822TiP BFR ESS: A randomized phase II trial from the GSF/GETO French group evaluating the impact of interruption versus maintenance of aromatase inhibitors in patients with advanced or metastatic low grade endometrial stromal sarcoma after at least 3 years of therapy

Abstract

Uterine sarcomas are rare tumors with an incidence of 1.7/100 000 women per year, including 20% of endometrial stromal sarcomas (ESS). Patients (pts) with low grade ESS (LGESS) have a good prognosis with 5-year overall survival rates ranging from 66 to 98%, depending on the stage of the disease. Unlike undifferentiated endometrial sarcoma (UES), which behave aggressively, LGESS are indolent. For advanced or metastatic stage, hormonal therapy (HT) is the standard of care. The use of HT for advanced or metastatic disease is recommended based on retrospective data from small series providing evidence that HT have an anti-tumor activity on LGESS.