Kinetics of HER2/neu ECD in 45 patients treated with trastuzumab (Herceptin) between January 2001 and June 2005 at the Grenoble University Hospital.
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.
Gauchez
Anne-Sophie
AS
Biology Department, Grenoble University Hospital 38043 Grenoble cedex 9, France. ASGauchez@chu-grenoble.fr
Colonna
Marc
M
Brand
François-Xavier
FX
Ravanel
Nadia
N
Pasquier
Dominique
D
Payan
Raoul
R
Mousseau
Mireille
M
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
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab