Role of adjuvant radiotherapy modality on clinical outcomes for early-stage uterine carcinosarcoma

Background. There are limited data around adjuvant radiotherapy following surgical management for patients with early-stage uterine carcinosarcoma (UCS). We compared outcomes for patients with early-stage UCS who underwent adjuvant chemotherapy (CT) and pelvic external beam radiotherapy (EBRT) vs. CT and vaginal brachytherapy (VBT) vs. radiation therapy (EBRT or VBT) alone. Methods. A retrospective analysis was performed of patients diagnosed with FIGO stage I-II UCS from 2002 to 2020 who received adjuvant radiotherapy, with or without CT, following definitive surgery. Clinical and treatment characteristics and clinical outcomes were assessed. Kaplan-Meier method and log-rank test was used for clinical outcomes. Cox proportional-hazards modeling was used for multivariable analysis. Results. 98 patients were analyzed, of whom 38 received CT + EBRT, 31 received CT + VBT, and 29 received RT-alone (18 EBRT, 11 VBT). For the CT + EBRT, CT + VBT, and RT-alone groups, median follow up was 93.5, 50.2, and 143.0 months, and 3-year PFS was 78.7 %, 67.6 %, and 58.2 %, respectively. CT + EBRT was associated with improved PFS compared to RT alone (p = 0.01), but not compared to CT + VBT (p = 0.22). There were 4 locoregional recurrences in the CT + EBRT group (10.5 %), 8 in the CT + VBT group (25.8 %), and 5 in the RT-alone group (17.2 %). On multivariable analysis, RT-alone trended towards shorter time to progression (TTP) compared to CT + EBRT (p = 0.05), with similar TTP compared to CT + VBT (p = 0.83). Conclusions. In one of the largest retrospective cohorts of early-stage UCS, adjuvant CT + EBRT, but not CT + VBT, improved outcomes compared to RT-alone. Larger prospective studies are needed to investigate the role of different radiation modalities in UCS. (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar tech- nologies.