Population-based survival analysis of primary spinal chordoma in the US from 2000 to 2020.

Purpose: Chordomas are rare malignant tumors that occur primarily in the axial skeleton. We seek to analyze trends affecting five-year overall survival (5y OS) among patients with primary spinal chordomas (PSC) of the vertebrae and sacrum/pelvis.

Methods: The Surveillance, Epidemiology, and End Results (SEER) Program was used to identify patients with PSC (ICD-O-3 histology codes 9370/3, 9371/3, and 9372/3) of the spine or sacrum/pelvis. Multivariate and univariate survival analyses were conducted to assess demographic, disease, or treatment characteristic trends.

Results: Eight-hundred-ninety-six patients diagnosed with PSC were identified. Patients 0-54 years at diagnosis had improved 5y OS compared to those either 55-69 years (HR = 1.78; p = 0.046) or those between 70 and 85 + years (HR = 3.92; p < 0.001). Histology impacted 5y OS: Cox regression demonstrated variance among the three histologies assessed (p < 0.001), while univariate analysis demonstrated patients with dedifferentiated chordoma (1.0% of cohort; 33.3% [1.9,64.7]) and chondroid chordoma (2.0% of cohort; 52.5% [26.1,78.9]) had decreased 5y OS compared to those with general chordoma (72.2% [68.8,75.6]; p < 0.001). Nonmarried patients had decreased 5y OS on univariate analysis (65.2% [59.4,71.0] versus 76.2% [72.0,80.4]), with widowed patients being the primary driver of this on subanalysis. Treatment with gross total resection was associated with increased 5y OS (HR = 0.22, p < 0.001), as was treatment with radiotherapy (HR = 0.69, p = 0.030).

Conclusion: Patient age and marital status were significant demographic factors associated with changes in 5y OS among those with PSC. PSC histology is a potentially important prognostic factor in the management of disease.