Endometriosis Progression to Ovarian Cancer

Although it is a rare complication, patients with endometriosis may progress to ovarian cancer. As health care practitioners‘ understanding about endometriosis grows, so does knowledge about the relationship between endometriosis and ovarian cancer.

In a recent study, researchers sought to examine patient populations at risk for endometriosis-associated ovarian cancer and to identify predictive risk factors for this progression. Lead study author Jàn Varga, PhD, from Šafárik University and L. Pasteur University Hospital (Košice, Slovakia), discusses the study findings and the implications for clinical practice.

Consultant360: Can you begin by providing some background on the impetus for the study and its relationship to prior or similar studies?

Dr Varga: Endometriosis is predominantly known as a disease causing pain and infertility. Less attention is paid to its potential for malignant overgrowth. Although the incidence of malignant transformation is low, certain groups of patients may develop ovarian cancer, called endometriosis-associated ovarian cancers. Mainly endometrioid ovarian cancers and clear cell ovarian cancers are assigned here. Predictive factors of endometriosis progression into ovarian cancer are not known yet. This was the main motivation to construct the study.

C360: Of the endometriosis patients in your study, 20% had atypical endometriosis. What patient populations with endometriosis are most at risk of progression to ovarian cancer?

Dr Varga: Although the incidence of malignant overthrow is low, accounting for less than 1%, we need to be careful with the patients containing an atypia in their histology. In the clinical aspect, the patients with long-term history of endometriosis, advanced stage of disease, as well as the patients with big endometriomas should be under more precise observation. Deep infiltrating endometriosis does not point to a significant risk of malignant transformation. The reason is most probably the absence of ovarian microenvironment.  

C360: How does the presence of endometriosis in individuals with ovarian cancer impact their care journey?

Dr Varga: Endometriosis-associated ovarian cancers are more common in individuals with endometriosis in their histology. Thus, not every endometriosis-associated ovarian cancer contains endometriosis in its structure. Endometrioid ovarian cancers are usually less aggressive, with slow progression, which often leads to detection of histologic transition from precursor to invasive carcinoma. There is no difference in the management of ovarian cancer patients with or without endometriosis. The presence of this precursor in endometriosis patients gives us wider possibilities of early stage cancer detection.   

C360: What are the implications of your study results for clinical practice?

Dr Varga: The incidence of endometriosis as well as the peculiarities connected with the management of these patients are the main reasons why endometriosis patients should be centralized. Pathological assessment of the tissue containing an endometriosis should include the criteria for atypical endometriosis as were defined. All patients with atypical endometriosis should be more precisely observed. Patients with benign endometriosis but with long persistent disease, as well as advanced stage patients and large size endometriomas, also represent high-risk patients. Prevention protocol, including bilateral salpingo-oophorectomy should be considered to prevent ovarian cancer development, although more studies are needed.

C360: What else should our audience of gynecologists and other health care providers know about the relationship between endometriosis and ovarian cancer?

Dr Varga: In recent years, endometriosis has undergone a noteworthy renaissance in the recognition of its potential. We have to focus on the high-risk patients and try to define preventive surgical protocols for these patients. There is still an absence of sufficient detection in early stages of ovarian cancers. Generally, the disease etiopathogenesis is well elucidated, which allows us to construct preventive pathological and surgical protocols.

Reference:

Varga J, Reviczká A, Háková H, Švajdler P,  Rabajdová M, Ostró A. Predictive factors of endometriosis progression into ovarian cancer. J Ovarian Res. 2022;15(1):5. doi:10.1186/s13048-021-00940-8