Abstract
BACKGROUND: To explore the risk factors of endometriosis-associated ovarian cancer (EAOC) in women with ovarian endometriosis (OEM) aged 45 years and above in China. METHODS: This study reviewed the medical records of 1038 women in total who were aged 45 years and above, surgical-pathologically diagnosed with ovarian endometriosis, and were treated at Peking Union Medical College Hospital between December 1996 and December 2016. Histology evaluation was used to determine whether the ovarian endometriosis specimen was with (n = 30) or without (n = 1008) ovarian cancer. RESULTS: 2.9% (30/1038) of women with the surgical-pathological diagnosis of ovarian endometriosis were found to have EAOC. Those patients with EAOC were prone to be in the postmenopausal status at the time of the diagnosis (OR 5.50, 95%CI 2.54-11.90, P < .001) and larger size of tumor (≥8 cm, OR 7.19, 95% CI 3.34-15.50, P < .001), and higher prevalence of coexisting with endometrial disorders (OR 4.11, 95%CI 1.73-9.73, P = .003). This study showed that patients of an older age when diagnosed with OEM, were at a higher risk of developing EAOC, respectively measuring of 1.7% (13/751) at 45-49 years, 5.6% (12/215) at 50-54 years, and 10.0%(5/50) at 55-59 years (P < 0.001). CONCLUSIONS: This study showed that for women aged 45 years and above who were diagnosed with OEM, the independent risk factors of EAOC were menopausal status, tumor size of 8 cm or greater in diameter, and coexisting endometrial disorders. Therefore, intensive follow-ups or active interventions should be considered for them.