title: Clinical Features and Prognostic Factors of Children and Adolescents with Clival Chordomas.
abstract: OBJECTIVE
  Chordomas in children and adolescents are rare, and minimal published information is available. Our aim was to research clinical features and prognostic factors associated with clival chordomas in younger patients.
  
  
  METHODS
  The study included 25 patients (10 males and 15 females). Average follow-up time was 42.95 months (range, 2-108 months). Kaplan-Meier analysis was used to determine overall survival (OS) and progression-free survival. Pearson correlation was used to perform correlation analysis. Immunohistochemistry was used to detect Ki-67, cytokeratin 8 (CK8), platelet-derived growth factor receptor-β, and brachyury expression levels.
  
  
  RESULTS
  Average age (± SD) of patients was 14.44 (3.44) years. Total resection was achieved in 5 cases, and nontotal resection was achieved in 20 cases. Average OS of patients with Karnofsky performance scale score ≥90 and patients in the total resection group was significantly longer compared with OS of patients with Karnofsky performance scale score <90 (P = 0.041) and patients in the nontotal resection group (P = 0.0497). Patients with lower Ki-67 expression levels had longer OS (P = 0.0207). Progression-free survival of patients with lower CK8 expression levels was significantly longer compared with patients with higher CK8 levels (P = 0.008). Expression levels of platelet-derived growth factor receptor-β were significantly correlated with expression levels of brachyury (P = 0.016).
  
  
  CONCLUSIONS
  In children and adolescents with clival chordomas, higher preoperative Karnofsky performance scale score, total resection, and lower levels of Ki-67 and CK8 expression are favorable prognostic factors. Platelet-derived growth factor receptor-β may play a role in tumorigenesis and epithelial-mesenchymal transition of clival chordomas.
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Bai
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Gao
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Mingxuan
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors.forename: Songbai
authors.initials: S
authors.lastname: Gui
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
authors.forename: Chuzhong
authors.initials: C
authors.lastname: Li
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, Beijing, China; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Beijing Institute for Brain Disorders, Brain Tumor Center, Beijing, China; China National Clinical Research Center for Neurological Diseases, Beijing, China. Electronic address: zyz2004520@yeah.net.
authors.forename: Yazhuo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D002648:Child; D002817:Chordoma / Q000000981:diagnostic imaging* / Q000601:surgery*; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D055815:Young Adult
keywords: Adolescent; Children; Chordoma; Prognosis; Skull base