Correlation of circulating tumor cells with tumor size and metastatic load in a spontaneous lung metastasis model.
BACKGROUND
The prognostic value of circulating tumor cells remains unclear since, in principle, most tumor cells are unable to survive in the bloodstream. The aim of the study was to establish a system that can be used to investigate the metastatic process in more detail, with emphasis on circulating tumor cells.


METHODS
Human colon carcinoma cells (HT29) were transplanted into severe-combined-immunodeficient (scid) mice. The metastatic load in the blood was investigated using the human-specific carcinoembryonic antigen (CEA) as target for quantitative polymerase-chain-reaction (PCR).


RESULTS
A close correlation between the weight of the primary tumor and the number of circulating tumor cells was detected (r=0.7240; p<0.0001). Moreover, the number of circulating tumor cells and the actual number of spontaneous lung metastases was related (r=0.8283; p<0.0001).


CONCLUSIONS
A tumor xenotransplantation model is presented that allows for a detailed investigation of the metastatic process in three different compartments: the primary tumor bed, the bloodstream and the target organ of metastatic residency.
Katoh
M
M
Institute for Anatomy, Experimental Morphology, University Hospital Hamburg-Eppendorf Martinistr. 52, D-20246 Hamburg, Germany.
Neumaier
M
M
Nezam
R
R
Izbicki
J R
JR
Schumacher
U
U
D000818:Animals; D019073:HT29 Cells; D006801:Humans; D020014:K562 Cells; D008175:Lung Neoplasms / Q000097:blood / Q000556:secondary*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D009360:Neoplastic Cells, Circulating / Q000473:pathology*