PT - JOURNAL ARTICLE AU - Jeong-Yeol Park AU - Dae-Yeon Kim AU - Dae-Shik Suh AU - Jong-Hyeok Kim AU - Yong-Man Kim AU - Young-Tak Kim AU - Joo-Hyun Nam TI - Significance of Ovarian Endometriosis on the Prognosis of Ovarian Clear Cell Carcinoma AID - 10.1097/IGC.0000000000001136 DP - 2018 Jan 01 TA - International Journal of Gynecologic Cancer PG - 11--18 VI - 28 IP - 1 4099 - http://ijgc.bmj.com/content/28/1/11.short 4100 - http://ijgc.bmj.com/content/28/1/11.full SO - Int J Gynecol Cancer2018 Jan 01; 28 AB - Introduction The aim of this study was to evaluate the significance of ovarian endometriosis on the prognosis of ovarian clear cell carcinoma (OCCC).Methods Patients with OCCC were divided into 2 groups according to the presence of ovarian endometriosis: group 1, no coexisting ovarian endometriosis; group 2, clear cell carcinoma arising from ovarian endometriosis or the presence of ovarian endometriosis elsewhere in the ovary. Clinicopathologic characteristics, disease-free survival (DFS), and overall survival (OS) were compared between the 2 groups.Results Of 155 patients with OCCC, 77 were categorized into group 1 and 78 into group 2. Group 2 patients were younger than group 1 (median age, 48 vs 51 years; P = 0.005) and had higher incidence of early-stage disease (stage I, 77% vs 58%; P = 0.001) and lower incidence of lymph node metastasis (4% vs 17%; P = 0.008). Group 2 patients were observed to have a significantly higher 5-year DFS (P < 0.001) and OS (P = 0.001) compared with group 1. In stage I disease, group 2 had a significantly higher 5-year DFS (P = 0.004) and OS (P = 0.016) than did group 1. In the multivariate analysis, coexisting endometriosis and advanced International Federation of Obstetrics and Gynecology stage were significant factors for both DFS and OS rates.Conclusions Ovarian clear cell carcinoma with endometriosis was found more frequently in younger women and had a higher incidence of early-stage disease and a lower incidence of lymph node metastasis compared with OCCC without endometriosis. Ovarian endometriosis was associated with improved prognostic factors and a better DFS and OS even in stage I disease. Ovarian endometriosis was an independent prognostic factor for OCCC.