Population-based cohort study of risk of endometrial cancer and uterine sarcoma after endometriosis or pelvic inflammatory disease

The risk of uterine cancers after endometriosis or pelvic inflammatory disease (PID) is not clear. A population-based retrospective study in Taiwan included more than 270,000 patients with endometriosis or PID and age-matched controls. The follow-up was 6.8 years in the endometriosis cohort, 9.4 years in the PID cohort, and 9.1 years in the control cohort. The study showed that endometriosis, but not PID, was associated with elevated risk of both endometrial cancer and uterine sarcoma. The increased risk of uterine cancer in endometriosis patients persisted after propensity score matching (aHR 2.83; 95% CI 1.70-4.71).