Rare but Still There: A Scoping Review on Endometriosis-Associated Ovarian Cancer

Endometriosis is a medical condition affecting at least up to 10% of women of reproductive age. This condition occurs when ectopic endometrial glands and stroma implant outside the uterus and there are several theories regarding the underlying origins of the disease. Endometriosis is one of the major causes of severe dysmenorrhoea, chronic pelvic pain and infertility. While endometriosis is generally a non-malignant condition, it rarely may transform into an invasive cancer, and increase the risk for epithelial ovarian cancer, notably endometrioid or clear cell ovarian cancer. Despite the increased risk, the mechanisms behind the development of endometriosis-associated ovarian cancer (EAOC) are not yet well understood. Recent investigations have delved into the intricate interplay between endometriosis and EAOC, exploring pathways involving oxidative stress, inflammation, hyperestrogenism, and the discovery of genetic mutations within endometriotic lesions that hint at a transition towards invasive carcinoma. Efforts have been made to identify intermediary lesions between endometriosis and EAOC, which may enable earlier detection of endometriosis at risk of malignant transformation or even prevention of the transformation altogether. However, given the rarity of this malignancy, there is still the risk of late or missed diagnosis, with the risk of inappropriate management being offered to the patient, and the higher risk of poor prognosis and increased morbidity and mortality. This scoping review aims to summarize existing data on EAOC, with a focus on endometrioid and clear cell histologic subtypes. It also provides insights into its identification, prognosis, and delineating management strategies, seeking to provide a holistic understanding of the complexities surrounding EAOC, facilitating further research and the development of more effective prevention and treatment approaches.