Trends in the use of immunotherapy to treat soft tissue sarcoma

Background: The role of immune-oncology (IO) therapy in soft tissue sarcoma (STS) is underexplored. This study characterized IO use in STS. Methods: This is a retrospective analysis of patients with a soft tissue mass in the National Cancer Database, 2011-2021. Patients were categorized by IO receipt status. Groupwise testing and proportional trend tests were performed with Chi-squared tests. Multivariate logistic regression was performed to assess factors associated with IO receipt. Results: Of the 103,092 patients with STS, 1935 (1.9 %) received or were recommended IO therapy. IO use increased 10-fold (0.24 %-2.5 % from 2011 to 2021; p < 0.0001). Patients had higher odds of receiving IO when having higher grade tumors and metastatic disease, and when treated at an academic research center (all p < 0.001). Conclusions: IO use in STS is low but increasing and primarily used in the metastatic setting. Future studies should identify biomarkers of IO response and facilitators for treatment receipt.