NY-ESO-1 is a ubiquitous immunotherapeutic target antigen for patients with myxoid/round cell liposarcoma.

BACKGROUND: Myxoid/round cell liposarcoma (MRCL) is the second most common liposarcoma subtype, accounting for >33% of liposarcomas and approximately 10% of all soft tissue sarcomas. Although MRCL is a chemosensitive subtype, patients with metastatic disease have a poor outcome. NY-ESO-1 is a cancer-testis antigen (also known as cancer germ cell antigen) that has been successfully targeted in vaccine trials and in adoptive T-cell therapy trials for the treatment of several solid tumors.

METHODS: The authors investigated the feasibility of targeting NY-ESO-1 in patients with MRCL by evaluating the prevalence of NY-ESO-1 expression in tumors using immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction analysis. NY-ESO-1-specific tumor recognition by NY-ESO-1-specific T-cells also was analyzed using a chromium release assay.

RESULTS: A search of the University of Washington Sarcoma Tissue Bank identified paraffin-embedded tumor samples from 25 patients with MRCL. NY-ESO-1 expression was observed in every MRCL tumor assessed (100%); in 18 tumors (72%), staining was homogenous. In all but 2 tumors, staining was sufficiently robust (2+) that such patients would be eligible for clinical trials of NY-ESO-1-directed therapy. By using NY-ESO-1 specific, CD8-positive T-cells, the in vitro sensitivity of myxoid liposarcoma cell lines to antigen-specific lysis was demonstrated.

CONCLUSIONS: The current results establish NY-ESO-1 as an important target antigen for the treatment of patients with MRCL.