CTCs are cells shed from the primary tumor into the bloodstream; they are the carriers of the metastatic process. Of every billion tumor cells, only a few million CTCs enter the blood per day — detecting and characterizing these rare cells requires advanced technologies.
Why Do CTCs Matter?
- Metastasis mechanism: CTCs are the "seeds" of metastasis — understanding which organs they travel to shapes the treatment strategy
- Treatment response: changes in CTC counts can precede imaging evidence of response
- Resistance mechanisms: genetic/protein changes in CTCs can reveal acquired resistance mechanisms
- Non-invasive repetition: longitudinal data through blood draws instead of surgical biopsy
Challenges in CTC Detection
- ~1–10 CTCs per mL of blood (among millions of leukocytes) → rare-event analysis
- CTCs with low EpCAM expression (having undergone EMT) may escape EpCAM-based capture
- Blood processing is time-sensitive; delays cause CTC loss
CTC Detection by Flow Cytometry
With a multicolor flow cytometry panel, CTCs are identified by combining CD45 (leukocyte negative selection), cytokeratin (CK, epithelial marker), EpCAM and DAPI (nuclear staining). Spike-in controls establish the LOD and recovery rates.
Our CTC analysis services are detailed on the contact page.
Rx-only——処方箋制のスクリーニング検査. Galleri® は診断検査ではありません。陽性結果は癌の診断を意味せず、陰性結果は癌を除外するものではありません。本検査は、医師が推奨する定期的な癌スクリーニングの代わりになるものではありません。 Galleri® はすべての癌種を検出するものではありません。