(A522) Chordomas and Chondrosarcomas of the Skull Base: A SEER Database Analysis

Introduction: Chondrosarcomas and chordomas are rare tumors of the skull base, accounting for less than 1% of all skull base tumors. Both conditions pose challenges in diagnosis and treatment, and there is still a relative lack of objective guidelines for management. The aim of this study is to compare incidence, survival rates, and treatment strategies for patients with these two malignancies.

Methods: The Surveillance, Epidemiology, and End Results (SEER) database was queried for patients diagnosed with chordomas and chondrosarcomas of the skull base between 2000 and 2021. Chi-square analysis and t tests were used to compare demographics, incidence, treatment, and survival between the two groups.

Results: 798 patients with chondrosarcomas and 1330 patients with chordomas of the skull base were identified. The 5-year relative survival was 87.7% for chondrosarcomas and 81.9% for chordomas (p < 0.001), while the 10-year survival was 77.4% for chondrosarcomas and 66.0% for chordomas (p < 0.00001). 64% of chondrosarcoma patients and 69% of chordoma patients received surgery (p < 0.00001). 31% of chondrosarcoma patients and 41% of chordoma patients received some form of postoperative radiation (p < 0.001). The 10-year survival for chondrosarcoma and chordoma patients who received surgery without radiation was 81.6% and 68.4%, respectively, which is higher than the respective overall survival rates for both populations. This was not the case for patients who received radiation only, for which the survival rate was lower in both populations.

Conclusions: This is the largest analysis to date of patients with chondrosarcomas and chordomas of the skull base. Surgical resection continues to be a strong predictor of improved survival. Chordoma patients tend to receive surgical intervention and postoperative radiation at higher rates than chondrosarcoma patients. However, the overall survival is still lower for chordoma patients versus chondrosarcoma patients, regardless of treatment. More studies are needed to examine the effect of tumor size on surgical feasibility, as well as the specific impact of radiotherapy on survival.