Does the Presence of Endometriosis Affect Prognosis of Ovarian Cancer?

Ovarian cancers diagnosed between 2000 and 2013 were examined and cases with and without endometriosis compared. Among 139 epithelial ovarian, there were 49 (35%) with endometriosis and 90 (65%) without endometriosis. Endometriosis associated ovarian cancers were more likely to be confined to the pelvis (54% vs. 9%, p < 0.0001) and lower grade (51% vs. 29%, p = 0.014). Younger age and earlier stage independently predicted the presence of endometriosis (p = 0.0011 and p < 0.0001, respectively). Ovarian cancer patients with endometriosis had improved PFS and OS [(HR = 0.20; 95% CI, 0.09-0.43), (HR = 0.18; 95% CI, 0.04-0.81)], compared to patients without endometriosis; however, endometriosis had no independent prognostic significance.