title: Kinetics of HER2/neu ECD in 45 patients treated with trastuzumab (Herceptin) between January 2001 and June 2005 at the Grenoble University Hospital.
abstract: The aim of this study was to evaluate the utility of HER2/neu ECD concentration as a marker of the efficacity of clinical response to Herceptin.
  
  
  METHODS
  Iterative measurements of HER2/neu ECD (ELISA c-erbB2/c-neu Rapid Format Elisa kit QIA10 Calbiochem) concentrations in 45 patients treated with Herceptin between January 2001 and June 2005 at the Grenoble University Hospital.
  
  
  RESULTS
  Changes in HER2/neu ECD concentrations were observed in 21 patients (47%). The baseline concentration was the concentration of circulating HER2/neu ECD before treatment with Herceptin. In 15 patients, the mean baseline concentration was 52 ng mL(-1) (extreme values 13-170), which normalized no later than at the time of the 3rd administration of Herceptin. Nine patients (60%) were still alive 5 years later (p<0.05). For 6 patients, the mean baseline concentration was 800 ng mL(-1) (extreme values 140-2000) which persisted and even increased during Herceptin therapy; fewer than 25% were alive 30 months later (p<0.05). In the case of the 24 patients whose HER2/neu ECD concentration remained <5 ng mL(-1), survival time was intermediate.
  
  
  CONCLUSIONS
  The study confirmed the utility of HER2/neu ECD in predicting therapeutic response. However, as in the case of other circulating tumor markers, it is only useful when there is a variation in concentration. This marker should now be evaluated in multi-center studies covering a large number of homogeneous subjects.
authors.affiliation: Biology Department, Grenoble University Hospital 38043 Grenoble cedex 9, France. ASGauchez@chu-grenoble.fr
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Gauchez
authors.forename: Marc
authors.initials: M
authors.lastname: Colonna
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Brand
authors.forename: Nadia
authors.initials: N
authors.lastname: Ravanel
authors.forename: Dominique
authors.initials: D
authors.lastname: Pasquier
authors.forename: Raoul
authors.initials: R
authors.lastname: Payan
authors.forename: Mireille
authors.initials: M
authors.lastname: Mousseau
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018734:Genes, erbB-2; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D013548:Sweden; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab