Risk of ovarian cancer according to hormone replacement therapy in postmenopausal women with history of endometriosis or de-novo endometriosis

초록

Objective: The effect of hormone replacement therapy (HRT) on malignant transformation of postmenopausal endometriosis remains unclear. This study aimed to investigate the impact of HRT on ovarian cancer occurrence in postmenopausal women with a history of endometriosis or de-novo endometriosis. Methods: The data of 115,552 women diagnosed with endometriosis between 2008 and 2020 from the Korean Health Insurance Review and Assessment Service database were extracted. Among women who met the eligibility criteria, 10,304 women that received HRT (the HRT group) and 10,304 that did not (the control group) were selected using 1:1 matching (Figure 1). Results: Age at endometriosis diagnosis was younger in the HRT group than control group (48.9±5.8 vs 49.6±5.7 years, P <0.001). Duration of HRT was 1.4 ± 2.2 years. Incidences of ovarian cancer (0.3% in the HRT group vs 0.5% in the control group) and cumulative incidence rates of ovarian cancer were similar in the both groups. Times between endometriosis diagnosis and ovarian cancer diagnosis were not different in the both groups. Duration of HRT in women with ovarian cancer was 2.2±2.9 years. After adjustment for covariables, use of HRT, duration of HRT, use of combined estrogen and progesterone, and use of tibolone were not found to be risk factors of ovarian cancer. However, use of estrogen alone was a risk factor of ovarian cancer (HR 2.898; 95% CI 1.251?6.715; P = 0.013). Conclusions: HRT except estrogen alone did not increase risk of ovarian cancer in postmenopausal women with history of endometriosis or de-novo endometriosis.