Endometriosis Typology and Ovarian Cancer Risk.
Level 3 - non-randomized controlled study
Matched population-based retrospective cohort study.
PubMed 39018030 · doi:10.1001/jama.2024.9210
What was done
Researchers conducted a population-based matched cohort study using the Utah Population Database, matching 78,893 women with electronic health record diagnoses of endometriosis in a 1:5 ratio to unexposed women (total N = 473,358). Endometriosis was categorized as superficial, ovarian endometriomas, deep infiltrating, or other. Cox models estimated adjusted hazard ratios (aHRs) and adjusted risk differences (aRDs) per 10,000 women for overall ovarian cancer, type I, and type II ovarian cancers, adjusting for sociodemographic factors, reproductive history, and past gynecologic operations.
What was found
Among the cohort (mean age at diagnosis 36 years), 597 women developed ovarian cancer. Overall, endometriosis was associated with higher ovarian cancer risk (aHR 4.20, 95% CI 3.59-4.91; aRD 9.90 per 10,000, 95% CI 7.22-12.57), primarily driven by type I ovarian cancer (aHR 7.48, 95% CI 5.80-9.65; aRD 7.53, 95% CI 5.46-9.61). The highest risks occurred in women with deep infiltrating endometriosis and/or ovarian endometriomas for all ovarian cancers (aHR 9.66, 95% CI 7.77-12.00; aRD 26.71, 95% CI 20.01-33.41), type I ovarian cancer (aHR 18.96, 95% CI 13.78-26.08; aRD 19.57, 95% CI 13.80-25.35), and type II ovarian cancer (aHR 3.72, 95% CI 2.31-5.98; aRD 2.42, 95% CI -0.01 to 4.85).
Why it matters
This study demonstrates that ovarian cancer risk varies substantially by endometriosis subtype, with the highest elevation concentrated in women with ovarian endometriomas or deep infiltrating disease. These findings provide a basis for risk stratification and targeted surveillance or counseling strategies.
Limits
Identification of endometriosis relied on electronic health record diagnosis codes rather than uniform surgical or histological confirmation for all participants, which may introduce misclassification bias. Residual confounding from unmeasured lifestyle or environmental factors remains possible, and the findings from a Utah population may have limited generalizability across more ethnically diverse populations.
Cited by
- supports Endometriosis carries a slightly increased risk of ovarian cancer, particularly in patients with endometriomas or advanced disease.