title: Non-invasive methods of assessing angiogenesis and their value in predicting response to treatment in colorectal cancer.
abstract: BACKGROUND
  Tumour neoangiogenesis can be assessed non-invasively by measuring angiogenic cytokine concentrations in peripheral circulation and by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The aim of this study was to assess whether these methods can predict and monitor response to treatment in patients with rectal cancer treated with preoperative chemoradiotherapy.
  
  
  METHODS
  Serum and plasma vascular endothelial growth factor levels were measured in 31 patients with T3/T4 rectal cancers before quantitating tumour permeability (ln Ktrans) by DCE-MRI. Sixteen patients receiving preoperative chemoradiotherapy had serial vascular endothelial growth factor (VEGF) and DCE-MRI measurements. Response to treatment was assessed using World Health Organization criteria.
  
  
  RESULTS
  Serum VEGF and ln Ktrans correlated before treatment (r = 0.48, P = 0.01). Responsive tumours (n = 8) had higher pretreatment permeability values than non-responsive tumours (n = 8) (mean ln Ktrans - 0.46 and - 0.72 respectively; P = 0.03). Compared with pretreatment values, responsive tumours showed a marked reduction in permeability at the end of treatment (mean ln Ktrans - 0.46 and - 0.86 respectively; P = 0.04). Pretreatment serum VEGF levels were not statistically different between the two groups.
  
  
  CONCLUSIONS
  Rectal tumours with higher permeability at presentation appear to respond better to chemoradiotherapy than those of lower permeability. This may allow preselection of appropriate tumours for these regimens, with patients with low-permeability tumours being considered for alternative therapies.
authors.affiliation: Department of Surgery, Mayday University Hospital, Thornton Heath, UK.
authors.forename: M L
authors.initials: ML
authors.lastname: George
authors.forename: A S
authors.initials: AS
authors.lastname: Dzik-Jurasz
authors.forename: A R
authors.initials: AR
authors.lastname: Padhani
authors.forename: G
authors.initials: G
authors.lastname: Brown
authors.forename: D M
authors.initials: DM
authors.lastname: Tait
authors.forename: S A
authors.initials: SA
authors.lastname: Eccles
authors.forename: R I
authors.initials: RI
authors.lastname: Swift
mesh_terms: D015179:Colorectal Neoplasms / Q000098:blood supply* / Q000188:drug therapy / Q000532:radiotherapy; D003131:Combined Modality Therapy; D016228:Endothelial Growth Factors / Q000097:blood; D005500:Follow-Up Studies; D006801:Humans; D008222:Lymphokines / Q000097:blood; D008279:Magnetic Resonance Imaging / Q000379:methods; D009389:Neovascularization, Pathologic / Q000097:blood / Q000175:diagnosis*; D012333:RNA, Messenger / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors