Determinants of Survival in Skull Base Osteosarcoma: A National Cancer Database Study.

Abstract: Objective Osteosarcomas of the skull base are rare and aggressive tumors that are most commonly treated with primary surgical resection and adjuvant chemoradiation. Using the National Cancer Database (NCDB), we analyzed demographic and clinical prognosticators for overall survival (OS). Methods The NCDB was queried for cases of histologically confirmed skull base osteosarcoma treated between 2004 and 2015, excluding patients receiving palliation or having less than 1 month of follow-up. A total of 314 patients treated with either surgery alone (n = 82), surgery with adjuvant radiation therapy (n = 35), surgery with chemotherapy (n = 114), or trimodality therapy (n = 56) were identified. Chi-square test for categorical variables, Cox proportional hazards models, and Kaplan-Meier log-rank analysis were used to test associations with treatment, OS, and survival time. Results Of the studied demographic characteristics (age, sex, race, overall health) and socioeconomic factors (income and average regional education), none were associated with OS (none p 5 cm (p = 0.045) were associated with poorer OS. Conclusion Tumor histologic subtype, advanced tumor grade, and greater tumor size are predictors of worse OS in skull base osteosarcoma. No significant differences in OS were identified based on treatment modality, which warrants further investigation.