The promise of immunotherapy in the treatment of sarcoma: A state-of-the-art review of practice changing research and future directions

Soft-tissue sarcoma (STS) poses unique challenges to treatment due to its rarity and heterogeneity. Comprised of multiple histologies which, among other characteristics, differ in their genetic makeup, tumor microenvironment, recurrence patterns and therefore response to treatment, STS is treated primarily with surgical resection, with systemic therapy used in high-risk or metastatic cases. In the era of immunotherapy, STS has been characterized as predominantly immune-cold with few histologies demonstrating consistent robust responses to checkpoint inhibition in the metastatic setting. Strategies to improve checkpoint inhibition responsiveness, such as combination therapies and treatment in the neoadjuvant setting, have shown promise in certain sarcoma subtypes. Other immunotherapeutic approaches, such as adoptive cellular therapies, as well as development of reliable biomarkers for response to immune checkpoint inhibitors, are the subject of ongoing research in this field.