Maintrac liquid biopsy allows quantitative detection of circulating tumor cells without fixation, isolation, or enrichment. It uses fluorochrome-labeled antibody targeting EpCAM antigen on circulating tumor cells. In contrast, Cellsearch uses fixation and enrichment procedures that lead to loss of cells and antigenicity, resulting in dead cells. Comparison of the two methods using the same blood sample from a patient showed Maintrac detected more total events and circulating tumor cells than Cellsearch. Other CTC detection technologies have limitations such as relying too heavily on EpCAM expression or assuming CTCs are larger than blood cells. Cell-free tumor DNA analysis has problems like representing destroyed cells and additional mutations from DNA degradation.

1. Maintrac®
Maintrac liquid biopsy
cell staining allows
quantitative detection
of vital circulating
tumor cells
NO fixation.
NO isolation.
NO enrichment.
Fluorochrome
labeled antibody
FITC
Circulating
tumor cell
Surface
antigen
EpCAM

2. Cellsearch®
Fixation and enrichment
procedures leads to
LOSS of cells
LOSS of antigenicity.
Cells are DEAD
Magnetic beads –
(cells with low
EpCAM expression
can not be cought
by magnet)
Circulating
tumor cell
(dead cell
due to
fixation)
Fixation -
(destroys part of
surface antigens,
including EpCAM)

3. Comparison Maintrac vs CellSave
y = 0,1898x - 450,44
R
2
= 0,9191
0
500
1000
1500
2000
2500
3000
0 2000 4000 6000 8000 10000 12000 14000 16000
total events Maintrac
totaleventsCellSave

4. Duplicate analysis in
one patient, one blood sample
Maintrac®
results
Cellsearch
results

5. Cellsearch results
S poor and good prognosis
derived from the same blood sample
from the same patient
at the same time
...

6. Comparison
WebmedCentral CANCER
2011;2(2):WMC001490
Comparing Sequential Steps
For Detection Of Circulating
Tumor Cells: More Specific
Or Just Less Sensitive?

7. Other CTC technologies
Technique Problems
Magnetic beat enrichment Is EpCam expression sufficent for
enrichment?
Microfiltration Are all circulating tumor cells larger
than blood cells?
Negative Depletion Are all circulating tumor cells CD45
negative?
Adhesion to micropoles Technical problems?

8. CETC comparison to ctDNA
Technique Problems
Isolation from plasma DNA derived from destroyed cells.
Chemosensitivity on vital cells not
possible.
Derived from dead cells Stability of tumor DNA
Mutation analysis Additional mutations due to DNA
degradation