Outcomes and Patterns of Care in Adult Skull Base Chondrosarcoma Patients in the United States

Abstract

Background: Chondrosarcomas of the skull base are rare intracranial tumors of chondroid origin. The rarity of these lesions has made it difficult to form a consensus on optimal treatment regimens. The aim of this study was to provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with chondrosarcoma of the skull base.

Methods: Patients with diagnosis codes for chondrosarcoma of the skull base were queried from the National Cancer Database for the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization.

Results: A total of 718 patients with chondrosarcoma of the skull base were identified. Mean overall survival (OS) in these patients was 10.7 years. Older age and presence of metastases were associated with worsened OS. Of patients, 83.3% received surgical intervention, and both partial resection and radical resection were associated with significantly improved OS (P < 0.001). Neither radiotherapy nor chemotherapy improved OS; however, patients who received proton-based radiation and patients who received high-dose radiation (≥6000 cGy) had significantly improved OS compared with patients who received traditional radiation.

Conclusions: In the largest study to our knowledge of skull base chondrosarcoma to date, both partial resection and radical resection significantly improved OS, thus supporting the goal of maximal safe resection to preserve vital neurovascular structures without sacrificing outcome. In patients who received radiotherapy, proton-based modalities and high-dose radiation were associated with increased OS.

Keywords: Chondrosarcoma; Proton therapy; Radiation; Resection; Skull base; Surgery.