Adjuvant Radiation Therapy for Thoracic Soft Tissue Sarcomas: A Population-Based Analysis

Abstract

Background: The role of adjuvant radiation therapy (RT) in the management of thoracic soft tissue sarcomas (STSs) remains unclear. We aimed to study the characteristics of patients with thoracic STS who received RT after surgical resection and investigate the impact of RT on survival outcomes. Methods: We queried National Cancer Database to identify patients with surgically resected thoracic STS from 2004 to 2012. Factors associated with receiving adjuvant RT were identified. Analyses were performed to identify prognostic factors and compare overall survival (OS) in both unmatched and propensity score–matched cohorts. Results: Overall, 1215 patients were identified, of whom 557 (45.8%) received adjuvant RT. Tumor grade (odds ratio [OR], 2.87; 95% confidence interval [CI], 2.18-3.77), tumor size (OR, 1.82; 95% CI, 1.36-2.42), and tumor margins (OR, 1.97; 95% CI, 1.43-2.72) were found to be significant predictors of receiving RT. Mean OS of patients receiving RT in the unmatched cohort was 91 months vs 88 months for patients who did not (P = .556). When adjusted for all variables, adjuvant RT was found to be associated with improved survival (hazard ratio, 0.79; 95% CI, 0.61-0.96). Survival analysis of the matched cohort also demonstrated improved survival with adjuvant RT (120 months vs 100 months; P = .02). Subgroup analysis in both the unmatched and matched cohorts showed patients with high-grade tumors more likely to benefit from adjuvant RT. Conclusions: This population-based analysis is the largest dataset of primary thoracic STSs to date and suggests significant survival benefit associated with adjuvant RT. The improvement in OS was more notable in patients with high-grade tumors. Randomized prospective studies are warranted to further understand the benefit of RT in this group.