title: Cytokine and growth factor responses after radiotherapy for localized ependymoma.
abstract: OBJECTIVE
  To determine the time course and clinical significance of cytokines and peptide growth factors in pediatric patients with ependymoma treated with postoperative radiotherapy (RT).
  
  
  METHODS
  We measured 15 cytokines and growth factors (fibroblast growth factor, epidermal growth factor, vascular endothelial growth factor [VEGF], interleukin [IL]-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, interferon-gamma, tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein-1, and macrophage inflammatory protein-alpha) from 30 patients before RT and 2 and 24 h, weekly for 6 weeks, and at 3, 6, 9, and 12 months after the initiation of RT. Two longitudinal models for the trend of log-transformed measurements were fitted, one during treatment and one through 12 months.
  
  
  RESULTS
  During RT, log IL-8 declined at a rate of -0.10389/wk (p = 0.0068). The rate of decline was greater (p = 0.028) for patients with an infratentorial tumor location. The decline in IL-8 after RT was significant when stratified by infratentorial tumor location (p = 0.0345) and more than one surgical procedure (p = 0.0272). During RT, the decline in log VEGF was significant when stratified by the presence of a ventriculoperitoneal shunt. After RT, the log VEGF declined significantly at a rate of -0.06207/mo. The decline was significant for males (p = 0.0222), supratentorial tumors (p = 0.0158), one surgical procedure (p = 0.0222), no ventriculoperitoneal shunt (p = 0.0005), and the absence of treatment failure (p = 0.0028).
  
  
  CONCLUSIONS
  The pro-inflammatory cytokine IL-8 declined significantly during RT and the decline differed according to tumor location. The angiogenesis factor VEGF declined significantly during the 12 months after RT. The decline was greater in males, those without a ventriculoperitoneal shunt, and in those with favorable disease factors, including one surgical procedure, supratentorial tumor location, and tumor control.
authors.affiliation: Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Merchant
authors.forename: Chenghong
authors.initials: C
authors.lastname: Li
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xiong
authors.forename: M Waleed
authors.initials: MW
authors.lastname: Gaber
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000378:metabolism*; D004806:Ependymoma / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D006801:Humans; D007223:Infant; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D020266:Radiotherapy, Conformal; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; D009363:Neoplasm Proteins; D042461:Vascular Endothelial Growth Factor A