508P Prognostic factors of soft tissue sarcoma (STS) treated with pazopanib from Nishinomiya Sarcoma Cohort Study (NSCS)

Background Pazopanib was approved in 2012 in Japan. We established the Japan Sarcoma Association and we built up the nationwide multidisciplinary therapeutic consortium. Nishinomiya carries the center of chemotherapy. Methods We conducted a retrospective analysis on pazopanib for soft tissue sarcoma (STS) in order to examine the relationship of pazopanib treatment and overall survival (OS). In this study, patients with metastatic STS treated with pazopanib from November 2012 till August 2015, consecutively, were retrospectively analyzed as data of NSCS. Results One hundred six pts (57 leiomyosarcomas, 10 liposarcomas, 39 other subtypes) were identified. Median age was 56 years old (range 17-84), 83 females and 23 males and 51 pts were treated in the first-line setting. Median OS reached 16.9 months (95% CI: 12.8-30.8) and median PFS was 2.9 months (95%CI: 2.3-4.0). OS with leiomyosarcoma was 22.8 months and others was 14.5 months. OS in 1st line setting reached 26.2 months. OS in CR was 26.2 months, that in PR was 22.8 months and that in PD was 11.5 months. According to primary site, PFS generated from uterus was 2.2 months, that from GI tract was 3.0 months and that from other organs was 4.1 months (p=0.034). From the viewpoint of long term prognosis, seventeen long survivors (LS) over 2 years were detected. RR of them was 35.3% but that of seventeen short survivors (SS) within 6 months was 5.9% (p=0.033). Furthermore, SUVmax value of LS by FDG PET-CT before pazopanib treatment was 3.9 (2.2-8.4) and it was lower than that of SS (15.4 (4.8-23.7), p=0.0034). Conclusions Pazopanib including first-line setting for metastatic STS is safe and effective. PET-CT before pazopanib treatment is possibly prognostic. The further examination of neovascularization and hypoxia are warranted. Legal entity responsible for the study Hiroyuki Narahara Funding Japan Sarcoma Association Disclosure All authors have declared no conflicts of interest.