Novel Test Detects Leftover Cancer DNA in the Blood

Tumor-uninformed test detects the residual or leftover cancer DNA circulating in the blood of patients following treatment. Guardant Reveal test developed by precision oncology company Guardant Health, is "tumor-uninformed". It doesn't require knowing mutations that were present in the patient's tumor.

"The use of ctDNA, which is a type of 'liquid biopsy', is a powerful prognostic tool to detect residual disease, and many prospective trials are under way in the United States, Europe, Asia and Australia to use ctDNA to guide treatment decision-making," says lead author Aparna R. Parikh, MD, an investigator in the Division of Hematology and Oncology at MGH and an assistant professor of Medicine at Harvard Medical School.

"Most studies have used a tumor-informed ctDNA approach that requires testing of the tumor and knowledge of tumor-specific alterations, which can't be used when a patient has insufficient tumor tissue for analysis."

Parikh and her colleagues at MGH and Guardant Health evaluated the first tumor-uninformed ctDNA assay to identify residual cancer cells in patients who underwent surgery for colorectal cancer.

ctDNA results from 84 patients were analyzed and researchers examined how correctly the results correlated with cancer recurrence, they found that this "plasma only" approach was similar in sensitivity and specificity to tumor-informed approaches.

"This is one of the first studies to report on a plasma-only approach. There are advantages and disadvantages to each of the approaches," says Parikh.

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Ongoing prospective studies will provide additional information on the performance of this assay for detecting residual cancer cells and for guiding treatment decisions.

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Source-Medindia