Different Patterns of Disease Spread between Advanced-Stage Type i and II Epithelial Ovarian Cancer

Two types of epithelial ovarian carcinoma (EOC) have been recently distinguished. Type I comprises low-grade serous, endometrioid and clear-cell tumors. High-grade endometrioid and serous tumors belong to type II. The aim of this study was to compare patterns of disease spread in advanced-stage type I and II EOCs at primary surgery. Methods: Surgical and pathological data of 233 patients with advanced-stage EOCs were collected, 42 with type I and 191 with type II. The two groups were compared for tumor localization at primary surgery. Intraoperative mapping of ovarian cancer (IMO) was used to assess tumor dissemination. Results: Tumor involvement was significantly higher in the type II group for the following: peritoneum (68.1 vs. 40.5%, p < 0.001), pouch of Douglas (60.2 vs. 40.5%, p = 0.06), vesicouterine ligament (40.8 vs. 19%, p = 0.027), diaphragm (45.0 vs. 11.9%, p < 0.001), serosa of liver (17.2 vs. 4.8%, p = 0.05), omentum (81.1 vs. 59.5%, p = 0.007), mesentery (42.9 vs. 16.7%, p = 0.005), pleural effusions (19.4 vs. 4.6%, p = 0.01) and ascites (60.7 vs. 21.4%, p < 0.001). IMO levels were different between the two groups (p = 0.001). Conclusions: This study provides clinical evidence in favor of the dualistic model of carcinogenesis, since types I and II are characterized by different findings at primary surgery.