They develop a new test that detects residual cancer DNA in the blood without relying on tumor data


After cancer patients undergo surgery to remove a tumor and sometimes additional chemotherapy, tools are used to identify patients at increased risk of recurrence. A new study from Massachusetts General Hospital (United States) has developed the first “non-tumor” test that detects cancer DNA that circulates in the blood of patients after treatment.

The test, called ‘Guardant Reveal’, developed by precision oncology company Guardant Health, is “tumor free” because, unlike previous tests to detect circulating tumor DNA (cDNA) in blood, this The test does not require knowing the specific mutations that were present in the patient’s tumor.

“The use of cDNA, which is a type of ‘liquid biopsy,’ is a powerful prognostic tool for detecting residual disease, and many prospective trials are underway in the United States, Europe, Asia, and Australia to use cDNA with the in order to guide decision-making about treatment.Most studies have used a tumor-informed cDNA approach that requires analysis of the tumor and knowledge of the specific abnormalities of the tumor, which cannot be used when a patient it doesn’t have enough tumor tissue for analysis, “explains Dr. Aparna R. Parikh, lead author of the study.

In this study, published in the journal ‘Clinical Cancer Research’, they evaluated the first non-tumor reported cDNA assay to detect residual cancer cells in patients operated on for colorectal cancer. Rather than relying on DNA sequencing from individual patient tumors, the method looked for known cancer-specific alterations.

When researchers analyzed ctDNA results from 84 patients and examined how closely the results correlated with cancer recurrence, they found that this “plasma only” approach was similar in sensitivity and specificity to tumor-reported approaches. .

“This is one of the first studies to report on a plasma-only approach. There are trade-offs to each of the approaches,” says Parikh, who notes that ongoing prospective studies will provide additional information on the performance of this trial for detect residual cancer cells and to guide treatment decisions.