Background: Uterine sarcomas are a group of mesenchymal tumours comprising several histologies. They have a high recurrence rate following surgery, modest outcome to systemic therapy, and poor overall survival. Pazopanib is a multi-targeted tyrosine kinase inhibitor approved for non-adipocytic advanced soft tissue sarcomas (STS). Here we investigated whether response to pazopanib in patients with uterine sarcomas differs from that of patients with non-uterine sarcomas. Patients and methods: Uterine sarcoma patients were retrieved from all soft tissue sarcoma patients treated with pazopanib in EORTC Phase II (n = 10) and Phase III (PALETTE) (n = 34) studies. Patient and tumour characteristics, response, progression free and overall survival data were compared. Results: Forty-four patients with uterine sarcoma were treated with pazopanib. The majority of patients had uterine leiomyosarcoma (LMS) (n = 39, 88.6%) with high grade tumours (n = 37, 84.1%) compared to 54.8% (n = 164) in the non-uterine population. The median age was 55. years (range 33-79) and median follow up was 2.3. years. Uterine patients were heavily pre-treated, 61.3% having ≥. 2 lines of chemotherapy prior to pazopanib compared to 40.8% in the non-uterine population. Five patients (11%), all LMS, had a partial response (95% CI 3.8-24.6). Median progression free survival (PFS) 3.0. months (95% CI 2.5-4.7) in uterine versus 4.5 (95% CI 3.7-5.1) in non-uterine STS. Median overall survival (OS) was 17.5. months (95% CI 11.1-19.6), longer than the non-uterine population, 11.1. months (95% CI 10.2-12.0) (p = 0.352). Conclusions: Despite heavy pre-treatment, pazopanib shows signs of activity in patients with uterine sarcoma with the similar outcomes to patients with non-uterine STS.

Pazopanib, Soft tissue sarcoma, Uterine sarcoma,
Gynecologic Oncology
Erasmus MC: University Medical Center Rotterdam

Benson, C, Ray-Coquard, I, Sleijfer, S, Litière, S, Blay, J.Y, le Cesne, A, … van der Graaf, W.T.A. (2016). Outcome of uterine sarcoma patients treated with pazopanib: A retrospective analysis based on two European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) clinical trials 62043 and 62072. Gynecologic Oncology, 142(1), 89–94. doi:10.1016/j.ygyno.2016.03.024