Impact of chemotherapy in uterine sarcoma (UtS): review of 13 clinical trials from the EORTC Soft Tissue and Bone Sarcoma Group (STBSG) involving advanced/metastatic UtS compared to other soft tissue sarcoma (STS) patients treated with first line chemotherapy.

Objective: UtS are a group of uncommon tumors representing 1% of malignant neoplasms of the female genital tract, and 7% of sarcomas. The objective of this study was to evaluate the factors associated with the clinical behavior UtS.

Methods: Information on 269 patients with advanced or metastatic first line UtS treated by chemotherapy was available in a database containing information on 3270 patients with advanced soft tissue sarcomas (STS) entered in EORTC-STBSG clinical trials between 1977 and 2010. The chemotherapy was aggregated in 4 categories: anthracyclines alone, ifosfamide alone, the combination of doxorubicin and ifosfamide, and CYVADIC.

Results: Among the 269 UtS pts, there were 231 deaths (median OS 10.4months, 95% CI: 9.1-11.9) and 257 progressions and/or deaths (median PFS 4.1months, 95% CI: 3.5-4.9). Multivariate analyses reported PS (p<0.001) only to be a statistically significant prognostic factor for OS in UtS; for PFS, LMS histology (p=0.025) is associated with a better outcome. There was no relationship between the 4 groups of chemotherapy regimens and impact on clinical outcomes. Histological subtype was significantly correlated with response to chemotherapy (RR: LMS 19% vs other 33%, p=0.026). Ifosfamide single agent yielded only 5% of RR.

Conclusions: Clearly, UtS are very aggressive neoplasms with poor outcome when treated with chemotherapy consisting of anthracyclines with or without ifosfamide or cyclophosphamide. New strategies are urgently needed.