Detection and clinical significance of circulating tumour cells in patients with colorectal carcinoma

Abstract

Circulating tumour cells (CTCs) are tumour cells identified in the peripheral blood of patients with malignant disease. CTCs present a very interesting biomarker with promising potential for use in the treatment management of patients with colorectal cancer. Unlike other tumour biomarkers, CTCs are living tumour cells that carry molecular and biological information about the tumour as a whole and reflect ongoing mutational changes.
Detection of CTCs from peripheral blood presents a simple and easily repeatable method of liquid biopsy. However, various techniques of CTC selection and detection render clinical use of CTC as a clinical biomarker difficult. The presence/amount of CTCs correlates very well with prognosis and patients´ survival. Since CTCs have metastatic potential, knowledge of the effect of different treatment modalities on the amount of CTCs in the blood appears to be very important. It can be expected that a more effective treatment regimen will be associated with a reduction in blood CTC levels, and also with a better prognosis. Conversely, an increase or persistence of CTC levels will be associated with resistance to the applied treatment.
Routine use of CTCs in clinical practice is limited predominantly by price and very high variability of available scientific evidence. Recently published studies demonstrated the promising potential of CTCs; however, further research will be required for their routine use in clinical practice.