Key takeaways:

• Women with vs. without endometriosis had significantly higher odds of ovarian and endometrial cancers.
• Endometriosis was tied to lower risk for breast cancer and had no association with cervical cancer.

Endometriosis was significantly associated with higher risks for both ovarian and endometrial cancers, but was not significantly associated with cervical cancer risk, according to an analysis published in Current Oncology.

“Genomic data from cancer studies have unveiled genetic connections between endometriosis and various female cancers, namely breast, cervical, endometrial and ovarian cancers,” Ismail Abdulrahman Al-Badawi, MD, from the department of obstetrics and gynecology at King Faisal Specialist Hospital and Research Center and the College of Medicine at Al Faisal University, Saudi Arabia, and colleagues wrote. “Moreover, accumulating research from various high-hierarchy systematic review and meta-analysis reports of case-control and cohort studies has documented correlational relationships between endometriosis and certain gynecologic cancers.”

Al-Badawi and colleagues evaluated data from 226,487 women with gynecologic cancer from the U.S. National Inpatient Sample database from 2016 to 2019. Of these women, 1,164 had endometriosis. Researchers analyzed associations between endometriosis and breast, ovarian, endometrial and cervical cancers.

Women with endometriosis had higher rates of ovarian (46.56% vs. 20.28%) and endometrial (34.27% vs. 13.46%) cancers compared with women without (P < .05 for both). Conversely, women with vs. without endometriosis had lower breast cancer rates (14.34% vs. 59.04%; P < .05). Researchers observed no significant difference in cervical cancer rates between women with and without endometriosis (8.68% vs. 8.32%).

In the univariate analysis, endometriosis was associated with higher risks for ovarian (OR = 3.42; 95% CI, 3.05-3.84; P < .001) and endometrial (OR = 3.35; 95% CI, 2.97-3.79; P < .001) cancers and was associated with lower breast cancer risk (OR = 0.12; 95% CI, 0.1-0.17; P < .001). Endometriosis was not significantly associated with cervical cancer risk (OR = 1.05; 95% CI, 0.85-1.28).

In the multivariate analysis, endometriosis remained associated with higher risks for ovarian (adjusted OR = 3.34; 95% CI, 2.97-3.75; P < .001) and endometrial (aOR = 3.61; 95% CI, 3.12-4.08; P < .001) cancers and was associated with lower breast cancer risk (aOR = 0.12; 95% CI, 0.11-0.15; P < .001). In addition, researchers continued to observe no significant association between endometriosis and cervical cancer risk.

“All in all, these findings emphasize the importance of tailored health care management for individuals with endometriosis, considering their unique cancer risk profiles. Notably, the present analysis does not provide causative risks, which would require clinical validation, but observes potentially relevant associations,” the researchers wrote. “Further research is warranted to unravel the underlying mechanisms driving this connection.”