disease and its potential transformation into cancer.