A better cancer trap

Blood tests for cancer are common. They’re also slow, expensive, and sometimes unreliable.

Tarek Fahmy and Mark Reed think they can change all that with a better mousetrap. Make that a better biomarker trap—part of a new blood test that the two professors hope will become quick, cheap, and accurate enough to perform in a doctor’s office.

Currently, detecting cancer biomarkers—proteins produced in response to a tumor—requires sending blood to a lab. The results take days. To improve on those tests, Fahmy, a chemical engineer, started with existing technology: nanowires, about 1/5,000th of a millimeter wide, that identify biomarkers by detecting electrical current. He teamed with electrical engineer Reed to add the trap, a chip that captures the markers from unpurified blood.

“You wash away all the other stuff,” Fahmy says, then release the biomarkers to the nanowires, which give an electronic readout. Reed, Fahmy, and colleagues published their work online in Nature Nanotechnology. Fahmy predicts the technology could be put in a device the size of an iPod, providing results in 20 minutes for as little as $1 a test.

Cancer testing can be tricky, given controversies like the one over the prostate cancer blood test—which has trouble distinguishing between tumors that need treatment and those better left alone. Could a quicker, cheaper test lead to more such problems?

Fahmy acknowledges the difficulty. “The electronics can be tweaked” to make a test more or less sensitive. But ultimately, he says, it’s up to the medical profession to set standards for testing and treatment.