Endometriosis and malignancy: The intriguing relationship

A cause-effect relationship between uterine diseases and breast cancer: A bidirectional Mendelian randomization study

Objective

To explore the cause-effect relationship between uterine diseases (UDs) and breast cancer (BC) and underlying mechanism of the cause-effect relationship, enhance understanding of the association between BC and UDs.

Methods

A two-sample bidirectional Mendelian randomization (MR) analysis was conducted. We obtained summary statistics data from GWAS for BC, endometriosis, endometrial cancer (EC), uterine leiomyoma (UL), uterine polyps (UP), and cervical cancer (CC). Independent SNPs were selected as instrumental variables (IVs) for each disease. The inverse variance weighted (IVW) method was primary used for estimating the causal association between UDs and BC. To further evaluate the consistency and dependability of the results, we also utilized the weighted median, weighted mode, simple mode, and MR-Egger methods, along with sensitivity analyses. Furthermore, a supplementary analysis focusing on the variants linked to BC and UDs was conducted. This involved identifying corresponding genes and subsequently performing KEGG/GO analyses to investigate potential molecular mechanisms.

Results

The results indicated significant associations between genetic susceptibility to endometriosis, EC, and UL with BC risk. The odds ratios (ORs) were as follows: endometriosis at 0.963 (95 % CI, 0.942-0.984; p = 7.11e-5), EC at 1.056 (95 % CI, 1.033-1.081; p = 2.39e-6), and UL at 1.027 (95 % CI, 1.006-1.048; p = 0.010). Conversely, the predisposition to BC inferred from genetic factors was markedly correlated with an elevated risk of EC indicated by an OR of 1.066 (95 % CI, 1.019-1.116; p = 0.006), and was correlated with UP risk (OR, 1.001,95 % CI, 1.000-1.002; p = 0.001).Sensitivity analyses provided weak evidence for these effects, suggesting that the study's outcomes are consistent and trustworthy. Further analysis of the genetic variants associated with BC, and these related genes are enriched in Cellular senescence, GnRH secretion, Phosphatidylinositol signaling system, and so on.

Conclusion

This study corroborates the existence of a reciprocal causal relationship between BC and EC, as well as highlighting the substantial correlations between a genetic susceptibility to UL and endometriosis with BC. BC may exert their influence on EC and UP through Cellular senescence, GnRH secretion, and other pathways. These discoveries offer fresh perspectives on the genetic pathogenesis of BC and UDs, and can guide future experimental studies. Additionally, they lay down a groundwork for the development of tailored preventative and therapeutic strategies moving forward.

Breast Cancer in Patients with Previous Endometriosis Showed Low Aggressive Subtype

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

Pictorial essay: MRI evaluation of endometriosis-associated neoplasms

Endometriosis is a frequent pathology mostly affecting women of young age. When typical aspects are present, the diagnosis can easily be made at imaging, especially at MRI. Transformation of benign endometriosis to endometriosis-associated neoplasms is rare. The physiopathology is complex and remains controversial. Endometrioid carcinoma and clear cell carcinoma are the main histological subtypes. Our goal was to review the main imaging characteristics that should point to an ovarian or extra-ovarian endometriosis-related tumor, especially at MRI, as it may be relevant prior to surgical management.Key points• Transformation of benign endometriosis to endometriosis-associated neoplasms is rare.• MRI is useful when displaying endometriosis lesions associated to an ovarian tumor.• Subtraction imaging should be used in the evaluation of complex endometriomas.

The role of iron in the pathogenesis of endometriosis: a systematic review

STUDY QUESTION

What is the role of iron in the pathophysiology of endometriosis?

SUMMARY ANSWER

Iron excess is demonstrated wherever endometriotic tissues are found and is associated with oxidative stress, an inflammatory micro-environment, and cell damage; the iron-mediated oxidative stress is independently linked to subfertility, symptom severity, and malignant transformation.

WHAT IS KNOWN ALREADY

Iron is found in excess in endometriotic tissues, and multiple mechanisms have been studied and posited to explain this. It is clear that iron excess plays a vital role in promoting oxidative stress and cell damage. The evidence base is large, but no comprehensive reviews exist to summarize our understanding and highlight the overarching themes to further our understanding and suggest future directions of study for the field.

STUDY DESIGN SIZE DURATION

This systematic review with a thematic analysis retrieved studies from the PubMed, Embase, Web of Science, and Cochrane Library databases and searches were conducted from inception through to August 2022. Human and animal studies published in the English language were included and identified using a combination of exploded MeSH terms ('Iron' and 'Endometriosis') and free-text search terms ('Iron', 'Ferric', 'Ferrous', 'Endometriosis', 'Endometrioma').

PARTICIPANTS/MATERIALS SETTING METHODS

This review was reported in accordance with the PRISMA guidelines. All studies reporting original data concerning the role of iron or iron complexes in the pathophysiology of endometriosis were included. Studies that did not report original data or provided a review of the field were excluded. Bias analysis was completed for each included study by using the Newcastle-Ottawa scoring system.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 776 records identified and these were screened down to 53 studies which met the eligibility criteria, including 6 animal and 47 human studies, with 3556 individual participants. Iron excess is demonstrated in various tissues and fluids, including ovarian endometriomas, ovarian follicles, ectopic endometriotic lesions, and peritoneal fluid. Markers of oxidative stress are strongly associated with high iron levels, and aberrant expression of iron-transport proteins has been demonstrated. Abnormal resistance to ferroptosis is likely. Iron-mediated oxidative stress is responsible for a pro-inflammatory micro-environment and is linked to subfertility, symptom severity, and, possibly, malignant transformation.

LIMITATIONS REASONS FOR CAUTION

A minority of the included studies were of objectively low quality with a high risk of bias and may lead to misleading conclusions. Additionally, multiple studies failed to appropriately characterize the included patients by known confounding variables, such as menstrual cycle phase, which may introduce bias to the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Current literature depicts a central role of aberrant iron mechanics and subsequent oxidative stress in endometriosis. It is likely that iron excess is at least partly responsible for the persistence and proliferation of ectopic endometriotic lesions. As such, iron mechanics represent an attractive target for novel therapeutics, including iron chelators or effectors of the iron-oxidative stress pathway. There are significant gaps in our current understanding, and this review highlights and recommends several topics for further research. These include the role of iron chelation, resistance to ferroptosis, the relationship between iron excess and localized hypoxia, systemic iron pathophysiology in endometriosis, and the role of oxidative stress in malignant transformation.

STUDY FUNDING/COMPETING INTERESTS

J.W. and S.G.P. are supported by clinical fellowships at Liverpool University Hospital NHS Foundation trust. No additional funding was requested or required for the completion of this work. C.J.H. is supported by a Wellbeing of Women project grant (RG2137). D.K.H. is supported by a Wellbeing of Women project grant (RG2137) and an MRC clinical research training fellowship (MR/V007238/1). The authors have no conflicts of interest to declare.

REGISTRATION NUMBER

A protocol was prospectively registered with the PROSPERO database in August 2021 (CRD42021272818).

Endometriosis-associated endometrioid adenocarcinoma of the fallopian tube synchronized with endometrial adenocarcinoma: A case report

BACKGROUND

Endometriosis is a common gynecological disorder that affects women of reproductive age. It is characterized by a cancer-like invasion of the extra-uterine endometrium and exhibits a strong association with ovarian clear cell cancer and endometrioid cancer. Endometriosis-associated fallopian tube endometrioid adenocarcinoma synchronized with endometrial adenocarcinoma was rarely reported.

CASE SUMMARY

A 49-year-old woman was referred to our hospital complaining about abnormal vaginal bleeding for three years following unsatisfactory medication. Intraoperative frozen sections unexpectedly unveiled an endometrioid cancer of the left fallopian tube with superficial invasion surrounded by diffuse endometriosis synchronized with endometrioid endometrial cancer.

CONCLUSION

It was difficult to make a differential diagnosis when confronted with incidental findings of fallopian tube cancer lesions synchronized with endometrial cancer. The key differential diagnosis of primary endometriosis-associated endometrioid adenocarcinoma of the fallopian tube from endometrial adenocarcinoma involvement relies on the pathological identification of malignant transformation in fallopian tube endometriosis disease.

Oxidized LDL promotes EMS-induced angiogenesis by increasing VEGF-A expression and secretion by endometrial cells

BACKGROUND

Endometriosis (EMS) is a "tumour-like" gynaecological disease with distant metastasis, and studies have shown that EMS can induce distant metastasis through vascular vessels, but the driving factors and their mechanism are not clear.

METHODS

We used an EMS animal model and gene knockout technique to explore the role of EMS-induced angiogenesis in EMS metastasis in vivo and in vitro and clarify the role and molecular mechanism of oxLDL in promoting EMS-induced angiogenesis.

RESULTS

We found that microvascular density (MVD) in metastasized ectopic endometrium and eutopic endometrial tissue was higher than that in normal endometrial tissue, and plasma oxLDL was positively correlated with the distant metastasis of EMS. Furthermore, we clarified that oxLDL enhanced the MVD of endometrial tissue by increasing VEGF-A expression and secretion in endometrial cells. Finally, we illustrated the mechanism by which oxLDL promotes VEGF-A expression through the AKT-HIF-1α signalling pathway.

CONCLUSION

OxLDL is a risk factor promoting distant EMS metastasis by increasing VEGF-A expression and secretion through AKT-HIF-1α signalling. This finding may provide theoretical support and therapeutic targets for the clinical prevention and treatment of EMS.

The application of risk models based on machine learning to predict endometriosis-associated ovarian cancer in patients with endometriosis

INTRODUCTION

There is currently no satisfactory model for predicting malignant transformation of endometriosis. The aim of this study was to construct and evaluate a risk model incorporating noninvasive clinical parameters to predict endometriosis-associated ovarian cancer (EAOC) in patients with endometriosis.

MATERIAL AND METHODS

We enrolled 6809 patients with endometriosis confirmed by pathology, and randomly allocated them to training (n = 4766) and testing cohorts (n = 2043). The proportion of patients with EAOC in each cohort was similar. We extracted a total of 94 demographic and clinicopathologic features from the medical records using natural language processing. We used a machine learning method - gradient-boosting decision tree - to construct a predictive model for EAOC and to evaluate the accuracy of the model. We also constructed a multivariate logistic regression model inclusive of the EAOC-associated risk factors using a back stepwise procedure. Then we compared the performance of the two risk-predicting models using DeLong's test.

RESULTS

The occurrence of EAOC was 1.84% in this study. The logistic regression model comprised 10 selected features and demonstrated good discrimination in the testing cohort, with an area under the curve (AUC) of 0.891 (95% confidence interval [CI] 0.821-0.960), sensitivity of 88.9%, and specificity of 76.7%. The risk model based on machine learning had an AUC of 0.942 (95% CI 0.914-0.969), sensitivity of 86.8%, and specificity of 86.7%. The machine learning-based risk model performed better than the logistic regression model in DeLong's test (p = 0.036). Furthermore, in a prospective dataset, the machine learning-based risk model had an AUC of 0.8758, a sensitivity of 94.4%, and a specificity of 73.8%.

CONCLUSIONS

The machine learning-based risk model was constructed to predict EAOC and had high sensitivity and specificity. This model could be of considerable use in helping reduce medical costs and designing follow-up schedules.

Endometriosis and Infertility: A Long-Life Approach to Preserve Reproductive Integrity

Laparoscopic surgery was originally considered the gold standard in the treatment of endometriosis-related infertility. Assisted reproductive technology (ART) was indicated as second-line treatment or in the case of male factor. The combined approach of surgery followed by ART proved to offer higher chances of pregnancy in infertile women with endometriosis. However, it was highlighted how pelvic surgery for endometriosis, especially in cases of ovarian endometriomas, could cause iatrogenic damage due to ovarian reserve loss, adhesion formation (scarring), and ischemic damage. Furthermore, in the last few years, the trend to delay the first childbirth, recent technological advances in ultrasound diagnosis, and technological progress in clinical and laboratory aspects of ART have certainly influenced the approach to infertility and endometriosis with, ART assuming a more relevant role. Management of endometriosis should take into account that the disease is chronic and involves the reproductive system. Consequently, treatment and counselling should aim to preserve the chances of pregnancy for the patient, even if it is not associated with infertility. This review will analyse the evolution of the management of infertility associated with endometriosis and propose an algorithm for treatment decision-making based on the most recent acquisitions.

Genetic Contribution of Endometriosis to the Risk of Developing Hormone-Related Cancers

Endometriosis is a common gynecological disorder that has been associated with endometrial, breast and epithelial ovarian cancers in epidemiological studies. Since complex diseases are a result of multiple environmental and genetic factors, we hypothesized that the biological mechanism underlying their comorbidity might be explained, at least in part, by shared genetics. To assess their potential genetic relationship, we performed a two-sample mendelian randomization (2SMR) analysis on results from public genome-wide association studies (GWAS). This analysis confirmed previously reported genetic pleiotropy between endometriosis and endometrial cancer. We present robust evidence supporting a causal genetic association between endometriosis and ovarian cancer, particularly with the clear cell and endometrioid subtypes. Our study also identified genetic variants that could explain those associations, opening the door to further functional experiments. Overall, this work demonstrates the value of genomic analyses to support epidemiological data, and to identify targets of relevance in multiple disorders.