Factors for Overall Survival in Patients with Skull Base Chordoma: A Retrospective Analysis of 225 Patients.

BACKGROUND Although a controversial and complex issue, the prognostic factors of skull base chordomas are worth exploring. METHODS Prognostic factors associated with overall survival (OS) were retrospectively estimated in an individual cohort of skull base chordomas prospectively maintained for 10 years by a Kaplan-Meier method and univariate Cox proportional hazards model. Multivariate analysis by Cox regression analysis was performed to identify the independent prognostic factors. A nomogram was then formulated by R software based on the results. RESULTS A total of 180 primary patients and 45 recurrent cases were included, with a mean follow-up period of 43.7 months (range, 4-127 months). The OS of the primary group at 5 years and 7 years was 84% and 78%, and the mean OS was 103.8 months, which was significantly longer than the recurrent group, in which the mean postrecurrent OS was 68.4 months. In the primary group, preoperative Karnofsky Performance Status (KPS) score (P = 0.004) and a decline of perioperative KPS score (P = 0.015) were identified as independent predictors of OS. A nomogram was contracted to predict 5-year, and 7-year OS, which was well calibrated and had good discriminative ability (adjusted Harrell C statistic, 0.74). In the recurrent group, visual deficit was verified as an independent risk factor associated with postrecurrent OS (P = 0.014). CONCLUSIONS Both pathologic and perioperative KPS score evaluations are significant in OS prediction of both primary and recurrent cases. The nomogram for primary lesions, consisting of preoperative functional status and its perioperative changes, appears useful for risk stratification of long-term survival.