Myxoid Liposarcomas: Systemic Treatment Options

Myxoid/round-cell liposarcoma (MRCL) account for 30% of liposarcomas and are the most chemo-sensitive subtype of liposarcoma. The 5-year local relapse and distant metastasis rates are 10% and 20%, respectively. In the advanced setting, the first-line median progression-free survival and overall survival is 9 and 30 months, respectively. The overall response rate (ORR) by RECIST with anthracycline-based chemotherapy is around 40% and with trabectedin is 20%, although response is higher when captured by CHOI criteria. Anthracycline-based combination chemotherapy regimens remain the standard of care first-line treatment option. However, trabectedin is also effective and may be considered in the first-line setting when anthracyclines cannot be prescribed. Beyond chemotherapy, new therapeutic classes are being developed, including autologous adoptive modified T cell receptor cellular therapies which have shown promising results thus far. These new therapies utilize the immunogenic potential of cancer testis antigens, NY-ESO-1 and MAGE-A4, which are expressed in the vast majority of MRCL. Early phase trials have shown encouraging results with up to 40% ORR and a median progression-free survival up to 8.7 months. Other innovative strategies are being developed, tailored to the molecular biology of MRCL. This review summarizes current evidence for the use of standard chemotherapy and the new biomarker-selected treatments under development.