Survival outcomes and prognostic factors of endometrial stromal sarcoma and undifferentiated uterine sarcoma

To review the diagnostic and therapeutic procedures of patients diagnosed with Endometrial Stromal Sarcoma (ESS) and Undifferentiated Uterine Sarcoma (USS) at our institution and investigate their clinical outcomes and factors affecting prognosis.

We retrospectively collected demographic data, preoperative diagnostic methods and therapeutic management of patients treated for ESS and UUS between January 1995 and December 2019 at Vall d'Hebron Barcelona Hospital Campus, Spain. Overall survival and disease-free survival were calculated. Cox proportional-hazards regression models were calculated.

Sixty-three patients were included in the study, of which 51(81%) had a diagnosis of ESS and 12(19%) of UUS. Twenty patients (31.7%) were diagnosed after a previous non-oncologic surgery, and 12 of them (60%) suffered from tumor disruption. Cytoreductive procedures were needed in 29 patients (46%), and optimal cytoreduction was achieved in 80.9% of the patients. The median follow-up was 7.6 years (IQR = 0.99-14.31). Five-year overall survival was 57.6% (44.2-68.8) and was significantly better for low-grade ESS (LG-ESS) patients (p < 0.01). Five-year disease-free survival was 57.1% (42.8-69.1) and was also significantly higher in LG-ESS cohort (p = 0.03). After multivariate analysis histological type, age, FIGO stage, optimal surgery and mitotic index were found significantly correlated with survival. For high-grade EES (HG-ESS) and USS patients adjuvant radiotherapy also correlated with improved survival.

Overall survival and disease-free survival are significantly better in patients with LG-ESS cohort. HG-ESS and UUS show similar survival outcomes. Age, FIGO stage, optimal surgery and histological type were significantly correlated with survival in the global cohort, whilst adjuvant radiotherapy correlated with improved survival in HG-ESS and UUS patients.