Unraveling the two entities of endometrioid ovarian cancer: a single center clinical experience

Abstract

Objective: Due to the increasing prevalence of the benign condition, ovarian carcinoma arising from endometriosis is emerging as a relevant clinical entity with an unclear biological signature. We have investigated clinical and histologic features of endometriosis-associated endometrioid ovarian cancer using an institutional retrospective database.

Methods: Patients diagnosed with endometrioid ovarian cancer at our institution were divided into two groups according to the fulfillment or not of Sampson's and Scott's criteria for the detection of endometriosis-associated ovarian cancer. Clinical and histological data were reported and compared. Survival analysis was obtained using the log-rank test in an unadjusted Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression model to establish independent factors associated with endometriosis-associated endometrioid ovarian cancer and to identify predictors of survival. The degree of concordance was evaluated by Cohen's Kappa measures.

Results: Patients with endometriosis-associated endometrioid ovarian cancer were significantly younger, had a lower disease stage (62% vs 23%; p=0.003), a less prevalent high grade tumor (38% vs 82%; p=0.002) and a higher prevalence of squamous and mucinous metaplasia. The rate of endometrial cancer diagnosis was significantly higher in women with endometriosis-associated endometrioid ovarian cancer (33%) than in other patients (11%) (p=0.04) with a 92% concordance between ovarian and endometrial histologic tumor grade. A significant difference in survival rate could not be demonstrated between patients with or without endometriosis.

Conclusions: The analysis of a retrospective endometrioid ovarian cancer database may allow to suggest a 40 molecular, morphological and clinical parallelism between endometrial and endometrioid ovarian cancers.