Plasma c-erbB-2 levels in breast cancer patients: prognostic significance in predicting response to chemotherapy.
OBJECTIVE
To determine the significance of plasma c-erbB-2 levels to assess the extent of disease spread and to predict the response to chemotherapy in node-positive breast cancer patients.


METHODS
We determined plasma levels of c-erbB-2 in 79 stages II and III breast cancer patients who received cyclophosphamide, methotrexate, and flourouracil (CMF)/cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone (CMFVP) chemotherapy. All patients had a minimum follow-up of greater than 60 months or until disease recurrence. Plasma samples were obtained before and after chemotherapy. Plasma c-erbB-2 levels were quantified by enzyme-linked immunoassay. c-erbB-2 levels were analyzed in relation to the patients' axillary lymph node status, menopausal status, disease status, disease-free survival (DFS), and steroid receptor status of tumor.


RESULTS
Plasma c-erbB-2 levels varied widely in breast cancer patients. In general, when all patients were included in the analyses, plasma c-erbB-2 levels before chemotherapy correlated significantly with the number of positive axillary lymph nodes and with postchemotherapy c-erbB-2 levels. No association was observed between pre- or postchemotherapy c-erbB-2 levels and other variables (patients' age at diagnosis, receptor status of the tumor, or disease status). The prognostic significance of different factors (ie, nodal status [one to three v > three positive nodes], menopausal status [pre- v postmenopausal women], estrogen receptor [ER] status [ER+ v ER-], and pre- and postchemotherapy c-erbB-2 levels) in predicting DFS was determined in all study patients. Among the variables examined, nodal status was the strongest predictor of DFS in these patients. The second most significant prognostic marker was postchemotherapy c-erbB-2 level. Prechemotherapy c-erbB-2 levels showed prognostic significance for DFS in a subset of breast cancer patients (ie, patients with > three positive nodes). Patients with greater than three positive lymph nodes and those with greater than 100 fmol/mL of plasma c-erbB-2 levels before therapy had significantly shorter DFS than did those patients with 100 fmol/mL or less c-erbB-2 levels.


CONCLUSIONS
In breast cancer patients, determination of c-erbB-2 levels before therapy is an important biomarker to assess the extent of disease spread in the lymph nodes. Postchemotherapy c-erbB-2 levels are also a prognostic indicator for DFS in patients who receive chemotherapy. Finally, in a subgroup of patients with greater than three positive nodes, prechemotherapy c-erbB-2 levels are a prognostic marker for response of patients to standard chemotherapy.
Mehta
R R
RR
Department of Surgical Oncology and the Biostatistics Facility, University of Illinois at Chicago, 60612, USA. rrm@vic.edu
McDermott
J H
JH
Hieken
T J
TJ
Marler
K C
KC
Patel
M K
MK
Wild
L D
LD
Das Gupta
T K
TK
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D003520:Cyclophosphamide / Q000008:administration & dosage; D018572:Disease-Free Survival; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008207:Lymphatic Metastasis; D008727:Methotrexate / Q000008:administration & dosage; D008875:Middle Aged; D011237:Predictive Value of Tests; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood* / Q000187:drug effects; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
D014408:Biomarkers, Tumor; D003520:Cyclophosphamide; D005472:Fluorouracil; D008727:Methotrexate; D011241:Prednisone; D018719:Erb-b2 Receptor Tyrosine Kinases; D014750:Vincristine