- Researchers at Stanford University say they are developing a wearable device that can measure cancer tumors.
- The device, known as FAST, has built-in sensors that are designed to keep track of tumor growth and shrinkage.
- Experts say the device has potential, but it may be more applicable in research than it is in actual clinical practice.
Doctors have more tools than ever for treating cancer, but the method for measuring the size of tumors located just under the skin is often primitive.
Many times it involves a pinch test performed by hand, with simple metal calipers.
However, a new device developed by Stanford University researchers could bring the measurement of subcutaneous tumors up to 21st-century standards.
Dubbed the “Flexible Autonomous Sensor measuring Tumors (FAST),” the small, stretchable device can be placed over the tumor site like a patch. Built-in sensors monitor tumor growth or shrinkage.
The battery-powered FAST device then autonomously and automatically sends readings to a smartphone app.
Tumor measurements by FAST are accurate to one-hundredth of a millimeter, or 10 micrometers, according to the Stanford Wearable Electronics Initiative, which developed the device.
In addition to being accurate and hands-free, FAST promises to improve the speed with which tumors can be measured, which has implications for cancer research as well as treatment, developers said.
“It is a deceptively simple design,” Alex Abramson, Ph.D., an assistant professor in the chemical and biomolecular engineering department at Georgia Tech and the first author of a study about FAST published today in the journal Science Advances, said in a press statement. “But these inherent advantages should be very interesting to the pharmaceutical and oncological communities. FAST could significantly expedite, automate and lower the cost of the process of screening cancer therapies.”
“The electronic strain sensor is non-invasive and provides real-time information,” Dr. Anton Bilchik, a surgical oncologist and division chair of general surgery at Providence Saint John’s Health Center and chief of medicine at the Saint John’s Cancer Institute in California, told Healthline. “This has definite clinical relevance but will require extensive clinical evaluation.”
Dr. Paul Fu, the chief medical information officer at City of Hope, a cancer research and treatment organization in California, told Healthline that there’s “lots of potential” for the device, although perhaps more for research than in clinical practice.
“The most important thing about this technology is its ability to monitor in vivo,” said Fu, such as in human clinical drug trials or animal studies. “The challenge is, how significant is the data — what is the clinical significance of 10 micrometers of change?”
“This device is intriguing and may have potential application to the treatment monitoring of human tumors,” Dr. Richard Reitherman, the medical director of breast imaging at the MemorialCare Breast Center at Orange Coast Medical Center in California, told Healthline. “However, it is not clear that short-term monitoring of treatment effects on the order of minutes will be of value. The treatment response in human tumors may take weeks or longer to produce the optimal local environment to maintain sustained delivery to the tumor.”
The FAST sensor consists of a thin layer of gold sensors embedded in a stretchable, skin-like polymer material. The sensors detect minute changes in tumor size and shape by reacting to stretching or contraction of the patch.
“Human biology and tumor sizes are generally much more heterogenous and larger, respectively, than the animal models used in this research,” Reitherman said. “In addition, certain human tumors are not a single mass but made up of multiple tumor masses and masses that are odd shapes would be more difficult to encircle in a device. Also, with the exception of superficial tumors, the device would need to be installed or implanted surgically in the organ that surrounds the tumor mass.”
In animal studies, such as tests of cancer drugs on mice with subcutaneous tumors, the FAST device can deliver real-time data, whereas the caliper and bioluminescence measurements currently in use can take weeks to detect changes, according to Stanford researchers.
The FAST device — which costs about $60 to assemble and is reusable — could evolve into an inexpensive diagnostic tool.
Fu, for example, said that while daily monitoring of tumor size may not be that important when treating melanoma or other subcutaneous tumors, the FAST device could prove useful for weekly check-ins to measure progress in chemotherapy.
Whether for treatment or research, FAST could offer advantages over other methods of measuring tumors.
“With bioluminescence or calipers, you need someone with some skills,” Fu said. “You have to be good and consistent in terms of measurement.”
FAST, by contrast, operates autonomously and has been shown to deliver more precise measurements, at least in animal studies.