Omega Genetik

عام — أساسيات الخزعة السائلة

What Is a CTC (Circulating Tumor Cell)?

The rare cells that carry metastasis: clinical importance, detection challenges, and the flow cytometry identification approach.

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.

بوصفة طبية فقط — اختبار مسح. اختبار Galleri® ليس اختباراً تشخيصياً. النتيجة الإيجابية لا تعني تشخيص السرطان، والنتيجة السلبية لا تنفي وجوده. لا يُغني الاختبار عن فحوصات المسح الدورية التي يوصي بها طبيبك. لا يكتشف اختبار Galleri® جميع أنواع السرطان.

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