Outcomes and Practice Patterns for Aggressive Local Therapy in Newly Diagnosed Stage IV Soft Tissue Sarcoma: An NCDB Analysis

Abstract

Current practice patterns for patients with stage IV soft tissue sarcoma of the extremity (STSE) are not well described. Data is scarce, and the optimal management of patients with stage IV disease is unclear. Surgery to the primary site (SP) can be complemented by other modalities such as metastasectomy (M), chemotherapy (C), and radiotherapy (R). This study seeks to determine care patterns, the utilization of therapies in addition to SP, and their associated survival outcomes in the National Cancer Data Base (NCDB). In the NCDB, patients with stage IV STSE with complete treatment records who received definitive SP from 2004-2014 were identified. Survival distributions were estimated using the Kaplan-Meier method and compared using log-rank tests. Covariates were compared using chi-squared tests or ANOVA. A total of 1,291 patients met entry criteria. The median age of diagnosis was 55 (range 18-90). 279 patients (21.6%) received SP alone, 324 patients (25.1%) received SP+C, 209 patients (16.2%) received surgery and radiation to the primary site (SP+R), 287 patients (4.6%) received SP+M+C, 42 patients (3.3%) received SP+R+M, and 55 patients (4.3%) received SP+R+M+C. The utilization of SP+M increased over time increasing from 18.8% in 2004-2006, to 35.9% in 2007-2009, to 45.3% in 2010-2014 (p=0.005). 58.8% of patients received care at an academic center, and there was superior overall survival (OS) in this cohort compared to those treated at community cancer programs (HR 0.71 [95% CI: (0.57-0.89)], p=0.003) on multivariable analysis (MVA). 5-yr OS was 16.2% following SP alone compared to 31.4% for patients treated with metastasectomy (SP+M+/-C+/-R) and 20.7% for those treated with other non-surgical adjuvant therapies (SP+C, SP+R, SP+C+R) (p<0.0001). This is the first known study utilizing a large database to explore practice patterns for patients with stage IV STSE. Utilization of metastasectomy increased in the study period and was associated with longer survival compared to surgical resection of the primary tumor alone.