CTC Methods in comparison
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.
CTC Methods in comparison
- 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