Scientists Develop New Method to Detect Early Cancer
Tiny chip analyzes blood for presence of protein biomarker (Nov. 2)
It may soon be possible to test a person for cancer with just a drop of blood and a small machine. European scientists have developed a device for detecting the HSP70 protein, which is over-expressed in patients with many types of cancer. The objective: to make a diagnosis extremely early in the disease process, thereby improving outcomes for patients.
HSP70, a protein indicating stress in the human body, is a biomarker for prostate, colon, esophagus, lung, and brain cancer. Being able to track this protein in patients — making early diagnoses of these types of cancer much more likely — would therefore be useful for physicians. Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) are developing a sensitive, easy-to-use HSP70 detection platform. The device, which will be no bigger than a small suitcase, is expected to be on the market in 2014.
The detection platform requires only a drop of the patient's blood. The blood is inserted into a 1-centimeter-square chip that contains layers of microchannels, which are no wider than a human hair. Inside each of these channels are thousands of tiny, circular nanostructures made out of gold, with an "antibody" surface chemistry that is designed to "trap" HSP70. As the patient’s blood flows through the channels, HSP70 proteins are trapped on the nanostructures.
“Our technique involves shining white light on the microfluidic channels,” says Professor Olivier Martin. “If a protein is caught on a nanostructure, we will observe small changes in wavelength as the light is refracted, compared with the initial light. In other words, there will be a change in color that can be observed with a spectrometer.”
According to the researchers, the new early-detection method has several advantages: fast and noninvasive, it could replace costly cancer biomarker detection techniques.
“Doctors would use our platform as a cancer screening test during their patients' regular checkups, which could lead to extremely early diagnoses,” Martin explains.
Professor Olivier Michielin, an oncologist at the Lausanne University Hospital, takes a cautious stance, commenting: “The HSP70 test seems quite interesting. However, it will be a long time before it becomes a routine test, although this protein is in fact high in patients with many types of cancer. In particular, it still needs to be proven that early HSP70 detection can actually change the way patients are treated and lead to real improvements in outcomes for specific types of cancer.”
Source: EPFL; November 2, 2012.