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Background: LPS is one of the most common subtypes of soft tissue sarcoma STS . In this retrospective analysis, e describe the outcome and prognostic factors of advanced LPS in a tertiary referral center. Methods: We identified all patients pts ith inoperable or metastatic dedifferentiated LPS DDLPS , myxoid LPS MLPS or pleomorphic LPS PLPS diagnosed andor treated at the University Hospitals, Leuven Belgium beteen 2000-2014 using an institutional sarcoma database LECTOR . Atypical lipomatous tumors ere excluded. Prognostic factors ere analyzed using univariate log-rank test and multivariate Coxs proportional-hazard model analyses. Results: We identified 100 pts 67 DDLPS, 25 MLPS, 8 PLPS ith a median age at diagnosis of inoperable andor metastatic disease of 62.5 yrs range 18-89 , 58 male. Median OS from diagnosis of inoperable andor metastatic disease as 13.0 months range 0-148 . To thirds of pts received systemic therapy, most common first-line chemotherapeutics being doxorubicin n = 32 , doxorubicin + alkylator n = 16 and trabectedin n = 5 . Best response upon first-line treatment as partialcomplete response PRCR , stable disease SD or progressive disease PD in 17 percent, 25 percent and 46 percent of pts, respectively. In the univariate analysis, significant prognostic factors for better OS ere a non-retroperitoneal primary tumor p lt 0.001 , undergoing metastasectomy p = 0.01 , MLPS subtype p lt 0.001 and response PRCRSD upon first-line therapy p lt 0.001 . Treatment regimen did not influence OS. In the multivariate analysis, metastasectomy [p = 0.039; HR 0.34 0.20-0.59 ] and PRCRSD [p = 0.047; HR 0.29 CI 0.15-0.53 ] retained prognostic significance. Conclusions: Inoperable, metastatic LPS is an aggressive malignancy ith poor prognosis and response to chemotherapy. Our survival data are similar to those reported in recent randomized prospective trials in non-selected STS. The prognostic factors identified in this study support the basic concept of offering systemic chemotherapy and metastasectomy to responding patients, though the retrospective nature of the analysis does not allo to dra definitive conclusions.,J Clin Oncol 34, 2016 suppl; abstr e22521 ,Publication Only Sarcoma