Impact of Metastasectomy and Aggressive Local Therapy in Newly Diagnosed Metastatic Soft Tissue Sarcoma: An Analysis of the NCDB.

BACKGROUND The optimal management of patients with stage IV soft tissue sarcoma of the extremity (STSE) with distant metastases at diagnosis is unclear due to limited evidence and heterogeneity of current practice patterns. National guidelines have recommended surgical management of the primary site (SP) with or without radiotherapy (R), chemotherapy (C), and metastasectomy (M). METHODS In the National Cancer Database (NCDB), patients with initially metastatic STSE who received definitive SP from 2004 to 2014 were identified. Survival distributions were estimated and compared using the Kaplan-Meier method and log-rank tests, and covariates were compared using Chi-square tests or analysis of variance (ANOVA). Propensity score analysis using inverse probability of treatment weighting was used. RESULTS Overall, 1124 patients were included, with a median age of 55 years (range 18-90). Utilization of SP+M increased over time from 18.8% in 2004-2006, to 33.3% in 2007-2009, to 47.9% in 2010-2014 (p = 0.024). The addition of M to SP was associated with superior 5-year overall survival (OS) at 30.8% (SP+M+/-C+/-R) compared with 18.2% for those treated with non-surgical adjuvant therapies (SP+/-C+/-R) and 12.6% for SP alone (p < 0.0001). Positive surgical margins were noted in 24.1% of patients and was associated with worse OS (hazard ratio 1.44, p < 0.001) on multivariable analysis. CONCLUSIONS This is the first known study utilizing a large database to explore practice patterns and outcomes for patients with metastatic STSE receiving definitive SP. Utilization of metastasectomy increased in the study period and was associated with longer survival compared with SP alone. These hypothesis-generating data warrant additional study.