The Gift of Grab
An experimental device snags tumor cells like Velcro to speed cancer diagnosis and predict disease spread.
The dark channels in the NanoVelcro Chip are outfitted with nanowires 1,000 times thinner than a human hair. They are coated with antibodies or proteins that snag passing tumor cells. Scientists then can analyze the cells, characterize the cancer, and possibly predict whether it will spread. A polymer casing snaps onto the chip and directs fluids through it during laboratory analysis.
Technology in 2017 is many things: nanosized, wireless, hands-free, tidy. Medicine, though, can be messy. The human body is an organic system of wiring and biochemical reactions — and sometimes the only way to assess what is happening inside is to get under someone’s skin, literally.
Thus, the standard approach in the clinic for performing a biopsy is to insert a long needle into the tumor and draw out cells for examination. The procedure is used to diagnose diseases such as cancer and, if cancer is present, to track its progress and help doctors choose better treatments. Often, several samples are collected because different areas of a tumor may exhibit distinctive characteristics. Even with multiple samples of a cancerous tumor, a physician may have difficulty determining how aggressive the cancer is or how it is responding to treatment.
The procedure is, at best, a nuisance, but at worst carries a risk of infection, bleeding, and other forms of injury. This is especially problematic with prostate biopsies that are drawn through the bacteria-laden rectal wall. Between 1 and 3 percent of men will develop a severe and potentially antibiotic-resistant infection after having a traditional biopsy.
A postage-stamp-sized chip may dramatically lessen risks while also enriching tumor analysis. The experimental device, the NanoVelcro Chip, could replace traditional biopsies with a simple blood draw. It works by “grabbing,” like Velcro, rogue cells that have broken away from tumors and are traveling through the bloodstream, looking for places in the body to spread.
A team of investigators from Cedars-Sinai and UCLA is using the chip to conduct “liquid biopsies,” running a blood sample through the NanoVelcro device in a lab and then analyzing the so-called circulating tumor cells it captures to determine how aggressive and advanced the cancer is.
“It’s far better to draw a tube of blood once a month to monitor cancer than to make patients undergo repeated surgical procedures,” says Edwin Posadas, MD, medical director of the Urologic Oncology Program at the Cedars-Sinai Samuel Oschin Comprehensive Cancer Institute and one of the project’s lead investigators. “The potential power of this technology lies in its capacity to provide information that is equal to, or even superior, to traditional tumor sampling by invasive procedures.”
Use of the chip for liquid biopsies could allow doctors to regularly and easily monitor cancer-related changes in patients, such as how well they’re responding to treatment. The team’s research also has advanced understanding of how prostate and other cancers evolve. The work earned the lead investigators a place in the U.S. Cancer Moonshot program, an initiative led by former Vice President Joe Biden that aims to help prevent cancer and make more therapies available to more patients.