The problem is that levels of a single telltale protein can differ from case to case, making an assay based on one protein inherently unreliable. Sidransky says that Liebers method of measuring multiple biomarkers simultaneously has the potential to “diagnose the vast majority of people very accurately.”
In fact, according to Lieber, the “biggest advantage” of the nanowire detectors is that they could detect “10 or 100 things in parallel” without adding cost to the test.
Another benefit of the nanowire system is its flexibility. As new cancer markers are found, Lieber says, they could easily be incorporated into the device: “We could immediately take this new species and add that to our existing sensor.”
In talks with Lieber, oncologists have also suggested another application. Because the device gives results in real time, it could be used to monitor the effectiveness of cancer treatments. Right now, Lieber explains, the amount of drug a patient depends on his or her weight. Yet each person responds differently to different treatments. With such a nano-device, though, one could “fine-tune the dosage to make treatment much more effective.”
Lieber and his research group have already tested the ability of the device to detect cancer markers in human blood – a challenging task, since the target protein has a concentration around 100 billion times lower than the background proteins in serum. And they have also addressed some engineering issues with maintaining reliability.
How soon a cancer-detecting nano-device will be available depends, to a large extent, on developing the technology for mass production, according to Lieber, rather than with overcoming basic science obstacles. “If its sufficiently cheap, then people can get these tests on a periodic basis and see if theyre developing cancer. It could be ultimately like a CVS [pharmacy] test or a pregnancy test.”