Prognostic impact of sarcomatous component in patients with localized and locally advanced uterine carcinosarcoma

Background: Uterine carcinosarcoma is a biphasic malignancy with a carcinomatous and a sarcomatous component, with a poor prognosis even in those treated with curative intent.

Objective: Evaluate the prognostic of the sarcomatous component (homologous versus heterologous) in patients with localized/locally advanced uterine carcinosarcoma.

Methods: This retrospective study evaluated patients with localized/locally advanced (FIGO I-IVA) uterine carcinosarcoma treated at a single cancer center (2003 – 2024). The endpoints were overall survival (OS) and disease-free survival (DFS) according to the sarcomatous component. The Kaplan-Meier method was used for survival analyses. Hazard ratio (HR) and 95% confidence interval (95% CI) were calculated using Cox regression.

Results: 61 patients with localized/locally advanced disease (34 homologous vs 27 heterologous) were included. Among the heterologous group, the most common pathological subtype was Rhabdomyosarcoma (60%), while in the homologous group it was endometrial stromal sarcomas (95%). All patients underwent surgery. Adjuvant chemotherapy was indicated for approximately 70% of patients (mainly Carboplatin plus Paclitaxel). A difference was observed between patients who did not complete adjuvant chemotherapy: 23.5% vs. 40.7% patients in the homologous and in the heterologous groups, respectively (p = 0.03). The main reason for this was recurrence during treatment. In the whole series, the median OS was 56.2 months. When comparing the homologous vs. the heterologous group, the median DFS was 143.2 months vs. 18.0 months (HR 3.72, 95%CI 1.73 – 8.02; p = 0.001) and the median OS was 143.2 months vs. 34.4 months (HR 2.79, 95%CI 1.27 – 6.13; p = 0.001), respectively. In a multivariable analysis, heterologous subtype (HR 4.34, 95%CI 1.59 – 11.85, p = 0.004) and FIGO stage III (HR 3.33, 95%CI 1.18 – 9.39, p = 0.023) were identified as factors associated with inferior DFS and OS, while completing adjuvant chemotherapy (HR 0.22, 95%CI 0.07 – 0.69, p = 0.009) was associated with superior outcomes.

Conclusions: The sarcomatous component has a relevant prognostic impact in localized/locally advanced uterine carcinosarcoma. In this cohort, the heterologous component was associated with a worse DFS and OS. Other negative prognostic factors were FIGO stage III and not completing adjuvant chemotherapy.

Corresponding author: Daniel Santos Rocha Sobral Filho (e-mail: danielsobralfilho@hotmail.com).