RecruitingProcedureCirculating Tumor DNA in Soft Tissue SarcomaThis research study will collect blood and tumor tissue samples from patients with soft tissue sarcoma to look at circulating tumor deoxyribonucleic acid (DNA). When tumor cells are damaged or die, DNA from the tumor cells are released into the blood stream as the cells break down. This is called circulating tumor DNA. Circulating tumor DNA is an important biomarker that may be used in cancer detection, prediction of treatment response, and disease monitoring.