Prognostic value of the TCGA molecular classification in uterine carcinosarcoma

Background: The TCGA molecular groups of endometrial carcinoma are "POLE-mutated" (POLEmut), "microsatellite-instable/mismatch repair-deficient" (MSI/MMRd), "TP53-mutated/p53-abnormal" (TP53mut/p53abn), and "no specific molecular profile" (NSMP). Objective: Prognostic assessment of the TCGA groups in uterine carcinosarcoma (UCS). Search strategy: Systematic review from January 2000 to January 2021. Selection criteria: Studies assessing the TCGA groups in UCS. Data collection and analysis: Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier and Cox analyses (reference: TP53mut/p53abn group) and compared with endometrioid and serous carcinomas (original TCGA cohort), with a significant P < 0.050. Main results: Five studies with 263 UCS were included. Compared with TP53mut/p53abn UCS, MSI/MMRd UCS showed significantly better PFS (P < 0.001) but similar OS (P = 0.788), whereas NSMP UCS showed similar PFS (P = 0.936) and OS (P = 0.240). Compared with their endometrioid/serous counterparts, NSMP and TP53mut/p53abn UCS showed significantly worse PFS (P < 0.001 and P = 0.004) and OS (P < 0.001 and P < 0.001), while MSI/MMRd UCS showed similar PFS (P = 0.595) but significantly worse OS (P < 0.001). The POLEmut group showed neither recurrences nor deaths in both the UCS and the endometrioid/serous carcinoma cohorts. Conclusion: POLEmut UCS show excellent prognosis, whereas TP53mut/p53abn and NSMP UCS show a prognosis even worse than that of TP53mut/p53abn endometrioid/serous carcinomas. The prognosis of MSI/MMRd UCS remains to be defined.