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

PURPOSE/OBJECTIVE 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 purpose of this study is to provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with chondrosarcoma of the skull base. MATERIALS/METHODS Patients with diagnosis codes for chondrosarcoma of the skull base were queried from the National Cancer Database (NCDB) during the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS 718 individuals were identified with chondrosarcoma of the skull base. The mean overall survival in these patients was 10.7 years. Increased age and presence of metastases were associated with worsened overall survival. 83.3% of patients received surgical intervention and both partial and radical resection were associated with significantly improved overall survival (P<0.001). Neither radiotherapy or chemotherapy administration improved overall survival; however, amongst patients who received radiation, those who received proton-based radiation as well as those receiving high-dose radiation (≥ 6000 cGy) had significantly improved overall survival compared to traditional radiation. CONCLUSION In the largest study of skull base chondrosarcoma to date, both partial and radical resection significantly improve overall survival in patients with skull base chondrosarcoma, thus supporting the goal of maximal safe resection to preserve vital neurovascular structures without sacrificing outcome. Amongst patients receiving radiotherapy, proton-based modalities and high-dose radiation were associated with increased overall survival.