Uterine carcinosarcoma vs endometrial serous and clear cell carcinoma: a systematic review and meta-analysis of survival

Background: It is unclear whether uterine carcinosarcoma (UCS) is more aggressive than endometrial serous carcinoma (SC) and clear cell carcinoma (CCC). Objectives: To compare the prognosis of UCS to that of endometrial SC and CCC, through a systematic review and meta-analysis. Methods: Four electronic databases were searched from January 2000 to October 2020. All studies assessing hazard ratio (HR) for death in UCS vs SC and/or CCC. HRs for death with 95% confidence interval were extracted and pooled by using a random-effect model. A significant P-value <0.05 was adopted. Results: Six studies with 11 029 patients (4995 with UCS, 4634 with SC, 1346 with CCC and 54 with either SC or CCC) were included. UCS showed a significantly worse prognosis than SC/CCC both overall (HR = 1.51; P = 0.008) and at early stage (HR = 1.58; P < 0.001). Similar results were found for UCS vs SC (HR = 1.53; P < 0.001) and UCS vs CCC (HR = 1.60; P < 0.001). Conclusions: Compared to SC and CCC, UCS has a significantly worse prognosis, with a 1.5–1.6-fold increased risk of death. This might justify a more aggressive treatment for UCS compared to SC and CCC. Further studies are necessary to define the prognostic impact of different molecular subgroups.