AdnaTest LungCancer is a highly specific immunomagnetic cell selection system for enriching circulating tumor cells from peripheral blood which includes a highly sensitive RT-PCR for detecting lung cancer-associated mRNA markers. The specificity of the detection of AdnaTest LungCancer is 95%. Using tumor markers for lung cancer in spiking experiments, 30 tumor cells in 5 ml blood are detected at a recovery rate of 100% (Table below: AdnaTest LungCancer specificity and recovery).
AdnaTest LungCancer specificity and recovery
|
ALDH1 |
GA733-2 |
All |
Non-spiked healthy donor samples |
0/20 |
1/20 |
1/20 |
Specificity |
100% |
95% |
95% |
Spiked healthy donor samples |
20/20 |
19/20 |
20/20 |
Recovery |
100% |
95% |
100% |
In approximately 80% of all CTCs from lung cancer samples, EMT and tumor stem cell metabolism is observable. Analyzed CTCs were positive for at least one of the EMT markers: Twist1, Akt2 and PI3KCA. The AdnaTest LungCancer provides – in addition to anti-EpCam - antibodies against Her2 and EGFR, resulting in a strong increase of performance (see "Increased sensitivity in lung cancer"). To cover the aforementioned tumor markers, the AdnaTest LungCancer contains primer mixes for both the detection of EMT and lung cancer associated markers.
Findings with detection systems based solely on EpCam as capturing target reached only 15% positivity, whereas the AdnaTest CTC-Select uses anti-EpCam, anti-Her2 and anti-EGFR antibodies in combination. EpCam expression analysis enables differentiation of epithelial-like cells, EMT-like cells and cells with tumor stem cell characteristics.
Leukocyte reduction is critical to minimize leukocyte bias.
The detection of tumor stemness-related markers like ALDH1, or EMT-related markers like Twist1, Akt2 or PI3KCα requires a significantly higher purity to eliminate a bias from contaminating leukocytes. The AdnaWash Leukocyte Reducer is a special buffer developed to reduce the leukocyte content during CTC enrichment. Using a CD45 endpoint PCR assay clearly demonstrates that the number of leukocytes is dramatically reduced using AdnaWash in the cell capturing procedure instead of PBS (see “Leukocyte reduction using AdnaWash”).