A ‘cancer lab’ on a chip

Finding out you have cancer is bad enough, but to then have to go to hospital for a painful and invasive biopsy to try to identify the exact type of tumour can be deeply traumatic.

But that may soon be a thing of the past: new, cheap devices the size of a silicon chip could provide the same information from a simple urine test in the doctor’s surgery, say the authors of a new review of microfluidic devices. 

Better yet, these tiny devices, based on networks of fluid channels thinner than human hairs, have the potential to distinguish between different strains of the same cancer, enabling personalised treatment. 

“If you isolate some cells and expose them to drug candidates you can predict the response of the patient in advance,” says Ciprian Iliescu, a researcher at IMT-Bucharest in Romania and co-author of a paper in the journal Biomicrofluidics.

“Then you can track how the tumour is evolving in response to treatment.”

One of the biggest challenges treating cancer is its diversity. There are more than 100 known cancers, with each having its own biomarkers; for example, specific proteins, cells or even fragments of the tumour. 

Although the biomarkers may be only tiny traces in the blood, researchers around the world are developing myriad methods to sift through and identify the many different species.

The devices direct the bodily fluids into complex structures such as forked flow channels, pillars, spirals and pools to process them. 

Precise analysis of the biomarkers is carried out with specifically designed nanotechnology: surfaces lined with intricate shapes, or molecules that attract specific species. Other approaches employ electrical, magnetic or acoustic fields to help select the biomarker target, and even have smarts: in-built electronic circuits for data processing. 

A handful of devices are already on the market, such as CellSearch, which identifies tumour cells from colon, breast and prostate cancer in blood samples. However, Iliescu says many more will come online in the next few years.

“The technology is there, the methods are there, it’s a matter of optimising them,” he says

“We need more and more clinical tests to bring this technology to maturity.”

Because telltale signs of tumours end up in the bloodstream, Iliescu says a liquid biopsy can give insights to genomic state of all cancer in the body. 

The authors term this a “global molecular status of the patient”, which could give quick information about the status of the cancer and whether it has spread.  Then, because of the ease of obtaining a fluid sample, the success of treatment can be monitored easily, and tweaked for maximum effect.

Iliescu even sees the possibility of exposing biomarkers in the fluid sample to drugs to get an early indication of which ones will be the most effective.

“You can start the treatment faster,” he says.