Background: This study describes clinical characteristics of a large cohort of aSTS patients (pts) and effectiveness of chemotherapy (CT) based on real world data. Methods: Multicenter retrospective cohort analysis using data from the French centers of the ESBCB (Conticabase.org) with an extraction in 2017. This study included adult pts with a diagnosis of sarcoma (WHO2013) between 2010 and 2013 in soft tissue or viscera, excluding GIST and Kaposi’s sarcoma. Results: 2747 pts were included with a diagnosis of STS. 34.6 % of them had an aSTS and were described in this study. Among them were 608 with secondary (metachronous) metastasis, 299 metastatic at diagnosis (synchronous) and 61 pts with locally aSTS, not amendable to surgery. The mean age at diagnosis was 59.3 years (+/- SD 16.9), 52.3% of pts were female and 21.2% had cancer of viscera. Most frequent sarcoma subtypes were undifferentiated sarcoma (24.9 %), leiomyosarcoma (23.8%) and miscellaneous sarcoma (14.7%). Sarcoma were grade 1 for 4.4%, 2 for 27.3% and 3 for 55.0 %, missing for 13.3%. Surgery for primary tumor was more frequent in the metachronous metastasis group than in the synchronous metastatic one (89.6% vs 41.5% respectively). At least one line of CT was administered to 56.9% and 61.2% pts with synchronous and metachronous metastasis, respectively. Anthracyclin-containing CT regimen were delivered in 63.6% of pts treated by first-line chemotherapy. Responses rates to first line chemotherapy were 30.6 % for pts with synchronous metastasis and 19.1 % for those with metachronous metastasis. For the entire aSTS population, the median overall survival was 1.45 years (95% CI : [1.23; 1.63]). The rates of overall survival (OS) at 3 years were 35.7% [22.2%; 49.3%] for pts with locally advanced disease, 29.4% [23.8%; 35.2%] for the pts with metachronous metastasis and 21.1 % [15.2%; 27.7%] for pts with synchronous metastasis.Conclusions: In this large nationwide database, therapeutic strategies and OS differed across groups of cancer diagnosis dates. These data are useful to provide real world treatment patterns and outcomes in a hard to study disease.