Endometriosis-Associated Ovarian Cancer: From Molecular Pathologies to Clinical Relevance

Endometriosis is a chronic condition affecting reproductive-aged women, characterized by the growth of ectopic endometrial tissue. Despite being benign, endometriosis is associated with an increased risk of certain cancers, including endometriosis-associated ovarian cancer (EAOC). Ovarian cancer is rare, but more common in women with endometriosis, particularly endometrioid and clear-cell carcinomas. Factors such as hormonal imbalance, reproductive history, environmental exposures, and genetic predisposition contribute to the malignant transformation of endometriosis. Thus, understanding potential risk factors causing malignancy is crucial. Over the past few decades, various genetic mutations, microRNAs, as well as tumor microenvironmental factors have been identified, impacting pathways like PI3K/AKT/mTOR, DNA repair mechanisms, oxidative stress, and inflammation. Thus, this review aims to summarize molecular studies involved in EAOC pathogenesis as potential therapeutic targets. However, further research is needed to better understand the molecular and environmental factors driving EAOC development, to target the susceptibility of endometriotic lesions to malignant progression, and to identify effective therapeutic strategies.

New insights about endometriosis-associated ovarian cancer: pathogenesis, risk factors, prediction and diagnosis and treatment

Previous studies have shown that the risk of malignant transformation of endometriosis in premenopausal women is approximately 1%, significantly impacting the overall well-being and quality of life of affected women. Presently, the diagnostic gold standard for endometriosis-associated ovarian cancer (EAOC) continues to be invasive laparoscopy followed by histological examination. However, the application of this technique is limited due to its high cost, highlighting the importance of identifying a non-invasive diagnostic approach. Therefore, there is a critical need to explore non-invasive diagnostic methods to improve diagnostic precision and optimize clinical outcomes for patients. This review presents a comprehensive survey of the current progress in comprehending the pathogenesis of malignant transformation in endometriosis. Furthermore, it examines the most recent research discoveries concerning the diagnosis of EAOC and emphasizes potential targets for therapeutic intervention. The ultimate objective is to improve prevention, early detection, precise diagnosis, and treatment approaches, thereby optimizing the clinical outcomes for patients.

Immunochemical analysis of iron transporters and M2 macrophages in ovarian endometrioma and clear cell adenocarcinoma

The association between iron ions and endometriosis-associated ovarian cancer (EAOC) has been previously investigated to elucidate EAOC carcinogenesis; however, the dynamics of iron deposition in the endometrial epithelium and endometrial stroma of ovarian endometrioma (OE) remains unknown. The present study aimed to determine the expression of iron transporters on the cell surface and the distribution of tumor-associated macrophages (TAMs) englobed with iron in the endometrial stroma. The current retrospective study investigated 20 OE and 18 ovarian clear cell adenocarcinoma (CCC) samples, using Perls Prussian blue staining and immunohistochemistry of iron transporters, including divalent metal transporter 1 (DMT1), transferrin receptor (TfR) and ferroportin (FPN). Additionally, samples were stained for CD68, CD11c, CD163 and CD206, and double-immunostained for iron and CD163 to define the distribution of macrophages. Iron transporters were identified on the endometrial epithelium of OE and CCC tumor cells, and TAMs were englobed with iron in the endometrial stroma of OE and CCC. Histological findings revealed DMT1 upregulation in OE and CCC, whereas lower TfR and FPN expression was observed in OE than in CCC. M2 macrophages were englobed with iron ions in the deep layers of the OE and CCC stroma. The endometrial epithelium located in the endometrial stroma of one patient with OE and the endometrial epithelium adjacent to CCC in two patients with CCC stained positive for the tumor proliferation marker Ki67. Epithelium infiltrating the stroma of OE may become the origin of cancer under the influence of M2 macrophages englobed with iron. These findings provide new perspectives on the malignant transformation of OE into EAOC and its possibility as a precancerous index.

Histopathology and ARID1A Expression in Endometriosis- Associated Ovarian Carcinoma (EAOC) Carcinogenesis Model with Endometrial Autoimplantation and DMBA Induction

BACKGROUND

Ovarian carcinoma is one of the most deadly malignancies in the gynecologic field. The cause is not yet known, and the clinical symptoms are not specific. Endometrioid carcinoma and ovarian clear cell carcinoma can originate from endometriosis and are known as endometriosis-related ovarian carcinoma (EAOC). Development of EAOC experimental animal models is needed for basic research and clinical preparation of human tissue tests. This study aimed to determine the role of the ARID1A gene mutation in the carcinogenetic process of EAOC in experimental animal models induced with DMBA.

METHODS

In this study, the EAOC experimental model was developed using the autoimplantation technique and DMBA induction. This study involved placebo surgery mice (sham), endometrial autoimplantation, and a combination of endometrial autoimplantation and DMBA induction, which were sacrificed at weeks 5, 10, and 20, respectively. Histopathological assessment and immunohistochemical ARID1A staining with an assessment of positive percentages were carried out on 200 cells.

RESULTS

This study produced 1 (20%) atypical endometriosis and 1 (20%) clear cell carcinoma at implantation and after 10 weeks of DMBA induction, and 100% endometrioid carcinoma in the DMBA-induced group. ARID1A staining did not show any significant difference (p = 0.313) in all groups.

CONCLUSION

The combination of endometrial autoimplantation techniques and DMBA induction in the ovary produced atypical endometriosis, clear cell carcinoma, and endometrioid carcinoma, where time is an important factor. There was no significant difference in ARID1A expression between the treatment and control groups.

MiR-191 inhibits TNF-α induced apoptosis of ovarian endometriosis and endometrioid carcinoma cells by targeting DAPK1

Emerging evidence showed that miRNA dysregulation is involved in the development of endometriosis and may contribute to pathological process of endometriosis associated ovarian cancer (EAOC). miR-191 is one of the most differentially expressed miRNAs in pairwise comparisons among healthy controls, endometriosis, and EAOC patients. However, its regulative network in endometriosis and EAOC are still not clear. This study explored the role of miR-191 in TNF-α induced cell death in ovarian endometriosis and endometrioid carcinoma cells. Based on tissues samples collected from healthy controls, endometriosis, and EAOC patients, this study verified significantly higher expression of miR-191 in endometriosis and endometrioid cancer. Interestingly, we also observed inverse expression trend between miR-191 and DAPK1, a positive mediator of programmed cell death. By conducting luciferase assay, we confirmed miR-191 can directly target DAPK1 and regulate its expression. Functionally, we also found DAPK1 can promote TNF-α induced cell death. DAPK1 knockdown in endometriosis CRL-7566 cells can weaken its response to TNF-α induced cell death, while its overexpression in endometrioid cancer cells CRL-11731 enhanced the response. These functions of DAPK1 can be directly modulated by miR-191. Therefore, the miR-191-DAPK1 axis may play an important role modulating the response of ovarian endometriosis and endometrioid carcinoma cells to death-inducers and might contribute malignant transformation of endometriosis.