Leiomyosarcomas may originate from pre-existing uterine fibroids. However, recent studies showed that leiomyosarcomas do not arise from malignant changes in fibroids. Epidemiological data on the long-term risk of uterine malignancy with uterine fibroids are lacking. We aimed to determine whether uterine fibroids are a risk factor for uterine cancer. Patient data (2007-2020) from the Korean Health Insurance program were obtained. Using the procedure and diagnostic codes, data from patients who underwent myomectomy and appendicitis (control group) were extracted Using 1:1 propensity-score matching, 84,507 women were each allocated to the uterine fibroids and control groups. Endometrial cancer occurred in 36 44 and 44 36 women in the uterine fibroids and control groups (