New Liquid Biopsy May Change How We Diagnose Cancer
May 21, 2017 Cedars-Sinai Staff
When it comes to treating cancer, the days of needle or surgical biopsies may be numbered.
A team from Cedars-Sinai and UCLA is using a new blood analysis technique with a tiny device that can diagnose and track the progression of cancer based on tumor cells circulating in the blood. The postage-stamp-sized device is called the NanoVelcro Chip.
"The development of the NanoVelcro Chip has been a beautiful marriage between medicine and engineering," says Dr. Edwin Posadas, medical director of the Cedars-Sinai Urologic Oncology Program and one of the lead investigators. "This synergy has allowed us to apply the technology to very important problems in prostate cancer and quite possibly melanoma, pancreatic, lung, and kidney cancer. We've slated these and other cancers for development."
Dr. Posadas and his UCLA partner, Hsian-Rong Tseng, PhD, are first focusing on prostate cancer, which kills 27,000 men yearly.
"If we can make a dent there, it’s a huge deal. And the principles we’re learning could have even broader applications."
"When it comes to treating cancer, the days of needle or surgical biopsies may be numbered."
How 'liquid biopsies' work
Some cancer cells break away from tumors and travel through the blood, looking for places in the body to grow new tumors. By capturing these circulating tumor cells, doctors could detect and analyze an individual patient’s cancer to make a diagnosis and potentially tailor a specific treatment.
The NanoVelcro Chip is coated with antibodies—proteins that recognize the circulating tumor cells—on nanowires one-thousandth the width of a human hair. A small amount of blood is run through the chip, and the tumor cells stick to the nanowires like Velcro. (Hence the chip's name.)
"But we take it a step further," Dr. Posadas adds. "Once that cell is captured, we have the capacity to take it off the NanoVelcro and open the DNA. We're going beyond saying, 'It's a prostate cancer.' We can identify a mutation or androgen receptor aberration that may strongly affect how a patient needs to be treated."
Maximizing benefits and minimizing harm in therapy
Once there is a cancer diagnosis, Dr. Posadas and his team believe, a liquid biopsy (sometimes called a 'blood biopsy') will help match patients to the appropriate therapy by better describing how their cancer changes over time. Otherwise, oncologists still follow prostate specific antigen (PSA) levels, using a test that came from the laboratories of Stanford in 1983. But PSA represents only one facet of this disease.
Because prostate cancer frequently grows slowly, patients are often monitored over long periods of time.
"We can treat the cells we identify on our chip the same way that we treat cells from a surgical or needle biopsy," Dr. Posadas explains. "We can tear apart their RNA and DNA to understand their molecular characteristics. So we may be able to further personalize therapy, not just by one biopsy done 10 years ago, but by taking a blood sample today, getting a molecular profile back within a week and making a treatment assignment that we can monitor."
Tracking how the cancer is developing could help clinicians pick the best therapy and the best time to treat patients. It also cuts down on the need for invasive examinations like needle or surgical biopsies.
"No one wants a needle in them every 4 weeks or a surgical biopsy to take out a piece of tumor. We think this could be as simple as a blood test, something with no more gravity than a blood pressure reading or weight check at the doctor's office. That is the future of medicine."
"It's tremendous to be part of a bigger effort in which our government no longer wants to see changes in cancer in 10 years. The timeline we're pushed towards is the next 2 to 3 years."
There is support for that prediction from the National Cancer Institute and US Cancer Moonshot program, an initiative led by former Vice President Joe Biden to make cancer prevention and therapy more widely available.
Dr. Posadas and his research partners are sharing insights on the molecular structure of prostate cancer through a Moonshot project called Blood Profiling Atlas in Cancer (BloodPAC). They hope to disseminate a more refined understanding of the disease—one that's comparable to current knowledge of mutations in lung and breast cancer.
"It started in a very passionate and personal way," Dr. Posadas says of his work. "Now it's tremendous to be part of a bigger effort in which our government no longer wants to see changes in cancer in 10 years. The timeline we're pushed towards is the next 2 to 3 years in the clinic."