Safety and Feasibility of Cryoablation during Immunotherapy in Patients with Metastatic Soft Tissue Sarcoma

Patients with metastatic soft tissue sarcoma (STS) undergo a wide array of treatments, including surgery, radiation, chemotherapy, immunotherapy, and ablative therapies, to control their disease. The combination of cryoablation and immunotherapy may lead to an enhanced antitumor immune response via the abscopal effect. It is hypothesized that the combination of cryoablation and immunotherapy in patients with metastatic STS is safe and feasible.A single-center retrospective analysis was performed on patients with metastatic STS who underwent cryoablation. Sixteen patients were treated with 27 cryoablation procedures while receiving ipilimumab and nivolumab from April 2017 to July 2020. Response Evaluation Criteria in Solid Tumors, 1.1, were used to determine the outcomes of nontarget tumors. Progression-free survival (PFS) and overall survival (OS) were calculated from the date of the first cryoablation after initiating immunotherapy until progression or death.Thirty-four tumors were cryoablated, 23 of which were intentionally subtotal. The most common tumor subtype was liposarcoma (n = 4). Thirteen (81%) patients had previously demonstrated disease progression on multiple lines of chemotherapy. All tumors cryoablated with a complete intention demonstrated a complete response. Seven patients had a clinical benefit, including 1 with a complete response, 1 with a partial response, and 5 with stable disease. The median OS was 14.1 months, with a median PFS of 2.3 months (95% confidence interval, 1.8-14.3). Five patients had pneumothoraces after cryoablation, 2 of whom required chest tube placement. Eleven patients experienced adverse events related to immunotherapy, 10 of whom experienced grade 1 or 2.Cryoablation in patients with metastatic STS undergoing immunotherapy is feasible and safe.