Abstract: Objective：To investigate the clinical and prognostic characteristics of endometriosis-associated ovarian cancer (EAOC). Methods：One hundred and thirty-nine patients with epithelial ovarian cancer [ovarian clear cell carcinoma (OCCC) and ovarian endometrioid carcinoma (OEC)] who were treated and operated in Dalian Maternity Hospital from January 2004 to July 2017 were selected according to whether they were complicated with ovarian endometriosis (EMs) were divided into EAOC group (41 cases) and the other into non-EAOC group (98 cases), the clinical data were retrospectively analyzed and follow-up prognosis. Results：The onset age and the age of menarche in EAOC group were lower than those in non-EAOC group (all P＜0.05). The proportion of non-menopausal patients in EAOC group was higher than that in non-EAOC group ( χ2=5.806, P=0.023). The distribution of pregnancy was different, EAOC group was lower than non-EAOC group ( χ2=3.206, P=0.001). The incidence of dysmenorrhea and menstrual disorders in EAOC group was higher than that in non-EAOC group (all P＜0.05). Patients with non-EAOC had more abdominal discomfort than patients with EAOC ( χ2=6.645, P=0.013). There was no significant difference between the two groups in the serum CA-125 value and the maximum diameter of the mass (all P＞0.05). The FIGO staging distribution was different in patients with EAOC and non-EAOC ( χ2=2.497, P=0.013). The 5-year survival rate of EAOC group was higher than that of non-EAOC group ( χ2=4.304, P=0.038). Two groups of patients Log rank analysis ( χ2=4.916, P=0.028). Conclusions：Ovarian EAOC patients compare to simple ovarian epithelial cancer patients have the lower diagnosed age and lower age of menarche, the higher proportion of non-menopause, lower birth rate, dysmenorrhea and obvious menstrual disorders, earlier FIGO stage and better prognosis.

Key words: Endometriosis, Ovarian neoplasms, Prognosis, Endometriosis-associated ovarian cancer