We’re seeing encouraging progress in cancer diagnostics with news of positive results from an innovative blood test to detect circulating tumor DNA.
The test, Signatera, is described by its maker, Natera, as a “personalized and tumor-informed” circulating tumor DNA (ctDNA) assay. A study detailed in Nature affirmed its ability to predict patient outcomes with immunotherapy in a randomized clinical trial, Natera announced.
Unlike liquid biopsies designed to match patients with therapies, Natera says its Signatera test provides each individual with a customized blood test tailored to fit the unique signature of clonal mutations found in that individual's tumor. According to Natera, the test is intended to detect residual disease and recurrence, and to help optimize treatment decisions.
A personalized test supports personalized therapy
The Nature article showed evidence of the test’s accuracy in identifying residual disease in patients with a type of bladder cancer and for predicting outcomes of treatment with immunotherapy. "This opens new avenues for patient stratification, an important step in the drive towards personalized cancer therapy,” said Thomas Powles, M.D., professor, Barts Cancer Institute, and first author of the study.
Patients who tested positive for ctDNA after surgery reportedly derived a significant benefit from immunotherapy treatment and had a reported 41% improvement in survival. ctDNA-negative patients derived no benefit from the treatment. These findings appear to support the potential clinical utility of the test.
A test created ‘specifically to my tumor’
One patient, Bonnie Miller of Washington state, benefitted from Signatera’s revelation that her bladder cancer wasn’t responding to treatment, enabling her doctors to quickly switch to a different treatment. She responded well and now uses the test to monitor for recurrence. “They took my tumor sample, analyzed it and then developed this test specifically to my tumor,” she told Boston radio station WBUR. “It gave me peace of mind. Getting the results of that made me feel comfortable in enjoying life.”
Signatera reports that its test performance has been clinically validated in multiple cancer types including colorectal, non-small cell lung, and breast cancers.
At iSpecimen, we support a large number of cancer diagnostic developers, helping them get the human biospecimens they need from the patients they want in order to refine and validate their technologies. We look forward to more blood-based diagnostics becoming available in the near future, including the holy grail – a single liquid biopsy for all cancers.