DETECTION OF COLORECTAL CANCER CELLS IN PERIPHERAL BLOOD USING FERROFLUIDS

JOHN H. MARKS, M.D., ARTHUR WEISS, M.D., LEON TERSTAPPEN, M.D., Ph.D.;
Medical College of Pennsylvania and Hahnemann University;
Lankenau Hospital, Rosengarten Bldg. - 3 West, 100 Lancaster Avenue, Wynnewood, PA  19096

We postulate that the number of detectable peripheral cells vary in conjunction with colorectal cancer stage and treatment.  To evaluate this hypothesis, 44 patients with primary, recurrent or metastatic colorectal cancers and 27 controls were evaluated to determine the volume of peripheral tumor cells detectable.  Monoclonal antibody labeled Ferrofluids, specific for epithelial cell surface adhesion molecules, anticytokeratin 5, 6, 8, 18 and antimucin 1 were mixed with 10-20 ccs. of patient’s blood.  Immunomagnetic separation was utilized to separate cells of ectodermal origin from peripheral blood.  Multiparameter flow cytometry utilized fluorescently labeled CAM 5.2 monoclonal antibodies conjugated to phycoerythran and a nucleic acid dye to separate out RBCs, anti-cytokeratin to detect epithelial cells, and CD45 to exclude leukocytes.  Using this technique, the assay can detect as little as one epithelial cell per 2 ccs. of blood, or one per 10⁷ - 10⁸ nucleated cells.

                 Control   Metastatic    Colon      Rectum   Recurrent Colon

N                  27           15                15               8                    6

Mean number of Epithelial  2.6(0-14)   45.2(0-400)    15.5(0-216)  41.4(0-469)      7.6(1-17) Cells

Peripheral cells were significantly increased in patients with colon and rectal cancer over controls. This is a potentially powerful tool to monitor treatment efficacy and colorectal cancer status, however, the results are still preliminary and require additional study.

FEROFLUIDS