title: Circulating endothelial cells predict for response to bevacizumab-based chemotherapy in metastatic colorectal cancer.
abstract: OBJECTIVE
  Standardized enumeration of CEC counts is required to minimize variability and allow cross-studies comparisons. The purpose of this paper is to identify CEC threshold proposal, by CellSearch system, for determining response to bevacizumab-based chemotherapy in metastatic colorectal cancer.
  
  
  METHODS
  From July 2007 to June 2008, 33 patients treated with FOLFOX4 plus bevacizumab were enrolled in a prospective study. From January 2007 to June 2007, before bevacizumab was approved by the government in Japan, 31 patients treated with FOLFOX4 as a control were enrolled. CECs of whole blood at the baseline, day 4, 2 weeks after initiation of chemotherapy were isolated and counted using CellSearch system.
  
  
  RESULTS
  There was no correlation between CEC levels and the outcome in the FOLFOX4. In the bevacizumab-based chemotherapy, CEC levels at the baseline were significantly associated with the outcome. Patients with 65 or more CECs at the baseline had a shorter median PFS and OS, than the median PFS and OS of less than 65 CECs at the baseline in the bevacizumab-based chemotherapy (P = 0.003, P = 0.027, respectively). By univariate and multivariate Cox proportional-hazards regression, CEC levels (cut-off; 65) at the baseline indicated the strongest predictor for the outcome to bevacizumab-based chemotherapy.
  
  
  CONCLUSIONS
  A threshold of lower than 65 CECs, by the CellSearch System, at the baseline was a significant predictor of the outcome for colorectal cancer patients treated with bevacizumab-based chemotherapy.
authors.affiliation: Department of Medical Oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsusaka
authors.forename: Mitsukuni
authors.initials: M
authors.lastname: Suenaga
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mishima
authors.forename: Koichi
authors.initials: K
authors.lastname: Takagi
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Terui
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Mizunuma
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Hatake
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D000068258:Bevacizumab; D002452:Cell Count; D002469:Cell Separation; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D018572:Disease-Free Survival; D042783:Endothelial Cells / Q000502:physiology*; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D053208:Kaplan-Meier Estimate; D002955:Leucovorin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D009944:Organoplatinum Compounds; D000068258:Bevacizumab; D002955:Leucovorin; D005472:Fluorouracil