Endometriosis Subtypes May Identify Ovarian Cancer Risk

TOPLINE: 

Women with endometriosis show a higher risk for ovarian cancer, and the magnitude varies with the subtype of endometriosis, with the highest risk seen in those with deep infiltrating endometriosis alone or with concurrent ovarian endometriomas.

METHODOLOGY:

• Women with endometriosis have almost double the risk of developing ovarian cancer compared with those without the condition. Understanding how different subtypes of endometriosis relate to various types of ovarian cancer could help guide clinical decisions for these patients.
• Researchers evaluated 78,476 women with endometriosis (mean age at diagnosis, 36 years) and 372,430 matched women without endometriosis from the Utah Population Database between 1992 and 2019.
• The mean follow-up duration was 12 years.
• Most women were parous (75%), and 6% had bilateral oophorectomy during the follow-up period.

TAKEAWAY: 

• Overall, 597 patients were diagnosed with ovarian cancer; cases were grouped into type I (endometrioid, clear cell, mucinous, and low-grade serous) and type II (high-grade serous).
• Women with endometriosis showed a 4.2 times higher risk for all ovarian cancer histotypes compared with women without endometriosis (95% CI, 3.59-4.91); the adjusted hazard ratios (aHRs) ranged from 2.70 for high-grade serous and 11.15 for clear cell carcinoma.
• The strongest associations were seen in women with deep infiltrating endometriosis alone or with concurrent ovarian endometriomas, who had an approximately 10-fold higher overall risk for ovarian cancer (aHR, 9.66) and 19 times higher risk for type I disease (aHR, 18.96).
• For every 10,000 women with endometriosis, there were 9.90 additional cases of ovarian cancer over a 12-year period compared with women without endometriosis.

IN PRACTICE: 

“By quantifying the strong associations between deep infiltrating endometriosis and/or ovarian endometriomas subtypes and ovarian cancer risk, this study identified a population that may benefit from ovarian cancer screening or more aggressive prevention strategies, ” the authors wrote. “Study observations of how endometriosis subtypes are differentially associated with risk of ovarian cancer could lead to novel hypotheses regarding ovarian cancer etiology,” they added. 

SOURCE:

The study was led by Mollie E. Barnard, ScD, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, and was published online on July 17, 2024, in JAMA. 

LIMITATIONS:

There could be misclassification of endometriosis subtypes and ovarian cancer histotypes. The study did not include data on oral contraceptive use, which may have influenced the observed associations. The findings may not be generalizable to populations outside of Utah. 

DISCLOSURES: 

This research was supported by the National Cancer Institute, National Center for Research Resources, Utah Department of Health and Human Services, the University of Utah, and other sources. Several authors reported receiving grants outside this work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.