Clinicopathological characteristics, treatment and outcomes in uterine carcinosarcoma and grade 3 endometrial cancer patients: a comparative study

OBJECTIVE: Uterine carcinosarcoma (UCS) shared the same staging system with endometrial carcinoma in the International Federation of Gynecology and Obstetrics 2009. The aim of the present study was to compare the clinicopathological and prognostic characteristics between UCS and grade 3 endometrioid endometrial carcinoma (G3EC). METHODS: A retrospective analysis of 60 UCS and 115 G3EC patients with initial treatment at the Department of Gynecology in the Fudan University Shanghai Cancer Center between February 2006 and August 2013. Chi-square analysis was used to compare differences between variables. Prognostic factors were determined using univariate/multivariate analysis, and the survival rates were assessed using the Kaplan-Meier method. The Cox regression model was used to assess the independent prognostic factor. RESULTS: UCS had significantly worse overall survival (OS) compared with G3EC. Carcinosarcoma subtype was an independent factor (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.0 to 5.8; p=0.039), stratified based on stage. Compared with G3EC, UCS patients had a greater incidence of ascites fluid (55.0% vs. 15.7%, p<0.001) and adnexal involvement (20.0% vs. 8.7%, p=0.048) and larger median tumor volume (4.6 cm vs. 4.0 cm, p=0.046). Subgroup analysis of the prognostic factors revealed that UCS patients exhibited worse OS than G3EC patients in such specific subgroups as patients at younger ages, with postmenopausal status, without ascites fluid, with early stage diseases, without vagina invasion, without lymph node metastases and receiving adjuvant chemo/radiotherapy. Adjuvant radiotherapy with chemotherapy was predictive of better survival in UCS patients compared with chemotherapy or radiotherapy alone (5-year OS, 71.0% vs. 35.8%, p=0.028). Multivariate Cox regression revealed that tumor mesenchymal component (HR, 4.6; 95% CI, 1.4 to 15.8; p=0.014) was an independent prognostic factor for UCS, whereas advanced stages (HR, 5.9; 95% CI, 1.0 to 33.9; p=0.046) and ascites fluid (HR, 5.1; 95% CI, 1.1 to 22.7; p=0.032) were independently correlated with poor prognosis for G3EC patients. CONCLUSION: The distinctions in both clinicopathological and prognostic characteristics between UCS and G3EC suggest that this subtype should be treated separately from high-risk epithelial endometrial carcinoma.