Longitudinal changes in serum HER-2/neu oncoprotein levels in trastuzumab-treated metastatic breast cancer patients.
BACKGROUND
To evaluate longitudinal variations of serum HER-2/neu extracellular domain (sHER-2) in metastatic breast cancer patients receiving combined trastuzumab treatment.


METHODS
Thirty-three patients were monitored by serial sHER-2 ELISA (Oncogene Science). Results were compared to time to progression (TTP) and survival from treatment initiation. Non parametric statistical tests were used.


RESULTS
Median sHER-2 before first injection was 41.37 ng/ml (range 7.54-1597.00 ng/ml, n=32). Mean sHER-2 levels differed significantly between responders (n=20) and non responders (n=13) (p<0.0001). Median TTP (266 days, range 35-1000 days) was unrelated to clinico-biological variables at diagnosis or number and site of metastases before treatment. Patients with pre-treatment sHER-2 levels < or = 30 ng/ml (n=14) had a significantly longer TTP than the group with sHER-2 > 30 ng/ml (n=18) (p=0.0346) and sHER-2 levels were of prognostic value for overall survival from first injection (p=0.0150).


CONCLUSIONS
Our results show that monitoring serum HER-2/neu levels during metastatic breast cancer can provide a real time assessment of a woman's HER-2/neu status and can provide important information for therapeutic decisions.
Bethune-Volters
Anne
A
Service d' Oncologie Médicale, Centre René Huguenin de Lutte Contre le Cancer, 35 rue Dailly, 92 210 Saint-Cloud, France.
Labroquere
Marc
M
Guepratte
Sylvie
S
Hacene
Kamel
K
Neumann
Rainer
R
Carney
Walter
W
Pichon
Marie-France
MF
D000328:Adult; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy*; D002272:Carcinoembryonic Antigen / Q000097:blood; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D002272:Carcinoembryonic Antigen; D018396:Mucin-1; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab