Single Institute Experience Treating Uterine Carcinosarcoma: Outcome Analysis

Abstract

Uterine carcinosarcoma (UCS) is rare with a poor prognosis. We report over 10 years' experience, reporting prognostic and predictive factors for overall survival (OS) and disease-free survival (DFS). Patient, tumor, treatment and relapse characteristics of 168 women with stages I-IVB UCS treated at our institute between 2010 and 2020 were analyzed. OS and DFS at 2 and 5 years were the primary outcomes, estimated with Kaplan-Meier. The benefit of adjuvant chemotherapy and radiotherapy in the curative cohort was estimated using the log rank test. Median follow up was 23 months (range 1-137 months). 34% had FIGO stage IA disease, 10% IB, 8% II. 16% IIIA-IIIC1, and 10% IIIC2 and 22% IVB. The overall 2-year OS was 52% and 5-year OS 30%. 2-year OS by FIGO stage were: IA 66%; IB 63%; II 54%; IIIA-IIIC1 54%; IIIC2 45%; IVB 26%. Within the curative cohort who were surgically staged, 2-year DFS was 47% and 5-year was 30%. 2-year DFS were 61% in IA disease, 53% IB, 12% II, 51% IIIA-IIIC1, and 45% IIIC2 and 4% IVB. A greater risk of death was conferred by lack of adjuvant treatment (lack of chemo > lack of radiotherapy). The most common chemotherapy regimen used was Carboplatin Paclitaxel and pelvic radiotherapy 45Gy 25F over 5 weeks. The combination of surgery and chemotherapy +/- radiotherapy significantly improved OS compared to surgery +/- radiotherapy (HR 0.5 with CI 0.3 - 0.9) p<0.05. Radiotherapy improved OS compared to surgery only (HR 0.4 with CI 0.2 - 1.1) p<0.05. Relapse rate in all patients following curative treatment is 72% within year 1 and 86% within year 2 from diagnosis. In 52 patients with stage 1A disease treated with surgery +/- radiotherapy only, 42.4% relapsed, median time to relapse was 8 months from diagnosis. Relapse occurred despite 69.2 % stage 1A patients receiving adjuvant pelvic EBRT and in these patients relapse within the pelvis occurred in 50%. This study constitutes the largest retrospective analyses of long-term mortality outcomes in UCS and confirms poor outcomes despite curative surgery and adjuvant therapy. Most patients relapse within the first year following curative treatment. The use of adjuvant chemotherapy improves OS in all stages. In stage 1A disease 42 % patients relapse locally and distantly. This is an area of controversy and this data would strongly suggest that the addition of adjuvant paclitaxel-carboplatin or cisplatin-doxorubicin chemotherapy to EBRT should be considered in all patients including earliest stage disease.