- Data published in Journal of Clinical Oncology supports routine use of circulating tumor DNA (ctDNA) testing in management of stage III colon cancer patients
PALO ALTO, Calif. & ROCHESTER, Minn.–(BUSINESS WIRE)–$GH–Guardant Health, Inc. (Nasdaq: GH), a leading precision oncology company and research collaborators at Mayo Clinic and the Alliance for Clinical Trials in Oncology today announced publication of the largest study to date evaluating circulating tumor DNA (ctDNA) for MRD detection in patients with resected stage III colon cancer after surgery and before adjuvant chemotherapy. Results of the study, published in the Journal of Clinical Oncology, show that detecting ctDNA with the Guardant Reveal® blood test better predicts recurrence and overall survival than standard staging.
Researchers found that about 20 percent of patients in the phase III trial, which was presented at the 2025 American Society for Clinical Oncology (ASCO) Annual Meeting, involving more than 2,000 patients still had detectable ctDNA in their blood after surgery. Guardant Reveal identified patients at a four-to-six-fold higher rate of disease recurrence or reduced survival. Even patients with smaller tumors or fewer affected lymph nodes found as part of traditional staging had an over 6-fold higher rate of events if ctDNA was detected. The findings support the integration of tissue-free ctDNA testing into routine postoperative management to better identify patients at high risk of recurrence who may benefit from intensified surveillance or alternative adjuvant strategies.
Measuring the amount of cancer DNA in the blood, a marker known as tumor fraction, further distinguished those at the highest risk of early recurrence and worse survival. This additional layer of information may help clinicians prioritize patients who need the most intensive surveillance or consideration of alternative therapies.
“The data suggest that not only the presence of ctDNA, but the amount of ctDNA, as identified by Guardant Reveal may help refine risk beyond standard TNM staging, and could be used to guide adjuvant treatment and surveillance decisions,” said Frank Sinicrope, MD, professor of oncology and medicine at Mayo Clinic and principal investigator for the study. “ctDNA testing after surgery improves the accuracy of estimating a patient’s risk of cancer recurrence, enabling more tailored recommendations for adjuvant chemotherapy and follow-up monitoring. It also identifies high risk patients who are likely to recur despite standard treatment, and who may benefit from alternative therapeutic approaches.”
“This large study adds to growing evidence that ctDNA testing with Guardant Reveal after surgery helps answer the question patients care about most: Am I really cancer-free?” said Dr. Craig Eagle, Guardant Health Chief Medical Officer. “Personalizing care after surgery is essential as clinicians and patients decide what comes next. Guardant Reveal fits easily into routine practice and provides timely, actionable insight—helping identify patients at high risk while sparing others unnecessary treatment and anxiety.”
Today’s announcement is the latest data reinforcing the clinical utility of Guardant Reveal in molecular residual disease and beyond. Guardant recently expanded Reveal to support late-stage therapy response monitoring, enabling ctDNA-based assessment of treatment effectiveness across solid tumors. This adds to evidence from early-stage breast cancer publications that Reveal’s tissue-free approach can identify patients at elevated risk of recurrence and support more personalized care.
About Guardant Health
Guardant Health is a leading precision oncology company focused on guarding wellness and giving every person more time free from cancer. Founded in 2012, Guardant is transforming patient care by providing critical insights into what drives disease through its advanced blood and tissue tests, real-world data and AI analytics. Guardant tests help improve outcomes across all stages of care, including screening to find cancer early, monitoring for recurrence in early-stage cancer, and helping doctors select the best treatment for patients with advanced cancer. For more information, visit guardanthealth.com and follow the company on LinkedIn, X (Twitter) and Facebook.
About Mayo Clinic
Mayo Clinic is a nonprofit organization committed to innovation in clinical practice, education and research, and providing compassion, expertise and answers to everyone who needs healing. Visit the Mayo Clinic News Network for additional Mayo Clinic news.
Guardant Health Forward-Looking Statements
This press release contains forward-looking statements within the meaning of federal securities laws, including statements regarding the potential utilities, values, benefits and advantages of Guardant Health’s liquid biopsy tests or assays, which involve risks and uncertainties that could cause the actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions, and actual outcomes and results could differ materially from these statements due to a number of factors. These and additional risks and uncertainties that could affect Guardant Health’s financial and operating results and cause actual results to differ materially from those indicated by the forward-looking statements made in this press release include those discussed under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operation” and elsewhere in its Annual Report on Form 10-K for the year ended December 31, 2024 and in its other reports filed with or furnished to the Securities and Exchange Commission. The forward-looking statements in this press release are based on information available to Guardant Health as of the date hereof, and Guardant Health disclaims any obligation to update any forward-looking statements provided to reflect any change in its expectations or any change in events, conditions, or circumstances on which any such statement is based, except as required by law. These forward-looking statements should not be relied upon as representing Guardant Health’s views as of any date subsequent to the date of this press release.
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