In traditional cancer tests such as CT scans, a physician must analyze medical imaging to determine if a survivor’s cancer has returned. That means the recurrent tumor must be large enough for the doctor to see it. “Depending on certain factors, a CT scan can struggle to accurately detect tumors less than one centimeter in size,” says Solomon Moshkevich, general manager of oncology at Natera, a personalized genetic testing and diagnostics company. “By that point, you’re talking about a pretty sizable tumor.”
The Natera team has developed innovative cancer screening technology that doesn’t rely on the human eye. It’s a personalized blood test that can detect minuscule traces of cancer in the bloodstream. Each test is custom built to identify the unique genetic mutations previously observed in a patient’s tumor and can detect a single molecule of tumor DNA up to two years before it can be detected by imaging.
The test, called Signatera, can detect many types of residual disease—the cancer cells that remain in the body after treatment—including cells associated with colorectal, breast, and lung cancer. Signatera was used in more than 75,000 tests in 2021, bringing a new cancer monitoring method to a broad population of patients. That approach has helped earn Natera a spot on Fast Company‘s list of the world’s Most Innovative Companies.
DETECTION MONTHS EARLIER
Signatera’s groundbreaking technology was originally developed for noninvasive, prenatal screening. It allows scientists to analyze free-floating DNA in a pregnant woman’s bloodstream to identify Down Syndrome and other severe genetic conditions that may be present in an unborn child.
After finding success and improving outcomes in the prenatal community, Natera’s researchers sought to uncover other uses for their innovation. At the time, scientific literature revealed that tumors can also leak free-floating DNA, known as cell-free DNA (cfDNA). “A major problem that we realized we could solve is detection of residual disease,” Moshkevich says.
Natera successfully introduced its first prototype of the Signatera technology back in 2015, analyzing blood samples from a clinical trial in early-stage lung cancer. (In fact, Moshkevich notes, researchers also used early versions of the tech to successfully monitor his own father’s gastroesophageal cancer.)
To initiate its customized tests, Signatera scientists first sequence the DNA from a block of the patient’s tumor to identify its unique mutations. Then, when the patient’s physician orders a simple blood draw, Signatera analyzes the blood for the exact mutations that were present in the original tumor. Because the technique is personalized and tumor-informed, Moshkevich says false positives, which are common in CT scans, are rare.
INFORMING BETTER TREATMENT DECISIONS
When a patient is diagnosed with cancer, physicians often suggest multistep treatment plans to eradicate the disease. But Moshkevich says this can contribute to systematic overtreatment. “Lots of patients who are already cured by surgery are going through chemotherapy—which is super toxic, as you can imagine—to try to eliminate the chance of recurrence,” he says. “Up until now, physicians have had no way to assess which patients were cured and which patients still might have micrometastatic or small traces of tumor DNA still floating in the blood that might cause a recurrence later.”
With Signatera’s capabilities, healthcare providers can help patients understand more about which treatment options might make sense—and to help people achieve peace of mind. For patients who are currently in treatment, monitoring regularly with Signatera (in conjunction with imaging) can also indicate earlier whether the tumor burden is going up or down in response to therapy. Ultimately, the goal is to give healthcare providers a more effective tool in making patient-centric treatment decisions. “We’re very excited to help as many patients as possible beat cancer,” Moshkevich says.