A monoclonal antibody cocktail for detection of micrometastatic tumor cells in the bone marrow of breast cancer patients.
We investigated whether monoclonal antibodies (MoAbs) reactive against both acidic and basic cytokeratins alone were sufficient to detect minimal numbers of contaminating epithelial tumor cells in the bone marrow of breast cancer patients. Monoclonal anti-cytokeratin antibodies (AE1 and AE3) were used to stain 14 breast carcinomas by the avidin-biotin-peroxidase technique. Nine tumors (64.3%) showed high reactivity and five (35.7%) showed low or moderate reactivity. Nine MoAbs that proved to be unreactive to light density bone marrow cells by immunoalkaline phosphatase histochemistry were screened for reactivity to breast carcinomas having only low or moderate positivity to cytokeratin antibodies. Three of nine MoAbs showed high percentages of positivity and were selected to supplement the anti-cytokeratin antibodies for immunohistochemical detection of minimal marrow disease in breast cancer patients. A MoAb cocktail was prepared, further tested for reactivity to another five breast carcinomas, and compared with cytokeratin staining alone. The cocktail labeled 100% of carcinoma cells in all the examined specimens. To determine the sensitivity of this panel for detecting minimal numbers of contaminating tumor cells in bone marrow, in vitro mixing experiments were performed. T47D breast carcinoma cells were mixed with bone marrow mononuclear cells at ratios from one tumor cell per 10 bone marrow cells up to one tumor cell per 1 x 10(6) marrow cells, and cytospin preparations were subsequently stained with the MoAb cocktail by the immunoalkaline phosphatase method. Our approach could detect one tumor cell in 1 x 10(5) hematopoietic cells.
Taha
M
M
Department of Hematology, University of Texas M. D. Anderson Cancer Center, Houston 77030.
Ordoñez
N G
NG
Kulkarni
S
S
Owen
M
M
Ro
J S
JS
Hortobagyi
G
G
Reading
C L
CL
Dicke
K A
KA
Spitzer
G
G
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000556:secondary; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000276:immunology
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D007633:Keratins