9520 Background: Advanced soft tissue sarcomas (aSTS) represent an incurable clinical entity of poor prognosis, in which chemotherapy is frequently viewed as relatively ineffective. We aimed to review the efficacy of palliative chemotherapy and investigate prognostic factors in a large group of patients treated on routine palliative protocols. Methods: Patients with STS who had first line chemotherapy for advanced and/or metastatic disease between 1991 and 2005 were identified from the Royal Marsden Hospital’s sarcoma database. Patients with Ewing’s sarcoma, rhabdomyosarcoma, desmoplastic small round cell tumour and GIST were excluded from the study. Patients who were treated elsewhere more than 1 year before they come to our hospital were also excluded. Results: 488 patients (242M/286F) fulfilled the criteria. Median age at the time of treatment was 50 years (range 19–79). The main tumour types were leiomyosarcomas (35%) synovial sarcoma (13%), liposarcoma (10%) and malignant fibrous histiocytoma (10%). The majority of patients (83%) received chemotherapy for metastatic disease. 71% of patients had single organ involvement and 29% had multiple disease sites. Lung was the most common site of metastasis (56%). 54% were treated with single agent chemotherapy. Response rate to chemotherapy was 33% (53% for synovial sarcoma); 22% achieved stable disease for a median duration of 8 months; 45% progressed through chemotherapy. Median time to progression was 3 months, duration of response 9 months and post treatment survival (OS) 12 months. In multivariate analysis, age <60, liposarcoma and synovial histology were found as positive and bone involvement as negative independent prognostic factors. Patients treated with combination chemotherapy experienced longer survival (11 vs 14 months OS; p=0.001). Conclusions: This retrospective study of standard palliative chemotherapy in unselected patients with aSTS shows that more than half of patients benefit from treatment, indicating that this is a worthwhile treatment option. Synovial sarcoma and liposarcoma represent the most chemosensitive sarcoma subtypes. Nevertheless, continuing search for new agents is strongly warranted to improve the survival of these patients. No significant financial relationships to disclose.