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

The "Road" to Malignant Transformation from Endometriosis to Endometriosis-Associated Ovarian Cancers (EAOCs): An mTOR-Centred Review

Ovarian cancer is an umbrella term covering a number of distinct subtypes. Endometrioid and clear-cell ovarian carcinoma are endometriosis-associated ovarian cancers (EAOCs) frequently arising from ectopic endometrium in the ovary. The mechanistic target of rapamycin (mTOR) is a crucial regulator of cellular homeostasis and is dysregulated in both endometriosis and endometriosis-associated ovarian cancer, potentially favouring carcinogenesis across a spectrum from benign disease with cancer-like characteristics, through an atypical phase, to frank malignancy. In this review, we focus on mTOR dysregulation in endometriosis and EAOCs, investigating cancer driver gene mutations and their potential interaction with the mTOR pathway. Additionally, we explore the complex pathogenesis of transformation, considering environmental, hormonal, and epigenetic factors. We then discuss postmenopausal endometriosis pathogenesis and propensity for malignant transformation. Finally, we summarize the current advancements in mTOR-targeted therapeutics for endometriosis and EAOCs.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Construction and validation of prognostic nomogram and clinical characteristics for ovarian endometrioid carcinoma: an SEER-based cohort study

BACKGROUND

Ovarian endometrioid carcinoma (OEC) is the second most commonly occurring ovarian epithelial malignancy, but the associated prognostic factors remain obscure. This study aimed to analyze independent prognostic factors for patients with OEC and to develop and validate a nomogram to predict the overall survival (OS) of these patients.

METHODS

Clinical information of patients with OEC (2000-2019) was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox analyses were used to identify independent prognostic factors, and nomogram models were constructed using independent prognostic factors. Receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA) were used to verify the accuracy and validity of the nomogram. Kaplan-Meier curves were used to compare the differences in OS and cancer-specific survival (CSS) among subgroups.

RESULTS

A total of 4628 patients with OEC were included, being divided into training (n = 3238) and validation (n = 1390) sets (7:3 ratio). On multivariate Cox analysis, AJCC stage, age, tumor size, differentiation, chemotherapy, and lymph node resection were significant predictors of survival outcomes (P < 0.05). Resection of 1-3 lymph nodes in early-stage OEC patients did not significantly prolong OS (P > 0.05), but resection of ≥ 4 lymph nodes in early-stage improved OS and CSS (P < 0.05). The OS of early-stage patients was not related to whether or not they received chemotherapy (P > 0.05). Lymph node resection and chemotherapy significantly improved the prognosis of patients with advanced OEC (P < 0.05). The c-index of nomogram prediction model was 0.782. ROC with good discrimination, calibration plots with high consistency, and DCA with large net benefit rate result in large clinical value.

CONCLUSION

AJCC stage, differentiation, tumor size, age, chemotherapy, and lymph node dissection were prognostic factors of OEC. The constructed nomogram prediction model can effectively predict the prognosis of OEC patients and improve the accuracy of clinical decision-making.

Investigating the relationship between breast and gynecological cancers and infertility and its treatments: a case-control study

OBJECTIVE

Due to the high prevalence of breast and gynecological cancers among women, it is crucial to identify the risk factors of these cancers. Thus, the present study aimed to evaluate the relationship between breast and gynecological cancers and infertility and its treatments in women suffering from these cancers.

METHODS

This case-control study was conducted with the participation of 400 people (200 women with breast and gynecological cancers and 200 healthy women without a history of cancer) in hospitals and health centers in Tabriz, Iran, in 2022. Data were collected using a four-part researcher-made questionnaire including sociodemographic characteristics, obstetric characteristics, information related to cancer, and information related to infertility and its treatments.

RESULT

s Based on the multivariable logistic regression model and by controlling sociodemographic and obstetric characteristics as possible confounding variables, women with cancer had an infertility history almost four times more than women who did not have a history of cancer (OR = 3.56; 95% CI: 1.36-9.33; P = 0.010). Women with breast cancer had an infertility history five times more than women without a history of breast cancer (OR = 5.11; 95% CI: 1.68-15.50; P = 0.004). The infertility history of women with gynecological cancer was more than three times that of the control group. However, there was no statistically significant difference between the two groups (OR = 3.36; 95% CI: 0.99-11.47; P = 0.053).

CONCLUSION

Infertility and its treatments may be involved in increasing the risk of breast and gynecological cancers.

The Association of Kidney Function and Inflammatory Biomarkers with Epithelial Ovarian Cancer Risk

BACKGROUND

One of the mechanisms of ovarian tumorigenesis is through inflammation. Kidney dysfunction is associated with increased inflammation; thus, we assessed its relationship with ovarian cancer risk.

METHODS

In prospectively collected samples, we evaluated the association of kidney function markers and C-reactive protein (CRP) with ovarian cancer risk in the UK Biobank. We used multivariable-adjusted Cox proportional hazards models to evaluate quartiles of serum and urine markers with ovarian cancer risk overall and by histology. We assessed effect modification by CRP (≤3.0, >3.0 mg/L).

RESULTS

Among 232,908 women (1,110 ovarian cancer cases diagnosed from 2006-2020), we observed no association between estimated glomerular filtration rate and ovarian cancer risk (Q4 vs. Q1: HR, 1.00; 95% confidence intervals, 0.83-1.22). Potassium was associated with endometrioid (Q4 vs. Q1: 0.33, 0.11-0.98) and clear cell (4.74, 1.39-16.16) tumors. Poor kidney function was associated with a nonsignificant increase in ovarian cancer risk among women with CRP>3.0 mg/L (e.g., uric acid Q4 vs. Q1; 1.23, 0.81-1.86), but not CRP≤3.0 mg/L (0.83, 0.66-1.05). Other associations did not vary across CRP categories.

CONCLUSIONS

Kidney function was not clearly associated with ovarian cancer risk. Larger studies are needed to evaluate possible histology specific associations. Given the suggestive trend for increased ovarian cancer risk in women with poor kidney function and high CRP, future work is needed, particularly in populations with a high prevalence of inflammatory conditions.

IMPACT

This study provided the first evaluation of markers of kidney function in relation to ovarian cancer risk.

Application of long non-coding RNA RBAT1 in improving diagnosis and prognosis of ovarian carcinoma

Tumorigenesis of bladder cancer and retinoblastoma is correlated with long non-coding RNA (lncRNA) RBAT1. However, the role of RBAT1 in ovarian carcinoma (OC) is unclear. Thus, the study explored the role of RBAT1 in OC. This research enrolled patients with OC ( n  = 68), irritable bowel disease (IBD, n  = 68, females), digestive tract inflammation (DTI, n  = 68, females), urinary tract infection (UTI, n  = 68, females), endometriosis (EM, n  = 68, females), and healthy controls (HCs, n  = 68) to collect plasma sampled. OC and paired non-tumor tissues were collected from patients with OC. RBAT1 accumulation in all samples was analyzed using RT-qPCR. The role of plasma RBAT1 in OC diagnosis was examined using the ROC curves with OC patients as the true positive cases and other patients and HCs as the true negative cases. The role of RBAT1 in predicting the survival of OC patients was analyzed using the survival curve study. RBAT1 was overexpressed in both OC plasma and tissues. Plasma RBAT1 levels were correlated with RBAT1 levels in OC tissues but not in non-tumor tissues. Plasma RBAT1 could distinguish OC patients from other patients and HCs. Patients with high plasma RBAT1 levels had a shorter survival. RBAT1 is overexpressed in OC and might be applied to improve the diagnosis and prognosis of OC.

Endometriosis-Associated Ovarian Cancer: What Are the Implications for Women with Intact Endometrioma Planning for a Future Pregnancy? A Reproductive Clinical Outlook

Endometriosis is a chronic, universal, and prevalent disease estimated to affect up to 1:10 women of reproductive age. Endometriosis-associated ovarian cancer (EAOC) developing at reproductive age is challenging and of concern for women and practitioners alike. This outlook review focuses on the occurrence of EAOC, especially in infertile women or those planning for a future pregnancy, from the perspective of a reproductive endocrinologist, based on recent evidence. Contemporary pathogenesis, genetic profiles, evidence of causality, clinical diagnosis, prognosis, and up-to-date management are discussed. EAOC seems to be merely associated with endometrioma and includes clear-cell and endometrioid ovarian carcinoma. Although endometrioma is frequently found in women of reproductive age (up to 1:18 of women), EAOC appears to be a rare occurrence. These women are of more advanced reproductive age, nulliparous, and hyperestrogenic, with a large-sized unilateral endometrioma (>9 cm) containing solid components and papillary projections. Each case suspected to have EAOC has specific characteristics, and a multidisciplinary discussion and appropriate patient counseling should be conducted to reach an optimal therapeutic plan. Since most of these cases are diagnosed at an early stage with a favorable prognosis, fertility-sparing surgery may be feasible. The pros and cons of fertility preservation techniques should be discussed.

Serum kisspeptin levels in deep-infiltrating, ovarian, and superficial endometriosis: A prospective observational study

The diagnosis of endometriosis may delay for many years due to non-deterministic symptoms and avoiding surgical interventions. Kisspeptins are hormones that interact with endometrial tissue to limit invasions during placentation and various cancers and are suggested to be also associated with endometriosis. This study evaluated if serum kisspeptin levels are associated with the invasion depth in endometriosis. Forty patients between 18 and 45 years of age and admitted to a tertiary-care Obstetrics and Gynecology Department between 2020 and 2021 with a diagnosis of endometriosis, and 40 patients without endometrioma were included in the study. Demographic, obstetric, clinical, and biochemical characteristics were evaluated in patients with superficial (SE) and deep infiltrating (DIE) endometriosis and healthy controls. Twenty patients (50%) had SE, 14 (35%) had DIE, and 22 (55%) had endometrioma in the patient group. Fertility rates were higher among controls, but similar between patients with SE and DIE. CA125 levels were significantly higher in the DIE group. SE and DIE groups had similar kisspeptin values, significantly higher than controls. CA125 and kisspeptin levels were not correlated in study groups. Serum kisspeptin levels were significantly different between endometriosis patients and healthy controls. However, kisspeptin levels were unable to differentiate endometriosis severity. Our results suggest that kisspeptins might play a role in the pathogenesis of endometriosis, which needs further assessment in more comprehensive studies.

Is ovarian cystectomy for atypical ovarian endometrioma safe?: A single center study

Ovarian atypical endometriosis (AE) is a premalignant lesion, and its potential to progress to endometriosis-associated ovarian cancer emphasizes its significance. However, the true risk of malignancy in AE remains unclear. Therefore, this study aimed to investigate the clinical outcomes of ovarian AE after ovarian cystectomy. We retrospectively reviewed the medical records and histopathological reports of 41 patients who had been diagnosed with ovarian AE between January 2011 and April 2020. We reviewed age, obstetric history, age at menarche, preoperative CA 125 level, C-reactive protein level, erythrocyte sedimentation rate, endometriosis stage, mean follow-up duration, postoperative hormonal therapy, and prognosis, including recurrence of endometriosis and malignant transformation. Among 41 patients with pathologically diagnosed ovarian AE, 26 were followed up after cystectomy only. The average follow-up period was 58.27 ± 33.22 months in cystectomy only patients. The mean age of the patients with cystectomy only versus that of patients with endometriosis-associated ovarian carcinoma was 32.73 ± 6.10 versus 48.29 ± 4.35 (P < .01) years. The preoperative CA 125 level was 115.63 ± 219.06 versus 225.75 ± 163.39 (P < .051) U/mL. Patients with endometriosis-associated ovarian carcinoma or other diseases and those who underwent oophorectomy were excluded. After surgery, hormone therapy was administered to 22 of 26 patients, and the remaining 4 patients were followed up without additional treatment. Endometriosis recurrence occurred in 5 patients, 1 of whom underwent second-line laparoscopic ovarian cystectomy. However, no malignant transformations were observed. Ovarian AE has a low possibility of malignant transformation. Conservative treatment is recommended after appropriate ovarian cystectomy, such as enucleation.

A multi-level investigation of the genetic relationship between endometriosis and ovarian cancer histotypes

Endometriosis is associated with increased risk of epithelial ovarian cancers (EOCs). Using data from large endometriosis and EOC genome-wide association meta-analyses, we estimate the genetic correlation and evaluate the causal relationship between genetic liability to endometriosis and EOC histotypes, and identify shared susceptibility loci. We estimate a significant genetic correlation (r_g) between endometriosis and clear cell (r_g = 0.71), endometrioid (r_g = 0.48), and high-grade serous (r_g = 0.19) ovarian cancer, associations supported by Mendelian randomization analyses. Bivariate meta-analysis identified 28 loci associated with both endometriosis and EOC, including 19 with evidence for a shared underlying association signal. Differences in the shared risk suggest different underlying pathways may contribute to the relationship between endometriosis and the different histotypes. Functional annotation using transcriptomic and epigenomic profiles of relevant tissues/cells highlights several target genes. This comprehensive analysis reveals profound genetic overlap between endometriosis and EOC histotypes with valuable genomic targets for understanding the biological mechanisms linking the diseases.

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Endometriosis is genetically correlated with CCOC, ENOC, and HGSOC

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Genetic liability to endometriosis confers risk of these EOC histotypes

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Profound colocalization of genetic associations at endometriosis and EOC risk loci

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Functional annotation highlights shared target genes elucidating the genetic link

Cytogenetic findings of ectopic endometriotic tissue in women with endometriosis and review of the literature

OBJECTIVE

To determine chromosome and gene alterations in ectopic endometrial (EM) tissue which may be implicated in the clinical course or the progression of endometriosis and to review the literature concerning the cytogenetic findings of women with endometriosis.

STUDY DESIGN

15 women who underwent laparoscopic endometriosis surgery at the Athens Genesis Clinic were enrolled in the study. Ectopic endometrial tissue was surgically removed and further analyzed by conventional and molecular cytogenetic techniques. Fluoresent in situ hibridization (FISH) with probes for p53, ATM, MYC, MLL1 and IGH genes, the centromeres of chromosomes 7 and 8 and 7q22/7q31 chromosomal regions was carried out.

RESULTS

Karyotypic analysis revealed no clonal chromosomal abnormalities. However, an increased frequency of polyploidy (55.6%) and sporadic chromosomal abnormalities (40.0%) concerning chromosomes 9, 11, 17 and X were noticed involving mainly deletions, trisomies or monosomies. FISH analysis showed IGH gene rearrangements in 54% of the EM cases and MLL gene rearrangements in 73% of the examined samples. Normal hybridization patterns were observed for p53, ATM and MYC. The increased frequency of polyploidy shown by conventional karyotyping was also confirmed by FISH.

CONCLUSION

Polyploidy, sporadic chromosomal abnormalities, as well as IGH and MLL gene rearrangements, may provoke genetic instability and play a potential role in the development of endometriosis. IGH and MLL gene rearrangements indicate a genetic relation between endometriosis and carcinogenesis. Confirmation of the above gene rearrangements in a large series of women may allow the determination of their possible involvement in the pathogenesis of this complex disease and their possible contribution in the early identification of women in danger for malignant transformation.

Diagnosis and Treatment of Endometriosis. Guideline of the DGGG, SGGG and OEGGG (S2k Level, AWMF Registry Number 015/045, August 2020)

Aims The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society for Gynaecology and Obstetrics (OEGGG) and the Swiss Society for Gynaecology and Obstetrics (SGGG) was to provide consensus-based recommendations for the diagnosis and treatment of endometriosis based on an evaluation of the relevant literature. Methods This S2k guideline represents the structured consensus of a representative panel of experts with different professional backgrounds commissioned by the Guideline Committee of the DGGG, OEGGG and SGGG. Recommendations Recommendations on the epidemiology, aetiology, classification, symptomatology, diagnosis and treatment of endometriosis are given and special situations are discussed.

Ovarian endometriosis, a precursor of ovarian cancer: Histological aspects, gene expression and microRNA alterations (Review)

Ovarian endometriosis is a frequent chronic gynecological disease with an uncertain evolution regarding its progression or association with ovarian malignant lesions. The present review summarized the histological aspects, gene expression and microRNA (miRNA/miR) alterations associated with ovarian endometriosis and cancer and their possible interaction. The endometriosis-ovarian cancer interaction has been proposed by certain researchers as a single entity. Histological results indicated that endometriosis has been in different circumstances coexisting with ovarian cancer, with reference to endometrioid and clear cell carcinoma. Endometriosis with moderate and severe atypia can influence cell proliferation and architecture, resulting in a possible malignant transformation. Gene expression analysis indicated that the pathologies of both endometriosis and ovarian cancer are characterized by genetic instability from a molecular point of view, as several important genetic mutations, including ARID1A, PI3KCA, PTEN, BRCA1, BRCA2, TP53 and KRAS genes, were identified. miRNA alterations have been implicated in the regulation of gene expression. Common dysregulated miRNAs, such as miR-331, miR-335, miR-891, miR-548, miR-124, miR-148, miR-215, miR-192, miR-337, miR-153, miR-155, miR-144, miR-221 and miR-3688 were extensively investigated in understanding endometriosis and ovarian cancer evolution. From a combined viewpoint including histological aspects, gene expression and miRNA alterations, it is reasonable to speculate that endometriosis is associated with ovarian cancer. Ovarian endometriosis lesions may present a risk for ovarian malignant lesions, which supports a model of endometriosis as a malignant precursor. However, the endometriosis-ovarian cancer association is not widely accepted in the literature and additional studies are required to validate this association.

Inhibition of KIF20A by BKS0349 reduces endometriotic lesions in a xenograft mouse model

Several studies have suggested a possible etiological association between ovarian endometriosis and ovarian cancer. Evidence has shown that KIF20A overexpression might confer a malignant phenotype to ovarian tumors by promoting proliferation and inhibiting apoptosis. However, no data about the role of KIF20A in endometriosis have been described. In this study, the human endometrium (n = 4) was transfected by mCherry adenovirus and intraperitoneally implanted in mice. Subsequently, mice were divided in three groups (n = 8/group) that were treated with Vehicle, BKS0349 (KIF20A-antagonist) or cabergoline (dopamine receptor agonist) for 21 days. mCherry-labeled endometriotic lesions were monitored over time using the IVIS Imaging System. Mice were sacrificed 72 h after the last administration; proliferation was evaluated by immunohistochemistry and apoptosis by TUNEL. CCND1 gene expression (G1 phase-related gene) was measured by qRT-PCR. A significant reduction in mCherry-fluorescent signal was observed in the BKS0349 group after treatment ended (D24) compared with D0 (P-value = 0.0313). Moreover, the mCherry signal on D24 showed a significant decrease in the BKS0349 group compared with controls (P-value = 0.0303), along with significant size reduction of endometriotic lesions observed in the BKS0349 group compared with control on D24 (P-value = 0.0006). Functional studies showed a significant reduction in proliferating cells in the BKS0349-treated group compared with controls (P-value = 0.0082). In addition, CCND1 expression was decreased in the BKS0349 group compared with control (P-value = 0.049) at D24 and a significant increase in apoptotic cells among endometriotic lesions in BKS0349-treated mice was observed compared with control (P-value = 0.0317). Based on these findings, we concluded that BKS0349 induces apoptosis and inhibits cell proliferation, reducing endometriotic lesion size and suggesting KIF20A inhibition by BKS0349 as a novel therapeutic treatment for endometriosis.

Incidence of endometrioid and clear-cell ovarian cancer in histological proven endometriosis: the ENOCA population-based cohort study

BACKGROUND

Several studies have suggested that endometriosis is associated with an increased risk of ovarian cancer, especially for the clear-cell and endometrioid subtypes. However, previous studies lack sufficient power or diagnostic certainty.

OBJECTIVE

The objective of the study was to assess the association between histologically proven endometriosis and ovarian cancer in a large population-based cohort study.

STUDY DESIGN

We identified 131,450 women with a histological diagnosis of endometriosis between 1990 and 2015 from the Dutch nationwide registry of histopathology and cytopathology (PALGA). For the control cohort 132,654 women with a benign dermal nevus were matched on age and inclusion year with the endometriosis cases. Histological diagnoses of ovarian, fallopian tubes, and peritoneal cancers between January 1990 and July 2017 were retrieved. Incidence rate ratios were estimated for ovarian cancer and its subtypes for the whole follow-up period as well as for women with more than 1 person-year at risk.

RESULTS

We found a crude incidence rate ratio of 4.79 (95% confidence interval, 4.33-5.31) and an age-adjusted incidence rate ratio of 7.18 (95% confidence interval, 6.17-8.36) for ovarian cancer overall. Endometrioid and clear-cell ovarian cancer had the highest age-adjusted incidence rate ratio of 29.06 (95% confidence interval, 20.66-40.87) and 21.34 (95% confidence interval, 14.01-32.51), respectively. Median age at ovarian cancer diagnosis was 56 years (interquartile range, 49-63) for the endometriosis cohort and 60 years (interquartile range, 53-67) for the nevus cohort, (P < .05). After excluding women with less than 1 person-year at risk following an endometriosis diagnosis, we found a crude incidence rate ratio of 1.04 (95% confidence interval, 0.91-1.19) and an age-adjusted incidence rate ratio of 1.08 (95% confidence interval, 0.87-1.35) for ovarian cancer overall. However, statistically significant age-adjusted incidence rate ratios of 2.29 (95% confidence interval, 1.24-4.20) for clear-cell ovarian cancer and 2.56 (95% confidence interval, 1.47-4.47) for endometrioid ovarian cancer were found.

CONCLUSION

A significantly higher incidence of clear-cell and endometrioid ovarian cancer was found in women with histologically proven endometriosis. Additionally, we found an increased incidence of all ovarian cancer subtypes in histologically proven endometriosis; however, in many of these women, endometriosis and ovarian cancer were diagnosed synchronously after the average menopausal age, which may suggest that the risk of ovarian cancer in endometriosis patients remains, even when clinical endometriosis symptoms are no longer present.

Infertility and ovarian cancer risk: Evidence from nine prospective cohort studies

Epidemiological studies have investigated the relationship between infertility and the risk of ovarian cancer (OC); however, the results have been inconsistent. We therefore conducted the first meta-analysis to update and quantify the aforementioned association based on prospective cohort studies. Studies were identified by searching PubMed, EMBASE and Web of Science databases up to January 8, 2020. We extracted data from the studies and performed quality assessments. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Publication bias, and subgroup, meta-regression and sensitivity analyses were also conducted. Nine prospective cohort studies with a total of 10 383 OC cases and 6 278 830 participants were included in the present study. The summary RR of the association between infertility and the risk of OC was 1.51 (95% CI: 1.35-1.69), with low heterogeneity. Positive associations were observed in most subgroup analyses stratified by predefined factors, including region, duration of follow-up, study quality, causes of infertility, invasiveness of OC, infertility treatment status and adjustment of potential confounding parameters. No significant publication bias was detected. Our findings suggest that infertility in women were associated with an increased risk of OC.

Protein expression pattern of tissue inhibitor of metalloproteinase-3 (TIMP3) in endometriosis and normal endometrium

Given the involvement of different extracellular matrix (ECM) metalloproteinases (MMPs) in endometriosis, the protein expression pattern of tissue inhibitor of metalloproteinase-3 (TIMP3) was analyzed in this study in endometriosis and normal endometrium. Tissue samples were collected prospectively from 64 premenopausal patients undergoing operative laparoscopy. Protein expression of TIMP3 was analyzed immunohistochemically in endometriotic lesions (n = 30) and normal eutopic endometrium from patients with (n = 35) and without (n = 29) endometriosis. Comparison between the three different groups of tissue samples showed that TIMP3 was differentially expressed between the three groups (p = .04). Pair-wise comparisons showed that TIMP3 expression was lower in endometriotic lesions as compared with normal eutopic endometrium from controls (p = .006); the same non-significant trend was found, in the comparison between endometriosis lesions and matched eutopic endometrium. There were no differences in TIMP3 expression in the normal eutopic endometrium between patients with and without endometriosis. In conclusion, TIMP3 seems to be involved in the pathogenesis, pathophysiology, and maintenance of endometriosis and it might be useful as a diagnostic and prognostic marker of endometriosis. Future studies should further investigate this issue, as well as the interplay between TIMPs and different extracellular MMPs in endometriosis.

A Systematic Review and Bioinformatics Study on Genes and micro-RNAs Involving the Transformation of Endometriosis into Ovarian Cancer

BACKGROUND

Along with the description of tumorigenesis processes in endometriosisrelated ovarian cancer, identifying dysregulated miRNAs, the target genes of these miRNAs, and the processes abnormally affected by dysregulated miRNAs is essential, which was our goal.

METHODS

Two reviewers individually evaluated the articles which collected relevant information including genes and miRNAs involved in the transformation of endometriosis into ovarian cancer. To assess the mature sequence of miRNAs and also their chromosomal positions, miRPathDB software was employed. To determine the main target gene predicted for each considered miRNAs, the TargetScanS Web server was applied. The interaction of each gene with other genes associated with endometrial- related ovarian cancer was determined by GeneMANIA software. Finally, to design integrated model of miRNAs-targeted genes interaction network, the Cytoscape software was used.

RESULTS

The final number of studies available for analysis was 6 manuscripts including 22 miRNAs described as involved in the transformation of endometriosis into different subtypes of ovarian cancers (14 miRNAs up-regulated and 8 miRNAs down-regulated). Three miRNAs of miR-141 (upregulated), miR-205 (down-regulated), and miR-125b (down-regulated) were revealed as the originator for genetic interactions leading to carcinogenesis. We could show some common loops and pathways including uncontrolled cell proliferation and abnormal apoptosis (mediated by PTEN gene induced by miR-21 and miR-214), and disaggregation and epithelialization (mediated by ZEB1 and ZEB2 genes induced by miR-200).

CONCLUSION

According to our analysis, up-regulation of miR-141 and down-regulation of miR-205 and miR-125b have a central role in transforming endometriosis to ovarian cancer.

Prognostic importance of atypical endometriosis with architectural hyperplasia versus cytologic atypia in endometriosis-associated ovarian cancer

Objective

Patients with endometriosis are at increased risk of ovarian cancer. It has been suggested that atypical endometriosis is a precursor lesion of endometriosis-associated ovarian cancer (EAOC). The aim of this study is to evaluate if cytologic (cellular) atypia and architectural atypia (hyperplasia), histologic findings described as atypical endometriosis, play a different role in patients with EAOC.

Methods

A prospective study was conducted between January 2014 and April 2017 at our institution with patients undergoing surgery with a histologic diagnosis of endometriosis, ovarian cancer, or EAOC. The prevalence and immunohistologic study (Ki-67, BAF250a, COX-2) of cases of cellular and architectural atypia in endometriosis were analyzed.

Results

Two hundred and sixty-six patients were included: the diagnosis was endometriosis alone in 159 cases, ovarian cancer in 81, and EAOC in 26. Atypical endometriosis was reported in 23 cases (12.43%), 39.13% of them found in patients with EAOC. Endometriosis with cellular atypia was found mainly in patients without neoplasm (71.4%), and endometriosis with architectural atypia was seen in patients with ovarian cancer (88.9%) (p=0.009). Ki-67 was significantly higher in endometriosis patients with architectural atypia than those with cellular atypia.

Conclusion

The diagnosis of endometriosis with architectural atypia is important because it may be a precursor lesion of ovarian cancer; therefore, pathologists finding endometriosis should carefully examine the surgical specimen to identify any patients with hyperplasia-type endometriosis, as they may be at higher risk of developing EAOC.

The risk of breast and gynecological cancer in women with a diagnosis of infertility: a nationwide population-based study

Some studies have suggested that infertility is a risk factor for endometrial, ovarian and breast cancer. The study aimed to create a comprehensive picture of the association between infertility and the risk of ovarian, endometrial and breast cancer, and whether any association could be explained by ovulatory disturbances, endometriosis or nulliparity. In a population-based cohort of 2,882,847 women, cox regression analysis was used to investigate cancer incidence among infertile women. Overall, infertility was associated with a higher incidence rate of ovarian (adjusted hazard ratio [aHR] 1.53, 95% confidence interval [CI] 1.38-1.71) and endometrial cancer (aHR 1.25, 95% CI 1.11-1.40), but not of breast cancer (aHR 0.96, 95% CI 0.92-1.01). Ovarian cancer incidence was higher in women diagnosed with endometriosis, and in nulliparous women with ovulatory disturbances, compared to women with none of the diagnoses. Endometrial cancer incidence was higher in women with ovulatory disturbances, but not in women with endometriosis. These findings suggest that infertility could have long-term consequences of importance to physicians and public health workers.

Evaluation of Circulating Endometrial Cells as a Biomarker for Endometriosis

BACKGROUND

Circulating endometrial cells (CECs) have been reported to be present in the peripheral blood of women with endometriosis (EM), providing clear and specific evidence of the presence of ectopic lesions. In this study, we established a method with a high detection rate of CECs, assessed the diagnostic value of CECs for EM and compared with serum CA125, and proposed a hypothesis for the pathogenesis of EM from the new perspective of CECs.

METHODS

The participants were enrolled prospectively from October 2015 to July 2016. The peripheral blood samples were collected from 59 participants, and the blood cells were isolated for immunofluorescence staining via microfluidic chips. The cells that were positive for vimentin/cytokeratin and estrogen/progesterone receptor and negative for CD45 were identified as CECs. The serum CA125 level was tested with electrochemiluminescence immunoassay.

RESULTS

The detection rate of CECs reached 89.5% (17/19) in the EM group, which was significantly higher than that of the control group (15.0% [6/40], P < 0.001) and was independent of menstrual cycle phases. Furthermore, a positive CEC assay detected 4/5 cases of Stage I-II EM. In contrast, a positive CA125 test had limited value in detecting EM (13/19, 68.4%) and detected only one case of Stage I-II EM.

CONCLUSION

CECs are promising biomarkers for EM with great potential for a noninvasive diagnostic assay.

A review of the risk factors, genetics and treatment of endometriosis in Chinese women: a comparative update

Endometriosis is one of the major causes of economic burden and compromised quality of life in a very large percentage of Asian women. While it is perceived as a benign condition, recent research has shown that it may be a significant cause of infertility and metastatic cancer. It has also been associated with other diseases linked to the functioning of the immune system. Genetic as well as environmental factors are known to affect the manifestation and progression of endometriosis. This review aims to summarize recent research pertaining to the risk factors, diagnosis and treatment of endometriosis in Chinese women. It also provides an overview of identified genetic mutations and polymorphisms and their effects on the risk of developing endometriosis in the Chinese population. A comparison has been drawn between Asian and European-American female populations and the differences in risk factors and treatment responses have been summarized. Since traditional Chinese medicine (TCM) is often used to treat endometriosis, wherever possible, a comparison between efficacies of Western medicine and TCM in the Chinese population has also been provided. Although much progress has been made in the treatment and resolution of endometriosis, several gaps remain and this review also highlights possible areas of future research and advancement that can result in an improvement in patient outcomes and quality of life.

Postprandial increase in serum CA125 as a surrogate biomarker for early diagnosis of ovarian cancer

BACKGROUND

CA125 is a prevalently used serum biomarker for detecting ovarian cancer over the last three decades. However, it has a significant deficiency in screening for early-stage cancer. With the purpose of exploring an effective approach to improve its performance in early diagnosis, we investigated the postprandial fluctuation pattern of cancer-derived CA125 and the underlying mechanism.

METHODS

In two medical centers, 551 patients sonographically diagnosed with ovarian (adnexal) cysts (< 5 cm in diameter) were enrolled and divided into five disease groups (pelvic inflammatory cysts, retention cysts, endometrioma, benign/borderline cystadenoma and malignant cysts). The subtle differences in 1-h postprandial serum CA125 increases were compared between disease groups. A support vector machine (SVM)-based algorithm was used for refining the performance of CA125 postprandial increment. Ovarian cancer xenograft animal and cancer cell models were used to recapitulate the clinical findings and reveal the molecular basis of postprandial blood glucose and insulin in invoking the synthesis/secretion/re-absorption of CA125.

RESULTS

Patients with ovarian cancer presented the highest postprandial increment 13.3 ± 0.7% (mean ± standard deviation) among the five disease groups. Using a CA125 increment ≥ 10% criterion, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) reached 83.3, 96.3, 61.1 and 98.8%, respectively, for early-stage ovarian cancer. This performance was further improved by the SVM-based CA125-increment algorithm, which exhibited 91.7% sensitivity, 99.2% specificity, 89.2% PPV and 99.4% NPV. Both modalities manifested diagnostic advantages over the traditional CA125 test (75.0% sensitivity, 25.4% specificity, 6.6% PPV and 93.6% NPV at the cut-off of 35 U/mL). Regarding the molecular basis, the postprandial blood glucose and insulin-invoked overexpression of Mucin 16 (encoding CA125) were demonstrated in animal and cancer cell models, which were mediated by the PI3K-Akt pathway. Nevertheless, a Mesothelin-based CA125 re-absorption behavior was noted in the treated cancer cells, which contributed to the over-drop following the postprandial peak of serum CA125.

CONCLUSIONS

Cancer-derived serum CA125 possesses a unique and distinctive postprandial pattern, that distinguishes it from the common CA125 elevation in a benign disease condition. The dynamic measurement/assessment strategy can achieve a discriminatory power superior to that of a static test.

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.

Implications of telomeres and telomerase in endometrial pathology

BACKGROUND

Eukaryotic chromosomal ends are linear and are protected by nucleoprotein complexes known as telomeres. The complex structural anatomy and the diverse functions of telomeres as well as the unique reverse transcriptase enzyme, telomerase that maintains telomeres are under intensive scientific scrutiny. Both are involved in many human diseases including cancer, but also in ageing and chronic disease such as diabetes. Their intricate involvement in many cellular processes and pathways is being dynamically deciphered in many organs including the endometrium. This review summarizes our current knowledge on the topic of telomeres and telomerase and their potential role in providing plausible explanations for endometrial aberrations related to common gynaecological pathologies.

OBJECTIVE AND RATIONALE

This review outlines the recent major findings in telomere and telomerase functions in the context of endometrial biology. It highlights the contemporary discoveries in hormonal regulation, normal endometrial regeneration, stem cells and common gynaecological diseases such as endometriosis, infertility, recurrent reproductive failure and endometrial cancer (EC).

SEARCH METHODS

The authors carried out systematic PubMed (Medline) and Ovid searches using the key words: telomerase, telomeres, telomere length, human telomerase reverse transcriptase, telomeric RNA component, with endometrium, hormonal regulation, endometrial stem/progenitor cells, endometrial regeneration, endometriosis, recurrent miscarriage, infertility, endometrial hyperplasia, EC and uterine cancer. Publications used in this review date from 1995 until 31st June 2016.

OUTCOMES

The human endometrium is a unique somatic organ, which displays dynamic telomerase activity (TA) related to the menstrual cycle. Telomerase is implicated in almost all endometrial pathologies and appears to be crucial to endometrial stem cells. In particular, it is vital for normal endometrial regeneration, providing a distinct route to formulate possible curative, non-hormonal therapies to treat chronic endometrial conditions. Furthermore, our current understanding of telomere maintenance in EC is incomplete. Data derived from other malignancies on the role of telomerase in carcinogenesis cannot be extrapolated to EC because unlike in other cancers, TA is already present in proliferating healthy endometrial cells.

WIDER IMPLICATIONS

Since telomerase is pivotal to endometrial regeneration, further studies elucidating the role of telomeres, telomerase, their associated proteins and their regulation in normal endometrial regeneration as well as their role in endometrial pathologies are essential. This approach may allow future development of novel treatment strategies that are not only non-hormonal but also potentially curative.

Transverse Relaxation Rate of Cyst Fluid Can Predict Malignant Transformation of Ovarian Endometriosis

Purpose:

Heme and iron accumulation due to repeated hemorrhage in endometriosis may contribute to a pivotal role in carcinogenesis. We evaluate the clinical application of MR relaxometry in a series of ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC).

Materials and Methods:

A prospective study of diagnostic accuracy was conducted among 82 patients (67 OE and 15 EAOC) to compare MR relaxometry and biochemical measurement of cyst fluid total iron concentration. Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. Phantom experiments were also performed to assess the correlation between the ex vivo R2 values and total iron concentrations.

Results:

Both the results of phantom experiments and in vivo human data confirmed that in vivo R2 values were highly correlated with total iron concentrations. Compared to OE, EAOC exhibit decreased in vivo R2 values and total iron levels, regardless of their age, menopausal status and cyst size. The use of in vivo R2 values retained excellent accuracy in distinguishing EAOC versus OE (sensitivity and specificity: 86% and 94%).

Conclusions:

We have demonstrated that MR relaxometry provides a noninvasive predictive tool to discriminate between EAOC and OE.

Clear cell ovarian cancer and endometriosis: is there a relationship?

Introduction

Ovarian clear cell carcinoma is a rare type of ovarian cancer. In recent years, issues of the common genetic origin of endometriosis and ovarian clear cell carcinoma have been raised.

Aim of this study

Aim of this study was to evaluate the prevalence of this type of cancer, risk factors, prognosis and its potential aetiological association with endometriosis.

Material and methods

In a retrospective study, we analysed histopathological data of patients operated in the First Department of Gynaecology and Obstetrics (MU, Lodz) due to ovarian cancer in 2004-2014. Among the 394 patients operated on for ovarian cancer, clear cell carcinoma was found in 0.02% (9/394). Menstrual history, parity, comorbidities, data from physical examination, operational protocols and histopathological diagnoses were analysed. Follow-up was obtained from 77.8% of patients. Statistical analysis was performed using Microsoft Excel 2013.

Results

The mean age of patients at diagnosis was 57.6 years; the BMI in the study group was 27.2; the majority of patients were multiparous (77.8%). Clear cell carcinoma was detected mostly at stage Ia (n = 4). The concentration of Ca125 in the study group had an average of 142.75 U/ml and a median of 69.3 U/ml. The coexistence of endometriosis could not be clinically or histologically confirmed amongst our patients. The most common comorbidity in the study group was hypertension.

Conclusions

In our clinical material, ovarian clear cell carcinoma is a rare histopathological specimen with a prognostic value comparable to that of serous ovarian cancer. Due to the rarity of this histopathological subtype, proving a cause-and-effect relationship between it and endometriosis can only be elucidated through statistical studies of the entire population.

Immunohistochemical expression pattern of metastasis suppressors KAI1 and KISS1 in endometriosis and normal endometrium

OBJECTIVE

To analyze the expression pattern of metastasis suppressors KAI1 and KISS1 in the endometrium of patients with and without endometriosis.

STUDY DESIGN

In this pilot study, tissue samples were prospectively collected from 38 patients with endometriosis and 29 without endometriosis, undergoing operative laparoscopy in the proliferative phase of the menstrual cycle; diagnosis or absence of endometriosis was confirmed histologically. Protein expression of KAI1 and KISS1 were analyzed immunohistochemically in endometriotic lesions and the eutopic endometrium of patients with endometriosis and without endometriosis.

RESULTS

KAI1 expression was significantly decreased in the glandular eutopic endometrium of endometriosis patients as compared with that of patients without endometriosis (p=0.008). On the other hand, in endometriosis patients, KAI1 expression was significantly increased in the ectopic as compared with the eutopic endometrial stroma (p=0.021). There were no other significant differences in KAI1 expression between different groups. KISS1 expression in the ectopic glandular endometrium was significantly increased as compared with the eutopic glandular endometrium from patients with (p=0.004) and without endometriosis (p=0.008). There was no significant difference in KISS1 protein expression in the stromal endometrium between the three groups.

CONCLUSIONS

KAI1 and KISS1 are implicated in the pathogenesis and maintenance of endometriosis. Future studies should investigate whether KAI1 and KISS1 could be used as markers for early and minimally invasive detection of endometriosis based on their differential protein expression pattern in the eutopic endometrium of patients with and without endometriosis.

Oridonin effectively reverses cisplatin drug resistance in human ovarian cancer cells via induction of cell apoptosis and inhibition of matrix metalloproteinase expression

Cisplatin is a first generation platinum‑based chemotherapeutic agent, however, the extensive application of cisplatin inevitably results in drug resistance, which is a major obstacle in cancer chemotherapy. The aim of the present study was to investigate the efficiency of reversing cisplatin‑resistance with the use of combination therapy with oridonin and cisplatin in human ovarian cancer cells, and attempt to reduce the side effects of the therapeutic agents when used alone. The half maximal inhibitory concentration (IC50) values of cisplatin were determined in cisplatin‑sensitive and cisplatin‑resistant ovarian cancer cells using an MTT assay. IC50 values of cisplatin in A2780, A2780/DDP, SKOV3 and SKOV3/DDP cells were significantly decreased in a time‑dependent manner. The antitumor effect of oridonin in A2780/DDP cells was also detected by the MTT assay and the inhibitory effects of oridonin increased in a dose‑ and time‑dependent manner. A2780/DDP cells were treated with 20 µM oridonin in combination with increasing concentrations of cisplatin for 48 h, and the result demonstrated that oridonin synergistically increased the antitumor effects of cisplatin in A2780/DDP cells. Notably, the combination treatment of oridonin and cisplatin effectively reversed cisplatin resistance and the IC50 values were significantly decreased from 50.97 µM and 135.20 to 26.12 µM and 73.00 µM in A2780/DDP and SKOV3/DDP cells at 48 h, respectively. Furthermore, oridonin induced cell apoptosis in a dose‑dependent manner and promoted cell‑cycle arrest at the G0/G1 phase in ovarian cancer cells. Oridonin and cisplatin synergistically increased the cell apoptosis rate of A2780/DDP cells, which was detected by fluorescence‑activated cell sorting analysis. Downregulated expression levels of Bcl‑2 and upregulated the expression of Bax protein were demonstrated by western blot analysis, further indicating increased apoptosis. In addition, the expression levels of matrix metalloproteinase (MMP)‑2 and MMP‑9 decreased in a dose‑dependent manner with oridonin treatment. The results from the present study demonstrated that oridonin exerted a synergistic effect with cisplatin to inhibit proliferation and induce cell apoptosis in cisplatin‑resistant ovarian cancer cells. Thus, combination therapy with oridonin and cisplatin effectively reversed cisplatin resistance in human ovarian cancer cells, which may have useful clinical applications.

The Risk of Epithelial Ovarian Cancer of Women With Endometriosis May be Varied Greatly if Diagnostic Criteria Are Different: A Nationwide Population-Based Cohort Study

This article aims to test the hypothesis that the risk of epithelial ovarian cancer (EOC) in women with endometriosis might be changed by enrolling different population. A nationwide 14-year historic cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan and the Registry for Catastrophic Illness Patients was conducted. A total of 239,385 women aged between 20 and 51 years, with at least 1 gynecologic visit after 2000, were analyzed. Cases included women with a diagnosed endometriosis, which was established along a spectrum from at least 1 medical record of endometriosis (recalled endometriosis) to tissue-proved ovarian endometriosis (n = X). Controls included women without any diagnosis of endometriosis (n = 239,385 - X). We used Cox regression, and computed hazard ratios (HRs) with 95% confidence intervals (95% CI) to determine the risk of EOC in patients. The EOC incidence rates (IRs, per 10,000 person-years) of women with endometriosis ranged from 1.90 in women with recalled endometriosis to 18.70 in women with tissue-proved ovarian endometrioma, compared with those women without any diagnosis of endometriosis (0.77-0.89), contributing to crude HRs ranging from 2.59 (95% CI, 2.09-3.21; P < 0.001) to 24.04 (95% CI, 17.48-33.05; P < 0.001). After adjustment for pelvic inflammatory disease, infertility, Charlson co-morbidity index, and age, adjusted HRs were ranged from the lowest of 1.90 (95% CI, 1.51-2.37; P < 0.001) in recalled endometriosis to the highest of 18.57 (95% CI, 13.37-25.79; P < 0.001) in tissue-proved ovarian endometrioma, which was inversely related to the prevalence rate of endometriosis (from the highest of 30.80% in recalled endometriosis to the lowest of 1.54% in tissue-proved ovarian endometrioma). The risk of EOC in women with endometriosis varied greatly by different criteria used. Women with endometriosis might have a more apparently higher risk than those reported by systematic review and meta-analysis.