SIRPA and sarcoma: This study will focus on four macrophage surface receptors representing M2 macrophages: signal regulatory protein alpha (SIRPα), leukocyte immunoglobulin-like receptor B1 (LILRB1), CD163, and mannose receptor (Cluster of Differentiation 206, CD206); it is the first study to investigate the prognostic role of soluble macrophage markers in sarcoma patients.