Endometrial carcinosarcomas have a different prognosis and pattern of spread compared to high-risk epithelial endometrial cancer

OBJECTIVE: The endometrial origin of uterine carcinosarcoma has recently been well established. The current study investigates whether uterine carcinosarcomas can be included in protocols on high-risk endometrial cancer, given the similarities in biologic behavior of both entities. METHODS: Pathological and surgical notes of patients diagnosed with grade 3 endometrioid, carcinosarcoma, serous and clear cell endometrial cancer subtypes were retrospectively analyzed with special attention to the spread pattern of the different subtypes. Information on site of relapse and time to recurrence was obtained. RESULTS: We traced 146 patients of which 9 patients were ineligible. Histological subtypes of the remaining 137 patients were as follows: 50 (37%) grade 3 endometrioid carcinoma, 54 (39%) serous or clear cell carcinoma (non-endometrioid carcinoma), and 33 (24%) carcinosarcomas. Distribution of early stage disease (I and II) was 67, 46, and 78% for grade 3 endometrioid, non-endometrioid, and carcinosarcoma, respectively. Although we could not trace differences in hematogenic and transperitoneal spread among the three subtypes, non-endometrioid and carcinosarcomas were more likely to spread to pelvic and paraaortic lymph nodes (P