Women with ovarian endometriomas or deep infiltrating endometriosis are at a significantly increased risk of ovarian cancer, according to a recent study published in JAMA.1
Takeaways
- Women with ovarian endometriomas or deep infiltrating endometriosis are at a significantly higher risk of developing ovarian cancer.
- Endometriosis affects approximately 11% of reproductive-aged women, with significant impacts on pelvic pain, infertility, and potential comorbidities such as ovarian, breast, and endometrial cancers.
- While there is a strong association between endometriosis and low-grade serous ovarian cancer, consistent links to high-grade serous or mucinous tumors are lacking.
- Data from the Utah Population Database indicated an overall increased risk of ovarian cancer in women with endometriosis, with hazard ratios ranging from 2.70 to 18.76 depending on the cancer histotype.
- The study highlights the necessity for further research to better understand the biological mechanisms linking endometriosis and ovarian cancer, aiming to improve prevention and treatment strategies.
Approximately 11% of reproductive-aged women are estimated to be impacted by endometriosis, including 50% to 60% of women and teenage girls with pelvic pain and up to 50% of women with infertility. Alongside pelvic pain and infertility, ovarian, breast, and endometrial cancers have been theorized as comorbidities linked to endometriosis.
Endometriosis has multiple significant impacts on women’s health, including mental, menstrual, urinary, bowel, and other nonspecific symptoms.2 One study reported a 67% increased risk of constipation in women with endometriosis, as well as a 46% increased risk of hemorrhoids or piles and 25% increased risk of indigestion or heartburn.
While associations have been reported between endometriosis and low-grade serous ovarian cancer, consistent associations were not determined for high-grade serous or mucinous tumors.1 Associations have also not been determined between ovarian cancer and endometriosis subtypes.
Investigators conducted a study to evaluate the association between endometriosis and endometriosis subtypes with ovarian cancer incidence overall and by histotype. Data was obtained from the Utah Population Database (UPDB), a comprehensive, population-based data resource.
A retrospective cohort was developed using UPDB data. Participants included women aged 18 to 55 years with at least 1 diagnosis of endometriosis. Inpatient records, statewide ambulatory surgery records, University of Utah electronic health records (EHRs), and Intermountain Health EHRs were assessed to identify diagnoses.
Endometriosis had an observed prevalence of 6.3%, fitting previous estimates. Categories of endometriosis included superficial peritoneal endometriosis, ovarian endometriomas, deep infiltrating endometriosis, ovarian endometriosis, and concurrent deep infiltrating endometriosis.1
Women with a history of endometriosis were matched 1:5 with unexposed women. Ovarian cancers diagnosed between 1992 and 2019 recorded in the Utah Cancer Registry were assessed as the primary outcome and included high-grade serous, low-grade serous, endometrioid mucinous, clear cell, carcinosarcoma, and other.
Women without a history of endometriosis were evenly distributed among the 5 most commonly evaluated histotypes. Covariates included race and ethnicity, sex, birth location, birth month and year, birth residence, death month and year, and last month and year with Utah residence.
Participants were aged a mean 36 years at first endometriosis diagnosis and had a mean follow-up duration of 12 years. Of participants, 75% were parous and 6% received a bilateral oophorectomy during follow-up. Nulliparity and undergoing a hysterectomy were more common in women with endometriosis than those without endometriosis.1
All ovarian cancer histotypes were more common in women with endometriosis, with adjusted hazard ratios (aHRs) ranging from 2.70 for high-grade serous ovarian cancer to 11.15 for clear cell carcinoma. An overall aHR of 4.20 was reported for ovarian cancer in women with endometriosis vs women without endometriosis.
Women with deep infiltrating endometriosis or ovarian endometriomas had the highest risk of ovarian cancer. Deep infiltrating endometriosis had an aHR of 18.76, and deep infiltrating endometriosis and concurrent ovarian endometriomas had an aHR of 13.04.1
The strongest association between endometriosis subtypes and ovarian cancer historypes was found between deep infiltrating endometriosis or ovarian endometriomas with type 1 ovarian cancer, with an aHR of 18.96. However, all endometriosis subtypes were associated with increased risks of type 1 and type 2 ovarian cancer.
Excess risk of ovarian cancer was identified in 9.90 women with endometriosis per 10,000. For the overall association, a bias-adjusted hazard ratio of 8.29 was reported.
These results indicated a significantly increased risk of ovarian cancer among women with endometriosis. Investigators recommended future studies work to improve characterization of the biology underlying these associations.1
Reference
- Barnard ME, Farland LV, Yan B, et al. Endometriosis typology and ovarian cancer risk. JAMA. 2024. doi:10.1001/jama.2024.9210
- Krewson C. Understanding endometriosis: Impact on women's health, symptoms. Contemporary OB/GYN. November 13, 2023. Accessed July 17, 2024. https://www.contemporaryobgyn.net/view/understanding-endometriosis-impact-on-women-s-health-symptoms
