Objective: This retrospective study aimed to evaluate the clinicopathological characteristics of carcinosarcoma, grade 3 endometrial endometrioid carcinoma (G3EEC), uterine serous carcinoma (USC), and uterine clear cell adenocarcinoma (CC) to determine whether carcinosarcoma exhibited the same characteristics and outcomes as the other 3 high-risk endometrial cancers.
Methods: A total of 358 patients recruited from the Obstetrics and Gynecology Hospital of Fudan University were included in this study; the cases included 44 carcinosarcomas, 118 G3EECs, 118 USCs, and 78 CCs. Kaplan-Meier and Cox proportional hazards models were used to analyze outcomes and prognostic factors.
Results: Uterine carcinosarcomas had significantly worse outcomes (overall survival, disease-specific survival, and recurrence-free survival) compared with G3EEC, USC, and CC (P < 0.001), whereas the other 3 shared similar outcomes. Carcinosarcoma type was an independent factor, even stratified by stage. Eighty-three percent of recurred carcinosarcoma patients occurred within 1 year. Compared with USC and CC, patients with carcinosarcoma had a greater incidence of deep myometrial invasion (55.8%, P < 0.05) and cervical stromal involvement (P = 0.046). The carcinomatous regions of carcinosarcomas demonstrated a similar ER/P53 expression pattern as did USC and CC. However, all features were similar in carcinosarcoma and G3EEC patients, although the P53-positive rate was higher in carcinosarcoma patients compared with G3EEC patients (59.0% vs 38.5%, P = 0.037). For carcinosarcomas, a multivariate analysis showed that advanced stage (P = 0.006) was an independent prognostic factor for disease-specific survival. With regard to endometrioid-or-not epithelial and heterologous-or-homologous sarcomatous components, none of these components demonstrated apparent relationship with prognosis.
Conclusions: Carcinosarcomas exhibited significantly poorer outcomes than did G3EECs, USCs, and CCs. Therefore, it seems reasonable to regard carcinosarcomas as a particular type among high-risk epithelial endometrial carcinomas.