Metastasectomy Following Immunotherapy with Adoptive Cell Transfer for Patients with Advanced Melanoma

Background: Immunotherapeutic treatment strategies including adoptive cell transfer (ACT) for metastatic melanoma are capable of mediating complete and durable responses, as well as partial responses and prolonged disease stabilization. Unfortunately, many patients ultimately develop progressive disease. The role of salvage metastasectomy in managing these patients has not been evaluated. Methods: Records of patients with metastatic melanoma treated with ACT at a single institution between 2000 and 2014 were reviewed. Patients with an objective response by RECIST criteria or disease stabilization of at least 6 months and who subsequently developed progressive melanoma and were managed with metastasectomy as the next therapeutic strategy were studied for progression-free survival (PFS) and overall survival (OS). Five additional clinical parameters were also reviewed for association with outcomes. Results: Of 115 patients treated with ACT who met our response criteria and then developed progressive disease, 26 (23%) had surgery. There were no mortalities related to surgical intervention. Median follow-up after surgery was 62 months. Median PFS after surgery was 11 months and five-year OS was 57%. The development of a new site of metastasis after ACT was associated with poor PFS and OS. Conclusions: Surgery after immunotherapy is safe. Long PFS and OS can be achieved by metastasectomy in selected patients with progressive melanoma following treatment with ACT. Clinical variables important for patient selection for metastasectomy after immunotherapy remain largely undefined. Improvements in immunotherapeutic treatment strategies may increase the role of surgery for patients with advanced disease.