Role of CA125/CEA ratio and ultrasound parameters in identifying metastases to the ovaries in patients with multilocular and multilocular-solid ovarian masses

Objectives: To investigate ultrasound features and the best cut-off value of the cancer antigen 125/carcinoembryonic antigen (CA125/CEA) ratio to discriminate ovarian metastases from benign and primary malignant ovarian neoplasms in two selected groups of morphological ovarian masses, namely multilocular masses with five or more locules and multilocular-solid masses. Methods: Patients with multilocular (five or more locules) or multilocular-solid ovarian masses, operated on within 3 months of ultrasound examination, and with tumor markers (CEA and CA125) available at diagnosis, were identified retrospectively from three ultrasound centers. The masses were described using the International Ovarian Tumor Analysis (IOTA) terminology. Ultrasound and clinical characteristics were compared between those with an ovarian neoplasm (including benign and primary malignant neoplasms) and those with an ovarian metastasis. Receiver–operating characteristics curve (ROC) analysis was used to evaluate the ability of CA125, CEA and CA125/CEA to differentiate between ovarian neoplasms and ovarian metastases, and their predictive performance was assessed. Results: In total, 350 (88.4%) patients with an ovarian neoplasm (including 99 benign, 43 borderline and 197 primary epithelial ovarian carcinomas, seven malignant rare tumors and four other types of invasive ovarian tumor) and 46 (11.6%) patients with an ovarian metastasis were analyzed. On ultrasound examination, ovarian neoplasms were smaller than ovarian metastases (median largest diameter, 97 (range, 20–387) mm vs 146 (range, 43–259) mm, respectively; P < 0.0001) and presented with a lower number of cysts with > 10 locules (18.9% vs 54.3%; P < 0.0001). ROC curve analysis showed that the best cut-off value of CEA for distinguishing between ovarian neoplasms and ovarian metastases was 2.33 ng/mL. The predictive performance of this CEA cut-off value was: area under the curve (AUC), 0.791 (95% CI, 0.711–0.870); accuracy, 73.