Cells from the main site of a tumour can circulate around the body via the bloodstream, causing the disease to spread.

Now a new microfluidic chip has been developed by researchers in China that has the ability of rapidly and efficiently separating and capturing live tumour cells, (CTCs) from the blood of a patient, for possible use in cancer screenings and assessments for treatment. Instruments that are presently available for identifying CTCs in the blood of a patient are either too slow for clinical use or deliver unreliable information. Confusion can enter the picture when trying to identify the rare CTCs from the more common white cells and other healthy cells. 

The latest method has proved to be very efficient as it has the ability of trapping in excess of 90 per cent of the CTCs. A stage at which red blood cells are carefully lysed or broken apart has also partly contributed to a reduction in the overall processing time. A common difficulty that hinders the processing time in CTC filtering devices of a similar type is the inclination of blood to clog the system. This is  reduced by lysing the red blood cells. Because the density of CTCs in the blood is connected to the advancement of the disease and the patients’ level of survival, the facility of being able to calculate live, individual CTCs in the bloodstream can assist medical professionals in establishing how serious a cancer is. Biopsy techniques can also be enhanced by the new procedure, as a small amount of blood is withdrawn instead of the usual method of examining tissue from primary or metastatic tumours. 

As well as having the potential to upgrade screening tests, the research team believe that in the future, the technique may assist doctors in the control of CTC-induced metastasis, which can be more deadly than the initial tumour. According to Ray Han, a professor at Peking University in Beijing, because the chip is able to capture viable CTCs, it creates opportunities for the development of new and efficient cancer biomarkers. Researchers also have the chance to accomplish a technology that is capable of directly removing CTCs from the human bloodstream – a type of CTC dialysis.