LAUSR

11051 Background: Uterine sarcomas are associated with poor prognosis snce the complete remission is extreme rare. Therefore, treatment with chemotherapy including eribulin or trabectedin, hormone therapy or molecular-targeted therapy including pazopanib or olaratumab was expectd, but the effect is not satisfactory. Thus, we evaluated the effects of temozoromide (T), derivateives of dacarbazine, and bevacizumab (B) (TB) containing or not cabozantinib (C), a multikinase inhibitor of MET, AXL, RET and VEGFR2 (TBC) in heavily pretreated cases of uterine sarcomas. Methods: From 2009 to 2018, 29 patients (pts) with heavily pretreated uterine sarcomas were enrolled. Fifteen of 29 patients were treated with T (80mg/body/day) and B (2mg/kg; days1, 8 and 15, q 4 weeks) (TB). Since 2013, C (140mg/body/week) was added to TB (TBC, n = 14). Treatment was continued until disease progression and/or unmanageable toxicities. Response was evaluated with the response evaluation criteria in solid tumors (RECIST) v1.1, and adverse events were assessed by common terminology criteria for adverse events (CTCAE) v4.0. Results: Seven pts (24 %) had carcinosarcoma, fifteen (52 %) had leiomyosarcoma, five (17 %) had undifferentiated uterine sarcoma, one (3 %) had adenosarcoma, and one (3 %) had uterine sarcoma-not other specified. Twenty-three of 29 pts were subjected to response evaluation. Five pts (22 %) had complete response (CR), three (13 %) had partial response, six (26 %) had stable disease (SD). The response rate (RR: CR+PR) and disease-control rate (DCR: CR+PR+SD) were 35 % and 70 %, respectively. The median progression-free survival was 6.5 (2-89) months. When adding C to T and B, DCR was improved from 64 % (TB) to 75% (TBC). Median administration of cycles is 7 (TB) and 5 (TBC). There were 2 dead cases from perforation, but toxicity was almost mild and manageable. Conclusions: We have experienced 5 cases of CR by TB or TBC. Moreover, addition of C to T and B resulted in better disease-control rate. Compared to other reported treatment, TB combined with C could be substantially effective in cases with heavily pretreated uterine sarcomas. These results warrant further prospective and randomized studies.