Treating and diagnosing different types of cancer is a difficult and arduous process that requires many invasive procedures. Since early identification of cancer and close monitoring of response to cancer treatments is vital to the survival of the patient, lots of research is being conducted into better ways to diagnose cancer.

Medical researchers from the Massachusetts General Hospital (MGH) Biomicroelectromechanical Systems (BioMEMS) have developed a new method of sampling circulating tumor cells (CTCs) from blood. The problem in the past with sampling these cells is that CTCs are rare in the blood stream and very fragile. Previous methods of analyzing CTCs require pre-processing of large blood samples, which often damaged the CTCs needed for testing.

The researchers have developed a new device called the CTC-chip intended to allow for sampling of the CTCs easily from the blood. Previous microchip based systems for measuring CTCs were only used with samples of blood from fingerpicks like diabetics use for testing blood glucose with a glucometer. Detecting CTCs in quantities useful to doctors required blood samples 1,000 to 10,000 times larger.

One of the researchers, Dr. Daniel Haber, MD, said, “This use of nanofluidics to find such rare cells is revolutionary, the first application of this technology to a broad, clinically important problem. While much work remains to be done, this approach raises the possibility of rapidly and noninvasively monitoring tumor response to treatment, allowing changes if the treatment is not effective, and the potential of early detection screening in people at increased risk for cancer.”

The CTC-chip is described as a business card sized silicon chip covered with 80,000 microscopic posts coated with an antibody to a protein expressed on most solid tumors. In trials, researchers say that the chip was able to detect CTCs from 116 tested blood samples from cancer patients with a 99% success rate. At the same time, the chip was tested with volunteers that were cancer free and no CTCs were found.

The chips is sensitive enough according to researchers to be able to use it for real time monitoring of the effectiveness of cancer treatments in patients and to look for potential drugs that the cancer will be susceptible to.

Mehmet Toner PhD and senior author of the report on the CTC-chip in the December 20 issue of Nature explains the process of using the CTC-chip, “We developed a counterintuitive approach, using a tiny chip with critical geometric features smaller than a human hair to process large volumes of blood in a very gentle and uniform manner – almost like putting a ‘hose’ through a microchip.”