Impact of surgical resection on survival in patients with metastatic soft tissue sarcoma and comparison between synchronous and metachronous metastases

Background: The role of local surgery in patients with metastatic soft tissue sarcoma (STS) remains unknown. The study aims to assess the clinical outcomes and impact of surgical resection on survival in patients with metastatic STS and elucidate the survival differences between synchronous and metachronous metastatic groups. Methods: Among the 272 patients with STS treated between 2000 and 2018, 84 with synchronous or metachronous metastasis were included. Associations between overall survival and primary tumor resection and metastasectomy were assessed using multivariate Cox regression analyses to adjust for baseline differences between surgically and non-surgically treated patients. Propensity score matching was applied to compare synchronous and metachronous metastasis. Results: Among the 84 patients included, 69 (82%) and 41 (49%) underwent primary tumor resection and metastasectomy, respectively. The 2- and 5-year overall survivals of all patients after first detection of metastasis were 51.1% and 24.4%, respectively. Multivariate analysis showed that size <8 cm, grade <3, and number of metastases <4 were associated with longer overall survival. After adjusting for baseline demographic and tumor characteristics, primary tumor resection and metastasectomy still had favorable effects on survival. Tumor subtypes, grade, and number of metastases differed significantly between synchronous and metachronous groups. However, after adjusting for these valuables, both groups exhibited comparable survival. Conclusions: Approximately one fourth of the patients with metastatic STS survived for >5 years. Our results showed that surgical resection of primary tumors or metastatic lesions had favorable impact on survival even after adjusting for patient backgrounds, with comparable survival observed between those with synchronous and metachronous metastases. (C) 2021 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.