A circulating tumor cell has sloughed off cancerous tissue and moves through the bloodstream to a new site.
Circulating Tumor Cells Assay
- CTC enumeration helps in determining the prognosis of a patient in metastatic breast, metastatic colon & metastatic prostate cancer. Falling CTCs after initiation of therapy indicates a better prognosis compared to where the counts are same or rising.
- CTC is checked at three time points –before initiation of therapy, after completion of first cycle & one year later.
- Defined threshold values for CTC counts for specified cancers such as Breast, Prostate, Colorectal cases, helps to assess disease status even at the baseline CTC count.
- CTCs can be isolated for further molecular characterization so that the behavior of the tumor can be assessed in real time and treatment can be planned accordingly.
- Early detection of CTC helps to take interventional measures.
Benefits over PET/CT scan
- CTC findings are available after the first cycle of chemotherapy or radiotherapy where as PET would take 2-3 months to show findings.
- Detection of malignancy is not masked by inflammation/infection /healing tissue
- Benign conditions are not misinterpreted as malignant
- No radiation risk due to radioactive material
- No restriction about tumor size