title: Skull base chordoma and chondrosarcoma: influence of clinical and demographic factors on prognosis: a SEER analysis.
abstract: OBJECTIVE
  Chordomas and chondrosarcomas are rare skull base tumors, with similar radiographic and clinical presentations. We investigated factors influencing long-term survival in these 2 tumors using the Surveillance Epidemiology and End Results (SEER) database.
  
  
  METHODS
  Patients with chordoma (n = 416) and chondrosarcoma (n = 269) within the skull base from 1983 to 2009 were identified within the SEER database. Kaplan-Meier curves and Cox proportional hazards models were used to test associations with survival. t tests and χ(2) tests were used to compare groups.
  
  
  RESULTS
  Chordoma and chondrosarcoma patients were similar demographically. Survival at 5 years was 65% for chordomas and 81.8% (P < 0.0001) for chondrosarcomas and at 10 years was 32.3% and 49.5% (P = 0.004). Multivariate analysis demonstrated chordomas had a worse prognosis even when we controlled for age and tumor size (hazard ratio 3.0, 95% confidence interval 1.9-4.7, P < 0.0001). For chordomas, multivariate analysis demonstrated increasing age and tumor size were significantly associated with reduced survival. For chondrosarcomas, multivariate analysis demonstrated older age, earlier decade of diagnosis, and mesenchymal subtype were significantly associated with reduced survival. Postoperative radiation was given to 42% and 41% of patients with chordomas and chondrosarcomas, respectively. The addition of radiation did not improve survival.
  
  
  CONCLUSIONS
  Consistent with previous case series, skull base chordomas have significantly worse prognosis than chondrosarcomas. Patients in the SEER database had worse survival overall compared with existing case series for both chordomas and chondrosarcomas, suggesting selection bias in the existing literature.
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA. Electronic address: leif-erik.bohman@uphs.upenn.edu.
authors.forename: Leif-Erik
authors.initials: LE
authors.lastname: Bohman
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Koch
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Bailey
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Alonso-Basanta
authors.affiliation: Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: John Y K
authors.initials: JY
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery; D002813:Chondrosarcoma / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery; D002817:Chordoma / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019635:Neurosurgical Procedures / Q000401:mortality*; D011379:Prognosis; D016016:Proportional Hazards Models; D018426:SEER Program; D019292:Skull Base Neoplasms / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult
keywords: Chondrosarcoma; Chordoma; Outcomes; Prognosis; Skull base