Prognostic Factors and Survival Outcome in Patients with Chordoma in the United States: A Population-Based Analysis.

OBJECTIVE: To evaluate prognostic factors of patients with chordoma through a population-based analysis.

METHODS: Surveillance, Epidemiology, and End Results (SEER) database was queried for patients with chordoma from 1973 to 2013. Kaplan-Meier univariate analysis and Cox regression multivariate analysis were performed to examine prognostic factors in overall survival (OS) and disease-specific survival (DSS).

RESULTS: One thousand five hundred ninety-eight patients with chordoma are identified. Kaplan-Meier analysis showed that OS and DSS were 61% and 71% at 5 years and 41% and 57% at 10 years. Multivariate Cox regression analysis demonstrated that independent predictors of OS and DSS are age at diagnosis (hazard ratio [HR]= 2.80 [95% confidence interval {CI}, 2.12-3.70], P < 0.001; HR = 1.60 [95% CI, 1.18-2.16], P = 0.002), surgical treatment (HR = 0.62 [95% CI, 0.52-0.73], P < 0.001; HR = 0.64 [95% CI, 0.52-0.79], P < 0.001), radiation therapy (HR = 1.23 [95% CI, 1.07-1.42], P = 0.004; HR = 1.29 [95% CI, 1.09-1.54], P = 0.004), tumor size (HR = 1.53 [95% CI, 1.32-1.78], P < 0.001; HR = 1.62 [95% CI, 1.35-1.94], P < 0.001) and distant metastasis (HR = 3.40 [95% CI, 2.45-4.71], P < 0.001; HR = 3.77 [95% CI, 2.61-5.45], P < 0.001).

CONCLUSION: We report the largest study to date to evaluate prognostic factors of patients with chordoma. Multivariate analysis demonstrated that older age, greater tumor size, and distant metastasis were correlated with decreased survival, whereas surgical resection was correlated with increased survival. Patients receiving radiation therapy also showed decreased survival, likely an indication of the patients' advanced stage of disease, making them poor surgical candidates.