Adjuvant radiation for positive margins in adult head and neck sarcomas is associated with improved survival: Analysis of the National Cancer Database.

Abstract

Adult head and neck (H&N) sarcomas are a rare malignancy with limited data delineating the role of postoperative radiotherapy (PORT), particularly for a positive surgical margin. There are no randomized trials supporting the use of PORT, therefore treatment trends vary between institutions. A positive margin predicts recurrence and poor survival outcomes. This study uses the National Cancer Database (NCDB) to investigate whether PORT improves overall survival (OS) in adult H&N sarcomas with a positive margin and how utilization has changed. Patients (n = 1142) in the NCDB from 2004-2013 with adult H&N sarcomas who underwent resection and had a positive margin. Factors significantly associated with increased utilization of PORT were: having insurance, salivary gland primary site, high-risk histology, poor differentiation, and a macroscopic positive margin. Treatment with PORT was associated with improved 5-year OS for all patients with a positive margin (57% vs 48%; P = .002), both microscopic (57% vs 49%; P = .010) and macroscopic (57% vs 41%; P = .036). Improved OS was significant after controlling for other known covariates on multivariate analysis (HR: 0.76; [0.64-0.90]; P = .002). Treatment at a community-based facility was an independent predictor for reduced OS (HR: 1.37; [1.15-1.64]; P < .001). The percentage utilization (53%) of PORT for these patients did not change significantly over time. PORT provides a significant survival benefit for adult H&N sarcoma patients with either a microscopic or macroscopic positive margin; however, PORT is underutilized. Treatment at academic/research cancer programs was associated with increased utilization of PORT and improved survival outcomes.