Clinical outcomes from a retrospective registry of patients with locally advanced/metastatic synovial sarcoma and myxoid round cell liposarcoma.

Abstract

e22520 Background: Outcomes of patients (pts) with advanced synovial sarcoma (SS) and myxoid/round cell sarcoma (MRCL) is lacking. Current data is limited to single institution studies or post hoc analyses of clinical trials. To understand the natural history of these subtypes of soft tissue sarcoma we performed a systematic analysis of SS and MRCL patients from large medical institutions. Methods: Data was abstracted at 7 U.S. centers for pts treated from 2005 to 2015. Advanced SS or MRCL were eligible if they had received chemotherapy and were 18 years or older. The primary endpoint was overall survival, and secondary endpoints were progression free survival, time to next treatment, time to new distant metastasis. Results: 350 pts with locally advanced (LA), unresectable and/or or metastatic (Met) SS (n = 249) and MRCL (n = 101) were analyzed. The median age at diagnosis was 40 years for SS pts (58.2% male). The median age of MRCL pts was 50 years (67.3% male). 249 SS pts all had ≥ 1line of therapy, 74.7% had ≥2 lines of treatment. All MRCL pts received ≥1 line of treatment, 72.3% had ≥2 lines. The clinical outcomes (median overall survival (OS), progression free survival (PFS), time to next treatment (TTNT) and time to distant metastasis (TTDM)) from start of first-line chemotherapy are: The OS and PFS from second line chemotherapy decreased for all evaluable pts (n = 259) was 17.9 months (mos) [95% confidence interval (CI) (15.0, 22.3)]; 3.9 mos (3.4, 4.8), respectively. A similar trend toward shortened OS and PFS were seen with each subsequent line of chemotherapy. Conclusions: This registry analyzing real-world clinical outcomes among advanced SS and MRCL pts is the most comprehensive performed to date. It provides data on clinical outcomes depending on line of therapy and can provide the backbone for better patient management and design of future clinical trials.[Table: see text]