LAUSR

ABSTRACT Introduction: Epithelioid sarcoma (ES) is a rare malignancy of mesenchymal origin that accounts for <1% of soft tissue sarcomas. Research in ES has been limited by its rarity, and there are no standardized treatment recommendations. Areas covered: A PubMed search for the key terms including epithelioid sarcoma, chemotherapy, systemic therapy and abstracts were reviewed for reports on chemotherapy treatment and outcomes in ES. There were no prospective trials limited to ES. Available data included case reports, single-institution retrospective series, and multi-institutional retrospective analyses. Small, retrospective series have identified a role for palliative chemotherapy, though overall outcomes remain poor for patients with metastatic disease. Over 90% of tumors are known to exhibit loss of Integrase Interactor 1 (INI1), and there is emerging interest in utilizing this as a potential therapeutic target. Additional signaling pathways including mammalian target of rapamycin (mTOR) and epidermal growth factor (EGF) have been implicated in the pathogenesis of ES. Expert opinion: Given the limited efficacy of traditional cytotoxic agents, the development of novel treatment strategies is an area of unmet need. As the understanding of the pathogenic mechanisms in epithelioid sarcoma improves, targeting of critical pathways may produce promising treatments in the future.