Imagine the movie scene: The leading woman has been looking a little wan. She goes into the bathroom, opens up a test kit and approaches the toilet. As the camera remains discreetly focused on a close-up of the test package, we hear dribbling liquid in the background, and a sharply indrawn breath.
"Positive," she murmurs.
We see her emerge from the bathroom and exchange a deep, desperate look with her lover. But she doesn't say, "I'm pregnant." She says, "I have cancer."
That scene is still in the realm of science fiction, but a report just out from MIT seems to bring it a step closer. It cites a paper just out in the Proceedings of the National Academy of Sciences (link to come when available) that describes success in diagnosing cancer with a simple, paper-based test — an advance that could be particularly important for the developing countries where 70 percent of cancer deaths now occur. From the MIT press release by Anne Trafton:
The diagnostic, which works much like a pregnancy test, could reveal within minutes, based on a urine sample, whether a person has cancer. This approach has helped detect infectious diseases, and the new technology allows noncommunicable diseases to be detected using the same strategy.
The technology, developed by MIT professor and Howard Hughes Medical Institute investigator Sangeeta Bhatia, relies on nanoparticles that interact with tumor proteins called proteases, each of which can trigger release of hundreds of biomarkers that are then easily detectable in a patient’s urine.
“When we invented this new class of synthetic biomarker, we used a highly specialized instrument to do the analysis,” says Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science. “For the developing world, we thought it would be exciting to adapt it instead to a paper test that could be performed on unprocessed samples in a rural setting, without the need for any specialized equipment. The simple readout could even be transmitted to a remote caregiver by a picture on a mobile phone.”
In tests in mice, the researchers were able to accurately identify colon tumors, as well as blood clots. Bhatia says these tests represent the first step toward a diagnostic device that could someday be useful in human patients.
“This is a new idea — to create an excreted biomarker instead of relying on what the body gives you,” she says. “To prove this approach is really going to be a useful diagnostic, the next step is to test it in patient populations.”
Such technology might also prove useful in the United States, and other countries where more advanced diagnostics are available, as a simple and inexpensive alternative to imaging. “I think it would be great to bring it back to this setting, where point-of-care, image-free cancer detection, whether it’s in your home or in a pharmacy clinic, could really be transformative,” Bhatia says.
With the current version of the technology, patients would first receive an injection of the nanoparticles, then urinate onto the paper test strip. To make the process more convenient, the researchers are now working on a nanoparticle formulation that could be implanted under the skin for longer-term monitoring.