Uterine carcinosarcoma and high-risk endometrial carcinomas: a clinicopathological comparison

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.

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.

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.

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.